.gitattributes

@@ -1,2 +0,0 @@
-* linguist-vendored
-*.java linguist-vendored=false

build.gradle

@@ -1,10 +1,11 @@
 plugins {
+    id "de.marcphilipp.nexus-publish" version "0.4.0"
+    id "io.codearte.nexus-staging" version "0.21.1"
+    id "org.xbib.gradle.plugin.asciidoctor" version "2.5.2.2"
+    id "org.cyclonedx.bom" version "1.7.2"
+    id "com.github.spotbugs" version "5.0.13"
+    id "checkstyle"
     id "pmd"
-    id 'maven-publish'
-    id 'signing'
-    id "io.github.gradle-nexus.publish-plugin" version "2.0.0-rc-1"
-    id "org.cyclonedx.bom" version "1.7.4"
-    id "org.xbib.gradle.plugin.asciidoctor" version "3.0.0"
 }
 
 wrapper {
@@ -17,9 +18,9 @@ ext {
     name = 'marc'
     description = 'MARC bibliographic data processing library for Java'
     inceptionYear = '2016'
-    url = 'https://xbib.org/' + user + '/' + name
-    scmUrl = 'https://xbib.org/' + user + '/' + name
-    scmConnection = 'scm:git:git://xbib.org/' + user + '/' + name + '.git'
+    url = 'https://github.com/' + user + '/' + name
+    scmUrl = 'https://github.com/' + user + '/' + name
+    scmConnection = 'scm:git:git://github.com/' + user + '/' + name + '.git'
     scmDeveloperConnection = 'scm:git:ssh://git@github.com:' + user + '/' + name + '.git'
     issueManagementSystem = 'Github'
     issueManagementUrl = ext.scmUrl + '/issues'
@@ -30,21 +31,22 @@ ext {
 apply plugin: 'java-library'
 
 dependencies {
-    testImplementation testLibs.charactersets
-    testImplementation testLibs.json
-    testImplementation testLibs.xalan
-    testImplementation testLibs.xmlunit
-    testImplementation(testLibs.mockito) {
+    testImplementation libs.charactersets
+    testImplementation libs.json
+    testImplementation libs.xalan
+    testImplementation libs.xmlunit
+    testImplementation(libs.mockito) {
         exclude group: 'org.hamcrest'
     }
-    testImplementation testLibs.marc4j
+    testImplementation libs.marc4j
 }
 
+apply from: rootProject.file('gradle/ide/idea.gradle')
 apply from: rootProject.file('gradle/compile/java.gradle')
 apply from: rootProject.file('gradle/test/junit5.gradle')
 apply from: rootProject.file('gradle/repositories/maven.gradle')
+apply from: rootProject.file('gradle/publishing/publication.gradle')
 apply from: rootProject.file('gradle/quality/cyclonedx.gradle')
+apply from: rootProject.file('gradle/quality/spotbugs.gradle')
+apply from: rootProject.file('gradle/quality/checkstyle.gradle')
 apply from: rootProject.file('gradle/quality/pmd.gradle')
-apply from: rootProject.file('gradle/publish/maven.gradle')
-apply from: rootProject.file('gradle/publish/sonatype.gradle')
-apply from: rootProject.file('gradle/publish/forgejo.gradle')

