Put module-info.class in the jar root instead of a multi-release jar

build.gradle

@@ -63,7 +63,7 @@ repositories {
 configurations {
     bootstrap
     genresources
-    java9
+    jpms
 }
 
 ext {
@@ -127,9 +127,6 @@ dependencies {
     implementation "com.github.javaparser:javaparser-core:${javaparserVersion}"
     implementation "com.github.javaparser:javaparser-symbol-solver-core:${javaparserVersion}"
 
-    // only necessary to compile against JDK8 internals - for Java9+ there's a multimodule implementation
-    implementation 'com.sun.org.apache.xml.internal:resolver:20050927'
-
     // NOTE: newer JUnit breaks some tests for some reason
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.10.3'
     testImplementation 'org.junit.jupiter:junit-jupiter-params:5.10.3'
@@ -161,16 +158,17 @@ dependencies {
     genresources "com.github.javaparser:javaparser-core:${javaparserVersion}"
     genresources "com.github.javaparser:javaparser-symbol-solver-core:${javaparserVersion}"
 
-    // need an own configuration for Java9 builds, as the maven plugin module-config is overlapping lot
-    java9 "org.apache.logging.log4j:log4j-api:${log4jVersion}"
-    java9("net.sf.saxon:Saxon-HE:${saxonVersion}") {
+    // module path for compiling module-info.java - kept separate, as the maven plugin dependencies
+    // would otherwise end up on the module path too
+    jpms "org.apache.logging.log4j:log4j-api:${log4jVersion}"
+    jpms("net.sf.saxon:Saxon-HE:${saxonVersion}") {
         exclude group: 'xml-apis', module: 'xml-apis'
         exclude group: 'org.apache.httpcomponents', module: 'httpclient'
         exclude group: 'org.apache.httpcomponents', module: 'httpcore'
     }
-    java9 "org.apache.ant:ant:${antVersion}"
-    java9 "com.github.javaparser:javaparser-core:${javaparserVersion}"
-    java9("com.github.javaparser:javaparser-symbol-solver-core:${javaparserVersion}") {
+    jpms "org.apache.ant:ant:${antVersion}"
+    jpms "com.github.javaparser:javaparser-core:${javaparserVersion}"
+    jpms("com.github.javaparser:javaparser-symbol-solver-core:${javaparserVersion}") {
         exclude group: 'com.google.guava', module: 'failureaccess'
         exclude group: 'com.google.guava', module: 'listenablefuture'
         exclude group: 'com.google.code.findbugs', module: 'jsr305'
@@ -286,21 +284,20 @@ compileTestJava {
     dependsOn testSchemas.collect {"${it.name}_SchemaGen" }
 }
 
-task compileJava9(type: JavaCompile) {
+// Compiles module-info.java on its own: the already compiled classes are patched into the module
+// and its dependencies are taken from the module path. The module-info.class ends up in the jar root.
+tasks.register('compileModuleInfo', JavaCompile) {
     dependsOn 'compileJava'
-
-    javaCompiler = javaToolchains.compilerFor {
-        languageVersion = JavaLanguageVersion.of(jdkVersion)
-    }
-    sourceCompatibility = 17
-    targetCompatibility = 17
-    destinationDirectory = file('build/classes/java9/main/META-INF/versions/9')
-    source = file('src/main/java9')
+    options.release = 17
+    destinationDirectory = layout.buildDirectory.dir('classes/jpms/main')
+    source = file('src/main/jpms')
     classpath = files()
-    options.compilerArgs = [
-        '--patch-module', "org.apache.xmlbeans=${sourceSets.main.output.asPath}",
-        '--module-path',  files(sourceSets.main.output.files + configurations.java9.asFileTree.files).asPath
-    ]
+    doFirst {
+        options.compilerArgs = [
+            '--patch-module', "org.apache.xmlbeans=${sourceSets.main.output.asPath}",
+            '--module-path', files(sourceSets.main.output.files + configurations.jpms.files).asPath
+        ]
+    }
 }
 
 processTestResources {
@@ -310,7 +307,7 @@ processTestResources {
 task export4anttest(type: Copy) {
     dependsOn 'jar'
     into "build/libs"
-    from configurations.java9
+    from configurations.jpms
 }
 
 test {
@@ -330,7 +327,6 @@ idea {
 }
 
 jar {
-    dependsOn compileJava9
     archiveBaseName = "xmlbeans-${XMLBeansVersion}"
 
     from(project.rootDir) {
@@ -339,7 +335,7 @@ jar {
         into 'META-INF'
     }
 
