diff --git a/build.gradle b/build.gradle
index fbd45cb..9bacf0f 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,33 +1,10 @@
 plugins {
+    id "com.github.spotbugs" version "2.0.0"
     id "org.sonarqube" version '2.6.1'
     id "io.codearte.nexus-staging" version "0.11.0"
     id "org.xbib.gradle.plugin.asciidoctor" version "1.5.6.0.1"
 }
 
-printf "Host: %s\nOS: %s %s %s\nJVM: %s %s %s %s\nGradle: %s Groovy: %s Java: %s\n" +
-        "Build: group: ${project.group} name: ${project.name} version: ${project.version}\n",
-        InetAddress.getLocalHost(),
-        System.getProperty("os.name"),
-        System.getProperty("os.arch"),
-        System.getProperty("os.version"),
-        System.getProperty("java.version"),
-        System.getProperty("java.vm.version"),
-        System.getProperty("java.vm.vendor"),
-        System.getProperty("java.vm.name"),
-        gradle.gradleVersion,
-        GroovySystem.getVersion(),
-        JavaVersion.current()
-
-apply plugin: 'java'
-apply plugin: 'org.xbib.gradle.plugin.asciidoctor'
-
-configurations {
-    asciidoclet
-}
-
-dependencies {
-    asciidoclet "org.asciidoctor:asciidoclet:${project.property('asciidoclet.version')}"
-}
 
 asciidoctor {
     backends 'html5'
@@ -40,7 +17,7 @@ asciidoctor {
             stylesheet: "${projectDir}/src/docs/asciidoc/css/foundation.css"
 }
 
-javadoc {
+/*javadoc {
     options.docletpath = configurations.asciidoclet.files.asType(List)
     options.doclet = 'org.asciidoctor.Asciidoclet'
     options.overview = "${rootProject.projectDir}/src/docs/asciidoclet/overview.adoc"
@@ -51,42 +28,54 @@ javadoc {
     configure(options) {
         noTimestamp = true
     }
-}
+}*/
 
 subprojects {
     apply plugin: 'java'
     apply plugin: 'maven'
-    apply plugin: 'signing'
-    apply plugin: 'findbugs'
     apply plugin: 'pmd'
     apply plugin: 'checkstyle'
-    apply plugin: 'jacoco'
-
-    repositories {
-        mavenCentral()
-    }
-
-    configurations {
-        wagon
-    }
+    apply plugin: "com.github.spotbugs"
 
     dependencies {
-        testCompile "junit:junit:${project.property('junit.version')}"
-        wagon "org.apache.maven.wagon:wagon-ssh:${project.property('wagon.version')}"
+        testImplementation "org.junit.jupiter:junit-jupiter-api:${project.property('junit.version')}"
+        testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${project.property('junit.version')}"
+        testImplementation "org.xbib:bibliographic-character-sets:${project.property('xbib-bibliographic-character-sets.version')}"
     }
 
-    sourceCompatibility = JavaVersion.VERSION_1_8
-    targetCompatibility = JavaVersion.VERSION_1_8
+    compileJava {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+
+    compileTestJava {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
 
-    [compileJava, compileTestJava]*.options*.encoding = 'UTF-8'
     tasks.withType(JavaCompile) {
-        options.compilerArgs << "-Xlint:all,-fallthrough" << "-profile" << "compact1"
+        options.compilerArgs << "-Xlint:all,-fallthrough"
+    }
+
+    clean {
+        delete 'out'
     }
 
     test {
+        useJUnitPlatform()
+        systemProperty 'java.util.logging.config.file', project.file('src/test/resources/logging.properties')
+        failFast = false
         testLogging {
-            showStandardStreams = false
-            exceptionFormat = 'full'
+            events 'STARTED', 'PASSED', 'FAILED', 'SKIPPED'
+        }
+        afterSuite { desc, result ->
+            if (!desc.parent) {
+                println "\nTest result: ${result.resultType}"
+                println "Test summary: ${result.testCount} tests, " +
+                        "${result.successfulTestCount} succeeded, " +
+                        "${result.failedTestCount} failed, " +
+                        "${result.skippedTestCount} skipped"
+            }
         }
     }
 