config/checkstyle/checkstyle.xml

@@ -0,0 +1,323 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+        "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
+        "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">
+
+<!-- This is a checkstyle configuration file. For descriptions of
+what the following rules do, please see the checkstyle configuration
+page at http://checkstyle.sourceforge.net/config.html -->
+
+<module name="Checker">
+
+    <module name="FileTabCharacter">
+        <!-- Checks that there are no tab characters in the file.
+        -->
+    </module>
+
+    <module name="NewlineAtEndOfFile">
+        <property name="lineSeparator" value="lf"/>
+    </module>
+
+    <module name="RegexpSingleline">
+        <!-- Checks that FIXME is not used in comments.  TODO is preferred.
+        -->
+        <property name="format" value="((//.*)|(\*.*))FIXME" />
+        <property name="message" value='TODO is preferred to FIXME.  e.g. "TODO(johndoe): Refactor when v2 is released."' />
+    </module>
+
+    <module name="RegexpSingleline">
+        <!-- Checks that TODOs are named.  (Actually, just that they are followed
+             by an open paren.)
+        -->
+        <property name="format" value="((//.*)|(\*.*))TODO[^(]" />
+        <property name="message" value='All TODOs should be named.  e.g. "TODO(johndoe): Refactor when v2 is released."' />
+    </module>
+
+    <module name="JavadocPackage">
+        <!-- Checks that each Java package has a Javadoc file used for commenting.
+          Only allows a package-info.java, not package.html. -->
+    </module>
+
+    <!-- All Java AST specific tests live under TreeWalker module. -->
+    <module name="TreeWalker">
+
+        <!--
+
+        IMPORT CHECKS
+
+        -->
+
+        <module name="RedundantImport">
+            <!-- Checks for redundant import statements. -->
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="ImportOrder">
+            <!-- Checks for out of order import statements. -->
+
+            <property name="severity" value="warning"/>
+            <property name="groups" value="com,junit,net,org,java,javax"/>
+            <!-- This ensures that static imports go first. -->
+            <property name="option" value="top"/>
+            <property name="tokens" value="STATIC_IMPORT, IMPORT"/>
+        </module>
+
+        <!--
+
+        JAVADOC CHECKS
+
+        -->
+
+        <!-- Checks for Javadoc comments.                     -->
+        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
+        <module name="JavadocMethod">
+            <property name="scope" value="protected"/>
+            <property name="severity" value="warning"/>
+            <property name="allowMissingJavadoc" value="true"/>
+            <property name="allowMissingParamTags" value="true"/>
+            <property name="allowMissingReturnTag" value="true"/>
+            <property name="allowMissingThrowsTags" value="true"/>
+            <property name="allowThrowsTagsForSubclasses" value="true"/>
+            <property name="allowUndeclaredRTE" value="true"/>
+        </module>
+
+        <module name="JavadocType">
+            <property name="scope" value="protected"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="JavadocStyle">
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!--
+
+        NAMING CHECKS
+
+        -->
+
+        <!-- Item 38 - Adhere to generally accepted naming conventions -->
+
+        <module name="PackageName">
+            <!-- Validates identifiers for package names against the
+              supplied expression. -->
+            <!-- Here the default checkstyle rule restricts package name parts to
+              seven characters, this is not in line with common practice at Google.
+            -->
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]{1,})*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="TypeNameCheck">
+            <!-- Validates static, final fields against the
+            expression "^[A-Z][a-zA-Z0-9]*$". -->
+            <metadata name="altname" value="TypeName"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="ConstantNameCheck">
+            <!-- Validates non-private, static, final fields against the supplied
+            public/package final fields "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$". -->
+            <metadata name="altname" value="ConstantName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="false"/>
+            <property name="format" value="^([A-Z][A-Z0-9]*(_[A-Z0-9]+)*|FLAG_.*)$"/>
+            <message key="name.invalidPattern"
+                     value="Variable ''{0}'' should be in ALL_CAPS (if it is a constant) or be private (otherwise)."/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="StaticVariableNameCheck">
+            <!-- Validates static, non-final fields against the supplied
+            expression "^[a-z][a-zA-Z0-9]*_?$". -->
+            <metadata name="altname" value="StaticVariableName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="true"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*_?$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MemberNameCheck">
+            <!-- Validates non-static members against the supplied expression. -->
+            <metadata name="altname" value="MemberName"/>
+            <property name="applyToPublic" value="true"/>
+            <property name="applyToProtected" value="true"/>
+            <property name="applyToPackage" value="true"/>
+            <property name="applyToPrivate" value="true"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="MethodNameCheck">
+            <!-- Validates identifiers for method names. -->
+            <metadata name="altname" value="MethodName"/>
+            <property name="format" value="^[a-z][a-zA-Z0-9]*(_[a-zA-Z0-9]+)*$"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="ParameterName">
+            <!-- Validates identifiers for method parameters against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalFinalVariableName">
+            <!-- Validates identifiers for local final variables against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="LocalVariableName">
+            <!-- Validates identifiers for local variables against the
+              expression "^[a-z][a-zA-Z0-9]*$". -->
+            <property name="severity" value="warning"/>
+        </module>
+
+
+        <!--
+
+        LENGTH and CODING CHECKS
+
+        -->
+
+        <module name="LineLength">
+            <!-- Checks if a line is too long. -->
+            <property name="max" value="${com.puppycrawl.tools.checkstyle.checks.sizes.LineLength.max}" default="128"/>
+            <property name="severity" value="error"/>
+
+            <!--
+              The default ignore pattern exempts the following elements:
+                - import statements
+                - long URLs inside comments
+            -->
+
+            <property name="ignorePattern"
+                      value="${com.puppycrawl.tools.checkstyle.checks.sizes.LineLength.ignorePattern}"
+                      default="^(package .*;\s*)|(import .*;\s*)|( *(\*|//).*https?://.*)$"/>
+        </module>
+
+        <module name="LeftCurly">
+            <!-- Checks for placement of the left curly brace ('{'). -->
+            <property name="severity" value="warning"/>
+        </module>
+
+        <module name="RightCurly">
+            <!-- Checks right curlies on CATCH, ELSE, and TRY blocks are on
+            the same line. e.g., the following example is fine:
+            <pre>
+              if {
+                ...
+              } else
+            </pre>
+            -->
+            <!-- This next example is not fine:
+            <pre>
+              if {
+                ...
+              }
+              else
+            </pre>
+            -->
+            <property name="option" value="same"/>
+            <property name="severity" value="warning"/>
+        </module>
+
+        <!-- Checks for braces around if and else blocks -->
+        <module name="NeedBraces">
+            <property name="severity" value="warning"/>
+            <property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
+        </module>
+
+        <module name="UpperEll">
+            <!-- Checks that long constants are defined with an upper ell.-->
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="FallThrough">
+            <!-- Warn about falling through to the next case statement.  Similar to
+            javac -Xlint:fallthrough, but the check is suppressed if a single-line comment
+            on the last non-blank line preceding the fallen-into case contains 'fall through' (or
+            some other variants which we don't publicized to promote consistency).
+            -->
+            <property name="reliefPattern"
+                      value="fall through|Fall through|fallthru|Fallthru|falls through|Falls through|fallthrough|Fallthrough|No break|NO break|no break|continue on"/>
+            <property name="severity" value="error"/>
+        </module>
+
+
+        <!--
+
+        MODIFIERS CHECKS
+
+        -->
+
+        <module name="ModifierOrder">
+            <!-- Warn if modifier order is inconsistent with JLS3 8.1.1, 8.3.1, and
+                 8.4.3.  The prescribed order is:
+                 public, protected, private, abstract, static, final, transient, volatile,
+                 synchronized, native, strictfp
+              -->
+        </module>
+
+
+        <!--
+
+        WHITESPACE CHECKS
+
+        -->
+
+        <module name="WhitespaceAround">
+            <!-- Checks that various tokens are surrounded by whitespace.
+                 This includes most binary operators and keywords followed
+                 by regular or curly braces.
+            -->
+            <property name="tokens" value="ASSIGN, BAND, BAND_ASSIGN, BOR,
+        BOR_ASSIGN, BSR, BSR_ASSIGN, BXOR, BXOR_ASSIGN, COLON, DIV, DIV_ASSIGN,
+        EQUAL, GE, GT, LAND, LE, LITERAL_CATCH, LITERAL_DO, LITERAL_ELSE,
+        LITERAL_FINALLY, LITERAL_FOR, LITERAL_IF, LITERAL_RETURN,
+        LITERAL_SYNCHRONIZED, LITERAL_TRY, LITERAL_WHILE, LOR, LT, MINUS,
+        MINUS_ASSIGN, MOD, MOD_ASSIGN, NOT_EQUAL, PLUS, PLUS_ASSIGN, QUESTION,
+        SL, SL_ASSIGN, SR_ASSIGN, STAR, STAR_ASSIGN"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="WhitespaceAfter">
+            <!-- Checks that commas, semicolons and typecasts are followed by
+                 whitespace.
+            -->
+            <property name="tokens" value="COMMA, SEMI, TYPECAST"/>
+        </module>
+
+        <module name="NoWhitespaceAfter">
+            <!-- Checks that there is no whitespace after various unary operators.
+                 Linebreaks are allowed.
+            -->
+            <property name="tokens" value="BNOT, DEC, DOT, INC, LNOT, UNARY_MINUS,
+        UNARY_PLUS"/>
+            <property name="allowLineBreaks" value="true"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="NoWhitespaceBefore">
+            <!-- Checks that there is no whitespace before various unary operators.
+                 Linebreaks are allowed.
+            -->
+            <property name="tokens" value="SEMI, DOT, POST_DEC, POST_INC"/>
+            <property name="allowLineBreaks" value="true"/>
+            <property name="severity" value="error"/>
+        </module>
+
+        <module name="ParenPad">
+            <!-- Checks that there is no whitespace before close parens or after
+                 open parens.
+            -->
+            <property name="severity" value="warning"/>
+        </module>
+
+    </module>
+</module>
+

