adding config loader

content-config/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+    api project(':content-yaml')
+}

content-config/src/main/java/module-info.java

@@ -0,0 +1,4 @@
+module org.xbib.content.config {
+    exports org.xbib.content.config;
+    requires transitive org.xbib.content.yaml;
+}

content-config/src/main/java/org/xbib/content/config/ConfigLoader.java

@@ -0,0 +1,130 @@
+package org.xbib.content.config;
+
+import org.xbib.content.json.JsonSettingsLoader;
+import org.xbib.content.settings.Settings;
+import org.xbib.content.settings.SettingsLoader;
+import org.xbib.content.yaml.YamlSettingsLoader;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+/**
+ * A configuration file loader for JSON/YAML configuration files.
+ */
+public class ConfigLoader {
+
+    private static final String JSON = ".json";
+
+    private static final String YML = ".yml";
+
+    private static final String YAML = ".yaml";
+
+    private final ConfigLogger logger;
+
+    public ConfigLoader(ConfigLogger logger) {
+        this.logger = logger;
+    }
+
+    public Settings.Builder loadSettings(ClassLoader classLoader,
+                                         String applicationName,
+                                         String... fileNamesWithoutSuffix) throws IOException {
+        for (String fileNameWithoutSuffix : fileNamesWithoutSuffix) {
+            Settings.Builder settings = createSettingsFromFile(createListOfLocations(applicationName, fileNameWithoutSuffix));
+            if (settings != null) {
+                return settings;
+            }
+            settings = createClasspathSettings(classLoader, applicationName, fileNameWithoutSuffix);
+            if (settings != null) {
+                return settings;
+            }
+            settings = createClasspathSettings(ConfigLoader.class.getClassLoader(), applicationName, fileNameWithoutSuffix);
+            if (settings != null) {
+                return settings;
+            }
+            settings = createClasspathSettings(ClassLoader.getSystemClassLoader(), applicationName, fileNameWithoutSuffix);
+            if (settings != null) {
+                return settings;
+            }
+        }
+        throw new IllegalArgumentException("no config found for " + applicationName + " "+ Arrays.asList(fileNamesWithoutSuffix));
+    }
+
+    private Settings.Builder createClasspathSettings(ClassLoader classLoader, String applicationName, String fileNameWithoutSuffix)
+            throws IOException {
+        for (String suffix : List.of(YML, YAML, JSON)) {
+            InputStream inputStream = classLoader.getResourceAsStream(applicationName + '-' + fileNameWithoutSuffix + suffix);
+            if (inputStream != null) {
+                logger.info("found resource: " + applicationName + '-' + fileNameWithoutSuffix + suffix);
+                Settings.Builder settings = createSettingsFromStream(inputStream, suffix);
+                if (settings != null) {
+                    return settings;
+                }
+            }
+        }
+        return null;
+    }
+
+    private Settings.Builder createSettingsFromFile(List<String> settingsFileNames) throws IOException {
+        for (String settingsFileName: settingsFileNames) {
+            int pos = settingsFileName.lastIndexOf('.');
+            String suffix = (pos > 0 ? settingsFileName.substring(pos) : "").toLowerCase(Locale.ROOT);
+            Path path = Paths.get(settingsFileName);
+            logger.info("trying " + path.toString());
+            if (Files.exists(path)) {
+                logger.info("found path: " + path);
+                return createSettingsFromStream(Files.newInputStream(path), suffix);
+            }
+        }
+        return null;
+    }
+
+    private Settings.Builder createSettingsFromStream(InputStream inputStream, String suffix) throws IOException {
+        if (inputStream == null) {
+            logger.error("unable to open input stream");
+            return null;
+        }
+        SettingsLoader settingsLoader = isYaml(suffix) ? new YamlSettingsLoader() :
+                isJson(suffix) ? new JsonSettingsLoader() : null;
+        if (settingsLoader != null) {
+            Settings.Builder settings;
+            try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
+                String content = reader.lines().collect(Collectors.joining("\n"));
+                settings = Settings.settingsBuilder().put(settingsLoader.load(content));
+            }
+            return settings;
+        } else {
+            logger.error("suffix is invalid: " + suffix);
+        }
+        return null;
+    }
+
+    private static List<String> createListOfLocations(String applicationName, String fileNameWithoutSuffix) {
+        return List.of(
+                applicationName + '-' + fileNameWithoutSuffix + YML,
+                applicationName + '-' + fileNameWithoutSuffix + YAML,
+                applicationName + '-' + fileNameWithoutSuffix + JSON,
+                System.getProperty("user.home") + "/." + applicationName + '/' + fileNameWithoutSuffix + YML,
+                System.getProperty("user.home") + "/." + applicationName + '/' + fileNameWithoutSuffix + YAML,
+                System.getProperty("user.home") + "/." + applicationName + '/' + fileNameWithoutSuffix + JSON,
+                "/etc/" + applicationName + '/' + fileNameWithoutSuffix + YML,
+                "/etc/" + applicationName + '/' + fileNameWithoutSuffix + YAML,
+                "/etc/" + applicationName + '/' + fileNameWithoutSuffix + JSON);
+    }
+
+    private static boolean isYaml(String suffix) {
+        return YAML.equals(suffix) || YML.equals(suffix);
+    }
+
+    private static boolean isJson(String suffix) {
+        return JSON.equals(suffix);
+    }
+}