@@ -103,13 +92,124 @@ subprojects {
         archives sourcesJar, javadocJar
     }
 
-    if (project.hasProperty('signing.keyId')) {
-        signing {
-            sign configurations.archives
+    ext {
+        user = 'xbib'
+        projectName = 'cql'
+        projectDescription = 'Contextual Query Language compiler for Java'
+        scmUrl = 'https://github.com/xbib/cql'
+        scmConnection = 'scm:git:git://github.com/xbib/cql.git'
+        scmDeveloperConnection = 'scm:git:git://github.com/xbib/cql.git'
+    }
+
+    spotbugs {
+        toolVersion = '3.1.12'
+        sourceSets = [sourceSets.main]
+        ignoreFailures = true
+        effort = "max"
+        reportLevel = "high"
+    }
+
+    spotbugsMain.reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+
+    spotbugsTest.reports {
+        xml.enabled = false
+        html.enabled = true
+    }
+
+    tasks.withType(Pmd) {
+        ignoreFailures = true
+        reports {
+            xml.enabled = true
+            html.enabled = true
         }
     }
 
-    apply from: "${rootProject.projectDir}/gradle/ext.gradle"
-    apply from: "${rootProject.projectDir}/gradle/publish.gradle"
-    apply from: "${rootProject.projectDir}/gradle/sonarqube.gradle"
+    tasks.withType(Checkstyle) {
+        ignoreFailures = true
+        reports {
+            xml.enabled = true
+            html.enabled = true
+        }
+    }
+
+    pmd {
+        toolVersion = '6.11.0'
+        ruleSets = ['category/java/bestpractices.xml']
+    }
+
+    checkstyle {
+        configFile = rootProject.file('config/checkstyle/checkstyle.xml')
+        ignoreFailures = true
+        showViolations = true
+    }
+
+    sonarqube {
+        properties {
+            property "sonar.projectName", "${project.group} ${project.name}"
+            property "sonar.sourceEncoding", "UTF-8"
+            property "sonar.tests", "src/test/java"
+            property "sonar.scm.provider", "git"
+            property "sonar.junit.reportsPath", "build/test-results/test/"
+        }
+    }
+
+    task sonatypeUpload(type: Upload, dependsOn: build) {
+        group = 'publish'
+        configuration = configurations.archives
+        uploadDescriptor = true
+        repositories {
+            if (project.hasProperty('ossrhUsername')) {
+                mavenDeployer {
+                    beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
+                    repository(url: uri(ossrhReleaseUrl)) {
+                        authentication(userName: ossrhUsername, password: ossrhPassword)
+                    }
+                    snapshotRepository(url: uri(ossrhSnapshotUrl)) {
+                        authentication(userName: ossrhUsername, password: ossrhPassword)
+                    }
+                    pom.project {
+                        groupId project.group
+                        artifactId project.name
+                        version project.version
+                        name project.name
+                        description projectDescription
+                        packaging 'jar'
+                        inceptionYear '2016'
+                        url scmUrl
+                        organization {
+                            name 'xbib'
+                            url 'http://xbib.org'
+                        }
+                        developers {
+                            developer {
+                                id user
+                                name 'Jörg Prante'
+                                email 'joergprante@gmail.com'
+                                url 'https://github.com/jprante'
+                            }
+                        }
+                        scm {
+                            url scmUrl
+                            connection scmConnection
+                            developerConnection scmDeveloperConnection
+                        }
+                        licenses {
+                            license {
+                                name 'The Apache License, Version 2.0'
+                                url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    nexusStaging {
+        packageGroup = "org.xbib"
+    }
+
 }
diff --git a/config/checkstyle/checkstyle.xml b/config/checkstyle/checkstyle.xml
index 42d1e17..20fd3f0 100644
--- a/config/checkstyle/checkstyle.xml
+++ b/config/checkstyle/checkstyle.xml
@@ -10,7 +10,7 @@ page at http://checkstyle.sourceforge.net/config.html -->
 <module name="Checker">
 