config/checkstyle/suppressions.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC
+        "-//Puppy Crawl//DTD Suppressions 1.1//EN"
+        "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
+<suppressions>
+    <suppress checks="." files="[\\/]generated-src[\\/].*\.java$"/>
+</suppressions>

config/pmd/category/java/categories.properties

@@ -0,0 +1,13 @@
+#
+# BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+#
+
+rulesets.filenames=\
+    category/java/bestpractices.xml,\
+    category/java/codestyle.xml,\
+    category/java/design.xml,\
+    category/java/documentation.xml,\
+    category/java/errorprone.xml,\
+    category/java/multithreading.xml,\
+    category/java/performance.xml,\
+    category/java/security.xml

config/pmd/category/java/documentation.xml

@@ -0,0 +1,144 @@
+<?xml version="1.0"?>
+
+<ruleset name="Documentation"
+         xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that are related to code documentation.
+    </description>
+
+    <rule name="CommentContent"
+          since="5.0"
+          message="Invalid words or phrases found"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentContentRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentcontent">
+        <description>
+            A rule for the politically correct... we don't want to offend anyone.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+//OMG, this is horrible, Bob is an idiot !!!
+]]>
+        </example>
+    </rule>
+
+    <rule name="CommentRequired"
+          since="5.1"
+          message="Comment is required"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentRequiredRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentrequired">
+        <description>
+            Denotes whether comments are required (or unwanted) for specific language elements.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+/**
+*
+*
+* @author Jon Doe
+*/
+]]>
+        </example>
+    </rule>
+
+    <rule name="CommentSize"
+          since="5.0"
+          message="Comment is too large"
+          class="net.sourceforge.pmd.lang.java.rule.documentation.CommentSizeRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#commentsize">
+        <description>
+            Determines whether the dimensions of non-header comments found are within the specified limits.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+/**
+*
+*   too many lines!
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*
+*/
+]]>
+        </example>
+    </rule>
+
+    <rule name="UncommentedEmptyConstructor"
+          language="java"
+          since="3.4"
+          message="Document empty constructor"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#uncommentedemptyconstructor">
+        <description>
+            Uncommented Empty Constructor finds instances where a constructor does not
+            contain statements, but there is no comment. By explicitly commenting empty
+            constructors it is easier to distinguish between intentional (commented)
+            and unintentional empty constructors.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//ConstructorDeclaration[@Private='false']
+                        [count(BlockStatement) = 0 and ($ignoreExplicitConstructorInvocation = 'true' or not(ExplicitConstructorInvocation)) and @containsComment = 'false']
+                        [not(../Annotation/MarkerAnnotation/Name[pmd-java:typeIs('javax.inject.Inject')])]
+]]>
+                </value>
+            </property>
+            <property name="ignoreExplicitConstructorInvocation" type="Boolean" description="Ignore explicit constructor invocation when deciding whether constructor is empty or not" value="false"/>
+        </properties>
+        <example>
+            <![CDATA[
+public Foo() {
+  // This constructor is intentionally empty. Nothing special is needed here.
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UncommentedEmptyMethodBody"
+          language="java"
+          since="3.4"
+          message="Document empty method body"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_documentation.html#uncommentedemptymethodbody">
+        <description>
+            Uncommented Empty Method Body finds instances where a method body does not contain
+            statements, but there is no comment. By explicitly commenting empty method bodies
+            it is easier to distinguish between intentional (commented) and unintentional
+            empty methods.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//MethodDeclaration/Block[count(BlockStatement) = 0 and @containsComment = 'false']
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public void doSomething() {
+}
+]]>
+        </example>
+    </rule>
+
+</ruleset>