content-config/src/main/java/org/xbib/content/config/ConfigLogger.java

@@ -0,0 +1,18 @@
+package org.xbib.content.config;
+
+import java.io.OutputStream;
+
+public interface ConfigLogger {
+
+    void setLevel(String level);
+
+    void info(String string);
+
+    void error(String message);
+
+    void error(String message, Throwable throwable);
+
+    OutputStream getStderrOutputStream();
+
+    OutputStream getStdoutOutputStream();
+}

content-config/src/main/java/org/xbib/content/config/ExceptionFormatter.java

@@ -0,0 +1,56 @@
+package org.xbib.content.config;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+/**
+ * Format java exception messages and stack traces.
+ */
+public final class ExceptionFormatter {
+
+    private ExceptionFormatter() {
+    }
+
+    /**
+     * Format exception with stack trace.
+     *
+     * @param t the thrown object
+     * @return the formatted exception
+     */
+    public static String format(Throwable t) {
+        StringBuilder sb = new StringBuilder();
+        append(sb, t, 0, true);
+        return sb.toString();
+    }
+
+    /**
+     * Append Exception to string builder.
+     */
+    private static void append(StringBuilder sb, Throwable t, int level, boolean details) {
+        if (((t != null) && (t.getMessage() != null)) && (!t.getMessage().isEmpty())) {
+            if (details && (level > 0)) {
+                sb.append("\n\nCaused by\n");
+            }
+            sb.append(t.getMessage());
+        }
+        if (details) {
+            if (t != null) {
+                if ((t.getMessage() != null) && (t.getMessage().isEmpty())) {
+                    sb.append("\n\nCaused by ");
+                } else {
+                    sb.append("\n\n");
+                }
+            }
+            StringWriter sw = new StringWriter();
+            if (t != null) {
+                t.printStackTrace(new PrintWriter(sw));
+            }
+            sb.append(sw.toString());
+        }
+        if (t != null) {
+            if (t.getCause() != null) {
+                append(sb, t.getCause(), level + 1, details);
+            }
+        }
+    }
+}

content-config/src/main/java/org/xbib/content/config/SystemConfigLogger.java

@@ -0,0 +1,37 @@
+package org.xbib.content.config;
+
+import java.io.OutputStream;
+
+public class SystemConfigLogger implements ConfigLogger {
+
+    @Override
+    public void setLevel(String level) {
+        // d nothing
+    }
+
+    @Override
+    public void info(String string) {
+        System.out.println(string);
+    }
+
+    @Override
+    public void error(String message) {
+        System.err.println(message);
+    }
+
+    @Override
+    public void error(String message, Throwable throwable) {
+        System.err.println(message);
+        System.err.println(ExceptionFormatter.format(throwable));
+    }
+
+    @Override
+    public OutputStream getStderrOutputStream() {
+        return System.err;
+    }
+
+    @Override
+    public OutputStream getStdoutOutputStream() {
+        return System.out;
+    }
+}

content-core/src/main/java/org/xbib/content/json/JsonSettingsLoader.java

@@ -2,9 +2,6 @@ package org.xbib.content.json;
 
 import org.xbib.content.XContent;
 import org.xbib.content.settings.AbstractSettingsLoader;
-
-import java.util.Collections;
-import java.util.HashSet;
 import java.util.Set;
 
 /**
@@ -13,7 +10,7 @@ import java.util.Set;
  */
 public class JsonSettingsLoader extends AbstractSettingsLoader {
 
-    private static final Set<String> JSON_SUFFIXES = new HashSet<>(Collections.singletonList("json"));
+    private static final Set<String> JSON_SUFFIXES = Set.of("json");
 
     @Override
     public XContent content() {

content-yaml/src/main/java/org/xbib/content/yaml/YamlSettingsLoader.java

@@ -3,8 +3,6 @@ package org.xbib.content.yaml;
 import org.xbib.content.XContent;
 import org.xbib.content.settings.AbstractSettingsLoader;
 import java.io.IOException;
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
@@ -14,7 +12,7 @@ import java.util.Set;
  */
 public class YamlSettingsLoader extends AbstractSettingsLoader {
 
-    private static final Set<String> YAML_SUFFIXES = new HashSet<>(Arrays.asList("yml", "yaml"));
+    private static final Set<String> YAML_SUFFIXES = Set.of("yml", "yaml");
 
     @Override
     public XContent content() {

gradle.properties

@@ -1,6 +1,6 @@
 group = org.xbib
 name = content
-version = 2.3.2
+version = 2.4.0
 
 gradle.wrapper.version = 6.4.1
 xbib.net.version = 2.1.0

settings.gradle

@@ -1,3 +1,4 @@
+include 'content-config'
 include 'content-core'
 include 'content-resource'
 include 'content-language'