     <module name="SuppressionFilter">
-        <property name="file" value="config/checkstyle/suppressions.xml"/>
+        <property name="file" value="${config_loc}/suppressions.xml"/>
     </module>
 
     <module name="FileTabCharacter">
diff --git a/cql-common/src/main/java/org/xbib/cql/util/QueryStringDecoder.java b/cql-common/src/main/java/org/xbib/cql/util/QueryStringDecoder.java
index be264a6..fb8dac1 100644
--- a/cql-common/src/main/java/org/xbib/cql/util/QueryStringDecoder.java
+++ b/cql-common/src/main/java/org/xbib/cql/util/QueryStringDecoder.java
@@ -21,7 +21,7 @@ import java.util.Map;
  * assert decoder.getParameters().get("y").get(0).equals("2");
  * </pre>
  * This decoder can also decode the content of an HTTP POST request whose
- * content type is <tt>application/x-www-form-urlencoded</tt>:
+ * content type is {@code application/x-www-form-urlencoded}:
  * <pre>
  * {@link QueryStringDecoder} decoder = new {@link QueryStringDecoder}("recipient=world&amp;x=1;y=2", false);
  * </pre>
diff --git a/cql-common/src/test/java/org/xbib/cql/QueryTest.java b/cql-common/src/test/java/org/xbib/cql/QueryTest.java
index db580ff..93ed067 100644
--- a/cql-common/src/test/java/org/xbib/cql/QueryTest.java
+++ b/cql-common/src/test/java/org/xbib/cql/QueryTest.java
@@ -1,20 +1,21 @@
 package org.xbib.cql;
 
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.LineNumberReader;
 import java.nio.charset.StandardCharsets;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  *
  */
-public class QueryTest extends Assert {
+class QueryTest {
 
     @Test
-    public void testValidQueries() throws IOException {
+    void testValidQueries() throws IOException {
         test("queries.txt");
     }
 
diff --git a/cql-common/src/test/java/org/xbib/cql/util/QuotedStringTokenizerTest.java b/cql-common/src/test/java/org/xbib/cql/util/QuotedStringTokenizerTest.java
index 940bcfa..6992532 100644
--- a/cql-common/src/test/java/org/xbib/cql/util/QuotedStringTokenizerTest.java
+++ b/cql-common/src/test/java/org/xbib/cql/util/QuotedStringTokenizerTest.java
@@ -1,16 +1,16 @@
 package org.xbib.cql.util;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.jupiter.api.Test;
 
-import org.junit.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  *
  */
-public class QuotedStringTokenizerTest {
+class QuotedStringTokenizerTest {
 
     @Test
-    public void testTokenizer() throws Exception {
+    void testTokenizer() throws Exception {
         String s = "Linux is \"pinguin's best friend\", not Windows";
         QuotedStringTokenizer tokenizer = new QuotedStringTokenizer(s);
         assertEquals("Linux", tokenizer.nextToken());
diff --git a/cql-elasticsearch/src/test/java/org/xbib/cql/elasticsearch/ElasticsearchQueryTest.java b/cql-elasticsearch/src/test/java/org/xbib/cql/elasticsearch/ElasticsearchQueryTest.java
index bb5eed0..7f04101 100644
--- a/cql-elasticsearch/src/test/java/org/xbib/cql/elasticsearch/ElasticsearchQueryTest.java
+++ b/cql-elasticsearch/src/test/java/org/xbib/cql/elasticsearch/ElasticsearchQueryTest.java
@@ -1,7 +1,6 @@
 package org.xbib.cql.elasticsearch;
 
-import org.junit.Assert;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 import org.xbib.cql.CQLParser;
 
 import java.io.IOException;
@@ -9,18 +8,20 @@ import java.io.InputStreamReader;
 import java.io.LineNumberReader;
 import java.nio.charset.StandardCharsets;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  *
  */
-public class ElasticsearchQueryTest extends Assert {
+class ElasticsearchQueryTest {
 