config/pmd/category/java/multithreading.xml

@@ -0,0 +1,393 @@
+<?xml version="1.0"?>
+
+<ruleset name="Multithreading"
+         xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that flag issues when dealing with multiple threads of execution.
+    </description>
+
+    <rule name="AvoidSynchronizedAtMethodLevel"
+          language="java"
+          since="3.0"
+          message="Use block level rather than method level synchronization"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidsynchronizedatmethodlevel">
+        <description>
+            Method-level synchronization can cause problems when new code is added to the method.
+            Block-level synchronization helps to ensure that only the code that needs synchronization
+            gets it.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>//MethodDeclaration[@Synchronized='true']</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class Foo {
+  // Try to avoid this:
+  synchronized void foo() {
+  }
+  // Prefer this:
+  void bar() {
+    synchronized(this) {
+    }
+  }
+
+  // Try to avoid this for static methods:
+  static synchronized void fooStatic() {
+  }
+
+  // Prefer this:
+  static void barStatic() {
+    synchronized(Foo.class) {
+    }
+  }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="AvoidThreadGroup"
+          language="java"
+          since="3.6"
+          message="Avoid using java.lang.ThreadGroup; it is not thread safe"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidthreadgroup">
+        <description>
+            Avoid using java.lang.ThreadGroup; although it is intended to be used in a threaded environment
+            it contains methods that are not thread-safe.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//AllocationExpression/ClassOrInterfaceType[pmd-java:typeIs('java.lang.ThreadGroup')]|
+//PrimarySuffix[contains(@Image, 'getThreadGroup')]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class Bar {
+    void buz() {
+        ThreadGroup tg = new ThreadGroup("My threadgroup");
+        tg = new ThreadGroup(tg, "my thread group");
+        tg = Thread.currentThread().getThreadGroup();
+        tg = System.getSecurityManager().getThreadGroup();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="AvoidUsingVolatile"
+          language="java"
+          since="4.1"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          message="Use of modifier volatile is not recommended."
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#avoidusingvolatile">
+        <description>
+            Use of the keyword 'volatile' is generally used to fine tune a Java application, and therefore, requires
+            a good expertise of the Java Memory Model. Moreover, its range of action is somewhat misknown. Therefore,
+            the volatile keyword should not be used for maintenance purpose and portability.
+        </description>
+        <priority>2</priority>
+        <properties>
+            <property name="xpath">
+                <value>//FieldDeclaration[contains(@Volatile,'true')]</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class ThrDeux {
+  private volatile String var1; // not suggested
+  private          String var2; // preferred
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="DoNotUseThreads"
+          language="java"
+          since="4.1"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          message="To be compliant to J2EE, a webapp should not use any thread."
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#donotusethreads">
+        <description>
+            The J2EE specification explicitly forbids the use of threads.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>//ClassOrInterfaceType[@Image = 'Thread' or @Image = 'Runnable']</value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+// This is not allowed
+public class UsingThread extends Thread {
+
+}
+
+// Neither this,
+public class OtherThread implements Runnable {
+    // Nor this ...
+    public void methode() {
+        Runnable thread = new Thread(); thread.run();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="DontCallThreadRun"
+          language="java"
+          since="4.3"
+          message="Don't call Thread.run() explicitly, use Thread.start()"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          typeResolution="true"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#dontcallthreadrun">
+        <description>
+            Explicitly calling Thread.run() method will execute in the caller's thread of control.  Instead, call Thread.start() for the intended behavior.
+        </description>
+        <priority>4</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//StatementExpression/PrimaryExpression
+[
+    PrimaryPrefix
+    [
+        ./Name[ends-with(@Image, '.run') or @Image = 'run']
+        and substring-before(Name/@Image, '.') =//VariableDeclarator/VariableDeclaratorId/@Image
+            [../../../Type/ReferenceType/ClassOrInterfaceType[pmd-java:typeIs('java.lang.Thread')]]
+        or (./AllocationExpression/ClassOrInterfaceType[pmd-java:typeIs('java.lang.Thread')]
+        and ../PrimarySuffix[@Image = 'run'])
+    ]
+]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+Thread t = new Thread();
+t.run();            // use t.start() instead
+new Thread().run(); // same violation
+]]>
+        </example>
+    </rule>
+
+    <rule name="DoubleCheckedLocking"
+          language="java"
+          since="1.04"
+          message="Double checked locking is not thread safe in Java."
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.DoubleCheckedLockingRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#doublecheckedlocking">
+        <description>
+            Partially created objects can be returned by the Double Checked Locking pattern when used in Java.
+            An optimizing JRE may assign a reference to the baz variable before it calls the constructor of the object the
+            reference points to.
+
+            Note: With Java 5, you can make Double checked locking work, if you declare the variable to be `volatile`.
+
+            For more details refer to: &lt;http://www.javaworld.com/javaworld/jw-02-2001/jw-0209-double.html>
+            or &lt;http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html>
+        </description>
+        <priority>1</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    /*volatile */ Object baz = null; // fix for Java5 and later: volatile
+    Object bar() {
+        if (baz == null) { // baz may be non-null yet not fully created
+            synchronized(this) {
+                if (baz == null) {
+                    baz = new Object();
+                }
+              }
+        }
+        return baz;
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="NonThreadSafeSingleton"
+          since="3.4"
+          message="Singleton is not thread safe"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.NonThreadSafeSingletonRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#nonthreadsafesingleton">
+        <description>
+            Non-thread safe singletons can result in bad state changes. Eliminate
+            static singletons if possible by instantiating the object directly. Static
+            singletons are usually not needed as only a single instance exists anyway.
+            Other possible fixes are to synchronize the entire method or to use an
+            [initialize-on-demand holder class](https://en.wikipedia.org/wiki/Initialization-on-demand_holder_idiom).
+
+            Refrain from using the double-checked locking pattern. The Java Memory Model doesn't
+            guarantee it to work unless the variable is declared as `volatile`, adding an uneeded
+            performance penalty. [Reference](http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html)
+
+            See Effective Java, item 48.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+private static Foo foo = null;
+
+//multiple simultaneous callers may see partially initialized objects
+public static Foo getFoo() {
+    if (foo==null) {
+        foo = new Foo();
+    }
+    return foo;
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UnsynchronizedStaticDateFormatter"
+          since="3.6"
+          deprecated="true"
+          message="Static DateFormatter objects should be accessed in a synchronized manner"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.UnsynchronizedStaticDateFormatterRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#unsynchronizedstaticdateformatter">
+        <description>
+            SimpleDateFormat instances are not synchronized. Sun recommends using separate format instances
+            for each thread. If multiple threads must access a static formatter, the formatter must be
+            synchronized either on method or block level.
+
+            This rule has been deprecated in favor of the rule {% rule UnsynchronizedStaticFormatter %}.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    private static final SimpleDateFormat sdf = new SimpleDateFormat();
+    void bar() {
+        sdf.format(); // poor, no thread-safety
+    }
+    synchronized void foo() {
+        sdf.format(); // preferred
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UnsynchronizedStaticFormatter"
+          since="6.11.0"
+          message="Static Formatter objects should be accessed in a synchronized manner"
+          class="net.sourceforge.pmd.lang.java.rule.multithreading.UnsynchronizedStaticFormatterRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#unsynchronizedstaticformatter">
+        <description>
+            Instances of `java.text.Format` are generally not synchronized.
+            Sun recommends using separate format instances for each thread.
+            If multiple threads must access a static formatter, the formatter must be
+            synchronized either on method or block level.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    private static final SimpleDateFormat sdf = new SimpleDateFormat();
+    void bar() {
+        sdf.format(); // poor, no thread-safety
+    }
+    synchronized void foo() {
+        sdf.format(); // preferred
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UseConcurrentHashMap"
+          language="java"
+          minimumLanguageVersion="1.5"
+          since="4.2.6"
+          message="If you run in Java5 or newer and have concurrent access, you should use the ConcurrentHashMap implementation"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#useconcurrenthashmap">
+        <description>
+            Since Java5 brought a new implementation of the Map designed for multi-threaded access, you can
+            perform efficient map reads without blocking other threads.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//Type[../VariableDeclarator/VariableInitializer//AllocationExpression/ClassOrInterfaceType[@Image != 'ConcurrentHashMap']]
+/ReferenceType/ClassOrInterfaceType[@Image = 'Map']
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+public class ConcurrentApp {
+  public void getMyInstance() {
+    Map map1 = new HashMap();           // fine for single-threaded access
+    Map map2 = new ConcurrentHashMap(); // preferred for use with multiple threads
+
+    // the following case will be ignored by this rule
+    Map map3 = someModule.methodThatReturnMap(); // might be OK, if the returned map is already thread-safe
+  }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="UseNotifyAllInsteadOfNotify"
+          language="java"
+          since="3.0"
+          message="Call Thread.notifyAll() rather than Thread.notify()"
+          class="net.sourceforge.pmd.lang.rule.XPathRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_multithreading.html#usenotifyallinsteadofnotify">
+        <description>
+            Thread.notify() awakens a thread monitoring the object. If more than one thread is monitoring, then only
+            one is chosen.  The thread chosen is arbitrary; thus its usually safer to call notifyAll() instead.
+        </description>
+        <priority>3</priority>
+        <properties>
+            <property name="xpath">
+                <value>
+                    <![CDATA[
+//StatementExpression/PrimaryExpression
+[PrimarySuffix/Arguments[@ArgumentCount = '0']]
+[
+    PrimaryPrefix[
+        ./Name[@Image='notify' or ends-with(@Image,'.notify')]
+        or ../PrimarySuffix/@Image='notify'
+        or (./AllocationExpression and ../PrimarySuffix[@Image='notify'])
+    ]
+]
+]]>
+                </value>
+            </property>
+        </properties>
+        <example>
+            <![CDATA[
+  void bar() {
+    x.notify();
+    // If many threads are monitoring x, only one (and you won't know which) will be notified.
+    // use instead:
+    x.notifyAll();
+  }
+]]>
+        </example>
+    </rule>
+
+</ruleset>

config/pmd/category/java/security.xml

@@ -0,0 +1,65 @@
+<?xml version="1.0"?>
+
+<ruleset name="Security" xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
+
+    <description>
+        Rules that flag potential security flaws.
+    </description>
+
+    <rule name="HardCodedCryptoKey"
+          since="6.4.0"
+          message="Do not use hard coded encryption keys"
+          class="net.sourceforge.pmd.lang.java.rule.security.HardCodedCryptoKeyRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_security.html#hardcodedcryptokey">
+        <description>
+            Do not use hard coded values for cryptographic operations. Please store keys outside of source code.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    void good() {
+        SecretKeySpec secretKeySpec = new SecretKeySpec(Properties.getKey(), "AES");
+    }
+
+    void bad() {
+        SecretKeySpec secretKeySpec = new SecretKeySpec("my secret here".getBytes(), "AES");
+    }
+}
+]]>
+        </example>
+    </rule>
+
+    <rule name="InsecureCryptoIv"
+          since="6.3.0"
+          message="Do not use hard coded initialization vector in crypto operations"
+          class="net.sourceforge.pmd.lang.java.rule.security.InsecureCryptoIvRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_security.html#insecurecryptoiv">
+        <description>
+            Do not use hard coded initialization vector in cryptographic operations. Please use a randomly generated IV.
+        </description>
+        <priority>3</priority>
+        <example>
+            <![CDATA[
+public class Foo {
+    void good() {
+        SecureRandom random = new SecureRandom();
+        byte iv[] = new byte[16];
+        random.nextBytes(bytes);
+    }
+
+    void bad() {
+        byte[] iv = new byte[] { 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, 00, };
+    }
+
+    void alsoBad() {
+        byte[] iv = "secret iv in here".getBytes();
+    }
+}
+]]>
+        </example>
+    </rule>
+
+</ruleset>

gradle.properties

@@ -1,5 +1,5 @@
 group = org.xbib
 name = marc
-version = 2.14.1
+version = 2.9.21
 
 org.gradle.warning.mode = ALL

gradle/compile/java.gradle

@@ -2,12 +2,17 @@
 apply plugin: 'java-library'
 
 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(21)
-    }
     modularity.inferModulePath.set(true)
-    withSourcesJar()
-    withJavadocJar()
+}
+
+compileJava {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
+}
+
+compileTestJava {
+    sourceCompatibility = JavaVersion.VERSION_17
+    targetCompatibility = JavaVersion.VERSION_17
 }
 
 jar {
@@ -16,9 +21,23 @@ jar {
     }
 }
 
+task sourcesJar(type: Jar, dependsOn: classes) {
+    dependsOn classes
+    classifier 'sources'
+    from sourceSets.main.allSource
+}
+
+task javadocJar(type: Jar, dependsOn: javadoc) {
+    dependsOn javadoc
+    classifier 'javadoc'
+    from javadoc.destinationDir
+}
+
+artifacts {
+    archives sourcesJar, javadocJar
+}
+
 tasks.withType(JavaCompile) {
-    options.fork = true
-    options.forkOptions.jvmArgs += ['-Duser.language=en','-Duser.country=US']
     options.compilerArgs << '-Xlint:all'
     options.encoding = 'UTF-8'
 }