     @Test
-    public void testValidQueries() throws IOException {
+    void testValidQueries() throws IOException {
         test("queries.txt");
     }
 
     @Test
-    public void testSimpleTermFilter() throws Exception {
+    void testSimpleTermFilter() throws Exception {
         String cql = "Jörg";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
@@ -31,7 +32,7 @@ public class ElasticsearchQueryTest extends Assert {
     }
 
     @Test
-    public void testFieldTermFilter() throws Exception {
+    void testFieldTermFilter() throws Exception {
         String cql = "dc.type = electronic";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
@@ -42,7 +43,7 @@ public class ElasticsearchQueryTest extends Assert {
     }
 
     @Test
-    public void testDoubleFieldTermFilter() throws Exception {
+    void testDoubleFieldTermFilter() throws Exception {
         String cql = "dc.type = electronic and dc.date = 2013";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
@@ -56,7 +57,7 @@ public class ElasticsearchQueryTest extends Assert {
     }
 
     @Test
-    public void testTripleFieldTermFilter() throws Exception {
+    void testTripleFieldTermFilter() throws Exception {
         String cql = "dc.format = online and dc.type = electronic and dc.date = 2013";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
@@ -70,7 +71,7 @@ public class ElasticsearchQueryTest extends Assert {
     }
 
     @Test
-    public void testBoost() throws Exception {
+    void testBoost() throws Exception {
         String cql = "Jörg";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
@@ -87,7 +88,7 @@ public class ElasticsearchQueryTest extends Assert {
     }
 
     @Test
-    public void testWildcardTerm() throws Exception {
+    void testWildcardTerm() throws Exception {
         String cql = "dc.format = book*";
         CQLParser parser = new CQLParser(cql);
         parser.parse();
diff --git a/gradle.properties b/gradle.properties
index 47aedc0..97acf7a 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,8 +1,8 @@
 group = org.xbib
 name = cql
-version = 1.2.0
+version = 2.0.0
 