gradle/publish/forgejo.gradle

@@ -1,16 +0,0 @@
-if (project.hasProperty('forgeJoToken')) {
-    publishing {
-        repositories {
-            maven {
-                url 'https://xbib.org/api/packages/joerg/maven'
-                credentials(HttpHeaderCredentials) {
-                    name = "Authorization"
-                    value = "token ${project.property('forgeJoToken')}"
-                }
-                authentication {
-                    header(HttpHeaderAuthentication)
-                }
-            }
-        }
-    }
-}

gradle/publish/ivy.gradle

@@ -1,27 +0,0 @@
-apply plugin: 'ivy-publish'
-
-publishing {
-    repositories {
-        ivy {
-            url = "https://xbib.org/repo"
-        }
-    }
-    publications {
-        ivy(IvyPublication) {
-            from components.java
-            descriptor {
-                license {
-                    name = 'The Apache License, Version 2.0'
-                    url = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                }
-                author {
-                    name = 'Jörg Prante'
-                    url = 'http://example.com/users/jane'
-                }
-                descriptor.description {
-                    text = rootProject.ext.description
-                }
-            }
-        }
-    }
-}

gradle/publish/sonatype.gradle

@@ -1,12 +0,0 @@
-
-if (project.hasProperty('ossrhUsername') && project.hasProperty('ossrhPassword')) {
-    nexusPublishing {
-        repositories {
-            sonatype {
-                username = project.property('ossrhUsername')
-                password = project.property('ossrhPassword')
-                packageGroup = "org.xbib"
-            }
-        }
-    }
-}

gradle/publishing/publication.gradle

@@ -1,10 +1,13 @@
 
+apply plugin: "de.marcphilipp.nexus-publish"
+
 publishing {
     publications {
-        "${project.name}"(MavenPublication) {
+        mavenJava(MavenPublication) {
             from components.java
+            artifact sourcesJar
+            artifact javadocJar
             pom {
-                artifactId = project.name
                 name = project.name
                 description = rootProject.ext.description
                 url = rootProject.ext.url
@@ -19,7 +22,7 @@ publishing {
                         id = 'jprante'
                         name = 'Jörg Prante'
                         email = 'joergprante@gmail.com'
-                        url = 'https://xbib.org/joerg'
+                        url = 'https://github.com/jprante'
                     }
                 }
                 scm {
@@ -46,6 +49,17 @@ publishing {
 if (project.hasProperty("signing.keyId")) {
     apply plugin: 'signing'
     signing {
-        sign publishing.publications."${project.name}"
+        sign publishing.publications.mavenJava
+    }
+}
+if (project.hasProperty("ossrhUsername")) {
+    nexusPublishing {
+        repositories {
+            sonatype {
+                username = project.property('ossrhUsername')
+                password = project.property('ossrhPassword')
+                packageGroup = "org.xbib"
+            }
+        }
     }
 }

gradle/publishing/sonatype.gradle

@@ -0,0 +1,11 @@
+
+if (project.hasProperty('ossrhUsername') && project.hasProperty('ossrhPassword')) {
+
+    apply plugin: 'io.codearte.nexus-staging'
+
+    nexusStaging {
+        username = project.property('ossrhUsername')
+        password = project.property('ossrhPassword')
+        packageGroup = "org.xbib"
+    }
+}

gradle/test/junit5.gradle

@@ -1,10 +1,9 @@
 
 dependencies {
-    testImplementation testLibs.junit.jupiter.api
-    testImplementation testLibs.junit.jupiter.params
-    testImplementation testLibs.hamcrest
-    testRuntimeOnly testLibs.junit.jupiter.engine
-    testRuntimeOnly testLibs.junit.jupiter.platform.launcher
+    testImplementation libs.junit.jupiter.api
+    testImplementation libs.junit.jupiter.params
+    testImplementation libs.hamcrest
+    testRuntimeOnly libs.junit.jupiter.engine
 }
 
 test {
@@ -24,8 +23,4 @@ test {
     }
     jvmArgs '-Xmx2048m'
     systemProperty 'java.util.logging.config.file', 'src/test/resources/logging.properties'
-    // for reading large MARC XML files
-    systemProperty 'entityExpansionLimit', '2147480000'
-    systemProperty 'totalEntitySizeLimit', '2147480000'
-    systemProperty 'jdk.xml.totalEntitySizeLimit', '2147480000'
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,7 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-all.zip
-networkTimeout=10000
-validateDistributionUrl=true
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -55,7 +55,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,11 +80,13 @@ do
     esac
 done
 
-# This is normally unused
-# shellcheck disable=SC2034
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
 APP_BASE_NAME=${0##*/}
-# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
-APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -131,29 +133,22 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    if ! command -v java >/dev/null 2>&1
-    then
-        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
-    fi
 fi
 
 # Increase the maximum file descriptors if we can.
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
-        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
-        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -198,15 +193,11 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
-
-# Collect all arguments for the java command:
-#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
-#     and any embedded shellness will be escaped.
-#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
-#     treated as '${Hostname}' itself on the command line.
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \

gradlew.bat

@@ -26,7 +26,6 @@ if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
 if "%DIRNAME%"=="" set DIRNAME=.
-@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 

settings.gradle

@@ -15,21 +15,20 @@ pluginManagement {
 dependencyResolutionManagement {
     versionCatalogs {
         libs {
-            version('gradle', '8.5')
-        }
-        testLibs {
-            version('junit', '5.10.0')
+            version('gradle', '7.5.1')
+            version('groovy', '3.0.10')
+            version('junit', '5.9.1')
+            // all dependencies are test dependencies only
             library('junit-jupiter-api', 'org.junit.jupiter', 'junit-jupiter-api').versionRef('junit')
             library('junit-jupiter-params', 'org.junit.jupiter', 'junit-jupiter-params').versionRef('junit')
             library('junit-jupiter-engine', 'org.junit.jupiter', 'junit-jupiter-engine').versionRef('junit')
-            library('junit-jupiter-platform-launcher', 'org.junit.platform', 'junit-platform-launcher').version('1.10.0')
             library('hamcrest', 'org.hamcrest', 'hamcrest-library').version('2.2')
             library('charactersets', 'org.xbib', 'bibliographic-character-sets').version('2.0.0')
+            library('json', 'org.xbib', 'content-json').version('5.0.1')
             library('xalan', 'xalan', 'xalan').version('2.7.2')
             library('xmlunit', 'org.xmlunit', 'xmlunit-matchers').version('2.8.4')
             library('mockito', 'org.mockito', 'mockito-core').version('3.3.3')
             library('marc4j', 'org.marc4j', 'marc4j').version('2.9.2')
-            library('json', 'org.xbib', 'datastructures-json-tiny').version('5.0.6')
         }
     }
 }

src/main/java/org/xbib/marc/MarcField.java

@@ -15,7 +15,6 @@
  */
 package org.xbib.marc;
 
-import java.util.Objects;
 import org.xbib.marc.dialects.mab.MabSubfieldControl;
 import org.xbib.marc.label.RecordLabel;
 
@@ -25,7 +24,6 @@ import java.util.Deque;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.function.BinaryOperator;
 import java.util.function.Supplier;
 import java.util.regex.Pattern;
@@ -604,37 +602,6 @@ public class MarcField implements Comparable<MarcField> {
             return this;
         }
 
-        /**
-         * Remove subfields if they match the given set of subfield IDs.
-         * @param subfieldIds the IDs to remove
-         * @return this builder
-         */
-        public Builder removeSubfields(Set<String> subfieldIds) {
-            // create a new subfield list and replace the whole list by a filtered list
-            LinkedList<Subfield> list = subfields.stream()
-                    .filter(sf -> !subfieldIds.contains(sf.id))
-                    .collect(Collectors.toCollection(LinkedList::new));
-            this.subfields.clear();
-            this.subfields.addAll(list);
-            return this;
-        }
-
-        /**
-         * In-place replacement of all subfields with a given ID.
-         * @param subfieldId the subfield ID
-         * @param newValue the new value, must be non-null
-         * @return this builder
-         */
-        public Builder replace(String subfieldId, String newValue) {
-            Objects.requireNonNull(newValue);
-            for (Subfield subfield : subfields) {
-                if (subfield.getId().equals(subfieldId)) {
-                    subfield.setValue(newValue);
-                }
-            }
-            return this;
-        }
-
         /**
          * Copy a MARC field into this builder.
          * @param field the MARC field to copy
@@ -803,7 +770,7 @@ public class MarcField implements Comparable<MarcField> {
 
         private final String id;
 
-        private String value;
+        private final String value;
 
         private Subfield(String id, String value) {
             this.id = id;
@@ -826,20 +793,6 @@ public class MarcField implements Comparable<MarcField> {
             return value;
         }
 
-        private void setValue(String value) {
-            this.value = value;
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            return obj instanceof Subfield && toString().equals(obj.toString());
-        }
-
-        @Override
-        public int hashCode() {
-            return toString().hashCode();
-        }
-
         @Override
         public String toString() {
             return id + "=" + value;

src/main/java/org/xbib/marc/MarcFieldDirectory.java

@@ -20,7 +20,7 @@ import org.xbib.marc.label.RecordLabel;
 import java.io.IOException;
 import java.util.TreeMap;
 
-@SuppressWarnings({"serial", "this-escape"})
+@SuppressWarnings("serial")
 public class MarcFieldDirectory extends TreeMap<Integer, MarcField.Builder> {
 
     public MarcFieldDirectory(RecordLabel label, String encodedDirectory) throws IOException {

src/main/java/org/xbib/marc/MarcRecord.java

@@ -67,7 +67,7 @@ public class MarcRecord implements Map<String, Object> {
 
     private transient RecordLabel recordLabel;
 
-    private transient Collection<MarcField> marcFields;
+    private transient List<MarcField> marcFields;
 
     private MarcRecord(Map<String, Object> delegate) {
         this.delegate = delegate;
@@ -86,7 +86,7 @@ public class MarcRecord implements Map<String, Object> {
     public MarcRecord(String format,
                       String type,
                       RecordLabel recordLabel,
-                      Collection<MarcField> marcFields,
+                      List<MarcField> marcFields,
                       boolean lightweight,
                       Comparator<String> comparator) {
         this.format = format;
@@ -183,7 +183,7 @@ public class MarcRecord implements Map<String, Object> {
      *
      * @return the MARC field list
      */
-    public Collection<MarcField> getFields() {
+    public List<MarcField> getFields() {
         return marcFields;
     }
 

src/main/java/org/xbib/marc/dialects/mab/xml/MabXMLContentHandler.java

@@ -33,7 +33,6 @@ public class MabXMLContentHandler extends MarcContentHandler implements MabXMLCo
 
     private final Set<String> validNamespaces = new HashSet<>(Collections.singletonList(MABXML_NAMESPACE));
 
-    @SuppressWarnings("this-escape")
     public MabXMLContentHandler() {
         setTrim(true);
     }

src/main/java/org/xbib/marc/io/ScanBuffer.java

@@ -18,16 +18,15 @@ package org.xbib.marc.io;
 /**
  * Scan buffer.
  */
-@SuppressWarnings("this-escape")
 public class ScanBuffer {
 
     private boolean cs;
 
-    private char[] buffer;
+    private char[] buffer = new char[0];
 
-    private int[] buffer2;
+    private int[] buffer2 = new int[0];
 
-    private char[] token;
+    private char[] token = new char[0];
 
     private int pos;
 

src/main/java/org/xbib/marc/json/MarcListNode.java

@@ -3,7 +3,6 @@ package org.xbib.marc.json;
 import java.util.LinkedList;
 import java.util.List;
 
-@SuppressWarnings("serial")
 public class MarcListNode extends LinkedList<Node<?>> implements ListNode {
 
     public MarcListNode() {

src/main/java/org/xbib/marc/json/MarcMapNode.java

@@ -3,7 +3,6 @@ package org.xbib.marc.json;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
-@SuppressWarnings("serial")
 public class MarcMapNode extends LinkedHashMap<CharSequence, Node<?>> implements MapNode {
 
     public MarcMapNode() {

src/main/java/org/xbib/marc/json/ValueNode.java

@@ -8,6 +8,11 @@ public class ValueNode implements Node<Object> {
         this.value = value;
     }
 