-xbib-content.version = 1.3.0
-junit.version = 4.12
-wagon.version = 3.0.0
-asciidoclet.version = 1.5.4
+xbib-content.version = 2.0.0
+xbib-bibliographic-character-sets.version = 1.0.0
+
+junit.version = 5.5.1
diff --git a/gradle/ext.gradle b/gradle/ext.gradle
deleted file mode 100644
index 9b3403e..0000000
--- a/gradle/ext.gradle
+++ /dev/null
@@ -1,8 +0,0 @@
-ext {
-    user = 'xbib'
-    projectName = 'cql'
-    projectDescription = 'Contextual Query Language compiler for Java'
-    scmUrl = 'https://github.com/xbib/cql'
-    scmConnection = 'scm:git:git://github.com/xbib/cql.git'
-    scmDeveloperConnection = 'scm:git:git://github.com/xbib/cql.git'
-}
diff --git a/gradle/publish.gradle b/gradle/publish.gradle
deleted file mode 100644
index b6678b6..0000000
--- a/gradle/publish.gradle
+++ /dev/null
@@ -1,104 +0,0 @@
-
-task xbibUpload(type: Upload, dependsOn: build) {
-    group = 'publish'
-    configuration = configurations.archives
-    uploadDescriptor = true
-    repositories {
-        if (project.hasProperty('xbibUsername')) {
-            mavenDeployer {
-                configuration = configurations.wagon
-                repository(url: uri('sftp://xbib.org/repository')) {
-                        authentication(userName: xbibUsername, privateKey: xbibPrivateKey)
-                }
-                pom.project {
-                    groupId project.group
-                    artifactId project.name
-                    version project.version
-                    name project.name
-                    description projectDescription
-                    packaging 'jar'
-                    inceptionYear '2016'
-                    url scmUrl
-                    organization {
-                        name 'xbib'
-                        url 'http://xbib.org'
-                    }
-                    developers {
-                        developer {
-                            id user
-                            name 'Jörg Prante'
-                            email 'joergprante@gmail.com'
-                            url 'https://github.com/jprante'
-                        }
-                    }
-                    scm {
-                        url scmUrl
-                        connection scmConnection
-                        developerConnection scmDeveloperConnection
-                    }
-                    licenses {
-                        license {
-                            name 'The Apache License, Version 2.0'
-                            url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                        }
-                    }
-                }            }
-        }
-    }
-}
-
-task sonatypeUpload(type: Upload, dependsOn: build) {
-    group = 'publish'
-    configuration = configurations.archives
-    uploadDescriptor = true
-    repositories {
-        if (project.hasProperty('ossrhUsername')) {
-            mavenDeployer {
-                beforeDeployment { MavenDeployment deployment -> signing.signPom(deployment) }
-                repository(url: uri(ossrhReleaseUrl)) {
-                        authentication(userName: ossrhUsername, password: ossrhPassword)
-                }
-                snapshotRepository(url: uri(ossrhSnapshotUrl)) {
-                        authentication(userName: ossrhUsername, password: ossrhPassword)
-                }
-                pom.project {
-                    groupId project.group
-                    artifactId project.name
-                    version project.version
-                    name project.name
-                    description projectDescription
-                    packaging 'jar'
-                    inceptionYear '2016'
-                    url scmUrl
-                    organization {
-                        name 'xbib'
-                        url 'http://xbib.org'
-                    }
-                    developers {
-                        developer {
-                            id user
-                            name 'Jörg Prante'
-                            email 'joergprante@gmail.com'
-                            url 'https://github.com/jprante'
-                        }
-                    }
-                    scm {
-                        url scmUrl
-                        connection scmConnection
-                        developerConnection scmDeveloperConnection
-                    }
-                    licenses {
-                        license {
-                            name 'The Apache License, Version 2.0'
-                            url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                        }
-                    }
-                }
-            }
-        }
-    }
-}
-
-nexusStaging {
-    packageGroup = "org.xbib"
-}
diff --git a/gradle/sonarqube.gradle b/gradle/sonarqube.gradle
deleted file mode 100644
index a5e21a3..0000000
--- a/gradle/sonarqube.gradle
+++ /dev/null
@@ -1,40 +0,0 @@
-
-tasks.withType(FindBugs) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = false
-        html.enabled = true
-    }
-}
-tasks.withType(Pmd) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = true
-        html.enabled = true
-    }
-}
-tasks.withType(Checkstyle) {
-    ignoreFailures = true
-    reports {
-        xml.enabled = true
-        html.enabled = true
-    }
-}
-
-jacocoTestReport {
-    reports {
-        xml.enabled = true
-        csv.enabled = false
-    }
-}
-
-sonarqube {
-    properties {
-        property "sonar.projectName", "${project.group} ${project.name}"
-        property "sonar.sourceEncoding", "UTF-8"
-        property "sonar.tests", "src/test/java"
-        property "sonar.scm.provider", "git"
-        property "sonar.java.coveragePlugin", "jacoco"
-        property "sonar.junit.reportsPath", "build/test-results/test/"
-    }
-}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index c44b679..5c2d1cf 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 20572e7..9a71a62 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
-#Thu Feb 08 11:11:10 CET 2018
+#Mon Aug 12 10:55:55 CEST 2019
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.3.1-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.5.1-all.zip
+zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index cccdd3d..b0d6d0a 100755
--- a/gradlew
+++ b/gradlew
@@ -1,5 +1,21 @@
 #!/usr/bin/env sh
 
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
 ##############################################################################
 ##
 ##  Gradle start up script for UN*X
@@ -28,7 +44,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=`basename "$0"`
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
diff --git a/gradlew.bat b/gradlew.bat
index e95643d..15e1ee3 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -1,3 +1,19 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      http://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
 @if "%DEBUG%" == "" @echo off
 @rem ##########################################################################
 @rem
@@ -14,7 +30,7 @@ set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 
 @rem Find java.exe
 if defined JAVA_HOME goto findJavaFromJavaHome