+    @Override
+    public int getDepth() {
+        return 0;
+    }
+
     public void set(Object value) {
         this.value = value;
     }

src/main/java/org/xbib/marc/tools/MarcTool.java

@@ -22,7 +22,7 @@ import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.stream.StreamResult;
 import java.io.BufferedInputStream;
 import java.io.InputStream;
-import java.net.URI;
+import java.net.URL;
 import java.nio.charset.Charset;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -120,7 +120,7 @@ public class MarcTool {
                 if (schema != null && stylesheet != null && result != null) {
                     System.setProperty("http.agent", "Java Agent");
                     builder.setSchema(schema).build().transform(TransformerFactory.newInstance(),
-                            URI.create(stylesheet).toURL(),
+                            new URL(stylesheet),
                             new StreamResult(Files.newBufferedWriter(Paths.get(result))));
                 } else {
                     builder.build().writeCollection(65536);

src/main/java/org/xbib/marc/xml/MarcXchangeWriter.java

@@ -60,7 +60,6 @@ import java.util.zip.GZIPOutputStream;
  * This MarcXchange Writer writes MarcXchange events to a StaX XML output stream or XML event consumer.
  * Default output format is MarcXchange.
  */
-@SuppressWarnings("this-escape")
 public class MarcXchangeWriter extends MarcContentHandler implements Flushable, Closeable {
 
     private static final Logger logger = Logger.getLogger(MarcXchangeWriter.class.getName());

src/test/java/org/xbib/marc/MarcRecordTest.java

@@ -22,8 +22,8 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import java.io.IOException;
 import java.time.LocalDate;
 import org.junit.jupiter.api.Test;
-import org.xbib.datastructures.api.Builder;
-import org.xbib.datastructures.json.tiny.JsonBuilder;
+import org.xbib.content.XContentBuilder;
+import org.xbib.content.json.JsonXContent;
 import org.xbib.marc.label.RecordLabel;
 import org.xbib.marc.transformer.value.MarcValueTransformers;
 import org.xbib.marc.xml.MarcXchangeWriter;
@@ -295,9 +295,9 @@ public class MarcRecordTest {
                 "100", Map.of("_", Map.of("a", "Hello World"))));
         MarcRecord marcRecord = MarcRecord.from(map);
         assertEquals("{001=123, 100={_={a=Hello World}}}", marcRecord.toString());
-        Builder builder = JsonBuilder.builder();
-        builder.buildMap(marcRecord);
-        assertEquals("{\"001\":\"123\",\"100\":{\"_\":{\"a\":\"Hello World\"}}}", builder.build());
+        XContentBuilder builder = JsonXContent.contentBuilder();
+        builder.map(marcRecord);
+        assertEquals("{\"001\":\"123\",\"100\":{\"_\":{\"a\":\"Hello World\"}}}", builder.string());
     }
 
     @Test
@@ -308,9 +308,4 @@ public class MarcRecordTest {
         marcRecord.all("001", field -> assertEquals("123", field.getValue()));
         marcRecord.all("100", field -> assertEquals("Hello World", field.getFirstSubfieldValue("a")));
     }
-
-    @Test
-    public void testMarcRecordBuildWithUniqueFields() {
-
-    }
 }

src/test/java/org/xbib/marc/filter/MarcFieldFilterByRecordIdentifierTest.java

@@ -16,8 +16,8 @@
 package org.xbib.marc.filter;
 
 import org.junit.jupiter.api.Test;
-import org.xbib.datastructures.api.Builder;
-import org.xbib.datastructures.json.tiny.JsonBuilder;
+import org.xbib.content.XContentBuilder;
+import org.xbib.content.json.JsonXContent;
 import org.xbib.marc.Marc;
 import org.xbib.marc.MarcField;
 import org.xbib.marc.MarcFieldAdapter;
@@ -93,15 +93,15 @@ public class MarcFieldFilterByRecordIdentifierTest {
                 .collect(Collectors.toList());
 
         // JSON output
-        Builder builder = JsonBuilder.builder()
-                .beginMap();
+        XContentBuilder builder = JsonXContent.contentBuilder().prettyPrint()
+                .startObject();
         for (Map.Entry<String, Map<String, List<Map<String, String>>>> entry : result.entrySet()) {
             builder.field(entry.getKey(), entry.getValue());
         }
         builder.field("issns", issns);
-        builder.endMap();
+        builder.endObject();
 
-        logger.log(Level.INFO, builder.build());
+        logger.log(Level.INFO, builder.string());
     }
 
     private static boolean matchISSNField(MarcField field, MarcField.Subfield subfield) {

src/test/java/org/xbib/marc/filter/MarcFieldFilterTest.java

@@ -15,9 +15,9 @@
  */
 package org.xbib.marc.filter;
 
+import static org.xbib.content.json.JsonXContent.contentBuilder;
 import org.junit.jupiter.api.Test;
-import org.xbib.datastructures.api.Builder;
-import org.xbib.datastructures.json.tiny.JsonBuilder;
+import org.xbib.content.XContentBuilder;
 import org.xbib.marc.Marc;
 import org.xbib.marc.MarcField;
 import org.xbib.marc.MarcFieldAdapter;
@@ -77,15 +77,15 @@ public class MarcFieldFilterTest {
                 .collect(Collectors.toList());
 
         // JSON output
-        Builder builder = JsonBuilder.builder()
-                .beginMap();
+        XContentBuilder builder = contentBuilder().prettyPrint()
+                .startObject();
         for (Map.Entry<String, List<Map<String, String>>> entry : result.entrySet()) {
             builder.field(entry.getKey(), entry.getValue());
         }
-        builder.collection("issns", issns);
-        builder.endMap();
+        builder.array("issns", issns);
+        builder.endObject();
 
-        logger.log(Level.INFO, builder.build());
+        logger.log(Level.INFO, builder.string());
     }
 
     private static boolean matchISSNField(MarcField field, MarcField.Subfield subfield) {