-    from('build/classes/java9/main')
+    from(tasks.named('compileModuleInfo'))
 
     from('src/main/maven') {
         exclude '**/*.java'
@@ -350,7 +346,6 @@ jar {
     duplicatesStrategy = DuplicatesStrategy.INCLUDE
 
     manifest {
-        attributes('Multi-Release':'true')
         attributes([
                 'Comment': "Apache XmlBeans version ${XMLBeansVersion}",
                 'Specification-Title': 'Apache XmlBeans',
@@ -375,6 +370,7 @@ javadocJar {
 
 sourcesJar {
     archiveBaseName = "xmlbeans-${XMLBeansVersion}"
+    from('src/main/jpms')
     metaInf {
         from("$projectDir/LICENSE.txt")
         from("$projectDir/NOTICE.txt")
@@ -824,6 +820,8 @@ animalsniffer {
     //sourceSets = [sourceSets.main]
     ignore 'javax.xml.stream.*'
     ignore 'javax.xml.namespace.*'
+    // only used by the maven plugin, which never runs on Android
+    ignore 'javax.xml.catalog.*'
 }
 
 // The Android API signature only makes sense for code we ship. ParseUrlRedirectTest

build.xml

@@ -152,15 +152,12 @@
     <dependency prefix="maven-model" artifact="org.apache.maven:maven-model:3.9.16" usage="maven-plugin"/>
     <dependency prefix="maven-plugin-api" artifact="org.apache.maven:maven-plugin-api:3.9.16" usage="maven-plugin"/>
     <dependency prefix="maven-plugin-annotations" artifact="org.apache.maven.plugin-tools:maven-plugin-annotations:3.15.2" usage="maven-plugin"/>
-    <!-- only necessary to compile against JDK8 internals - for Java9+ there's a mulitmodule implementation -->
-    <dependency prefix="xml-resolver" artifact="com.sun.org.apache.xml.internal:resolver:20050927" usage="maven-plugin"/>
 
     <path id="maven-plugin">
         <pathelement location="${maven-core.jar}"/>
         <pathelement location="${maven-model.jar}"/>
         <pathelement location="${maven-plugin-api.jar}"/>
         <pathelement location="${maven-plugin-annotations.jar}"/>
-        <pathelement location="${xml-resolver.jar}"/>
     </path>
 
     <path id="xmlbeans-test">
@@ -206,6 +203,7 @@
             we often had hard-to-find build/CI-problems because of these! -->
         <delete dir="compile-lib"/>
         <delete dir="lib/main" includes="javaparser-core-3.1*.jar,javaparser-core-3.23.0.jar,slf4j*.jar,Saxon-HE-10.2.jar"/>
+        <delete dir="lib/maven-plugin" includes="resolver-20050927.jar"/>
         <delete dir="lib/tests" includes="slf4j*.jar"/>
         <delete dir="lib/util" includes="forbiddenapis-2.6.jar,forbiddenapis-3.4.jar,apache-rat-0.12.jar"/>
         <condition property="jars.present">
@@ -229,7 +227,6 @@
                     <available file="${maven-model.jar}"/>
                     <available file="${maven-plugin-api.jar}"/>
                     <available file="${maven-plugin-annotations.jar}"/>
-                    <available file="${xml-resolver.jar}"/>
                 </and>
                 <isset property="disconnected"/>
             </or>
@@ -267,7 +264,6 @@
         <downloadfile dest="${maven-model.jar}" src="${maven-model.url}"/>
         <downloadfile dest="${maven-plugin-api.jar}" src="${maven-plugin-api.url}"/>
         <downloadfile dest="${maven-plugin-annotations.jar}" src="${maven-plugin-annotations.url}"/>
-        <downloadfile dest="${xml-resolver.jar}" src="${xml-resolver.url}"/>
     </target>
 
     <macrodef name="schemaComp">
@@ -439,14 +435,14 @@
             <classpath refid="maven-plugin"/>
         </javac>
 
+        <mkdir dir="build/classes-jpms"/>
         <javac release="17"
-               srcdir="${basedir}/src/main/multimodule/java9"
-               destdir="${basedir}/src/main/multimodule/java9"
+               srcdir="${basedir}/src/main/jpms"
+               destdir="build/classes-jpms"
                includeantruntime="false"
                debug="${compile.debug}"
                debuglevel="lines,vars,source"
-               fork="true"
-               unless:true="${isJava8}">
+               fork="true">
             <compilerarg line="--patch-module org.apache.xmlbeans=${basedir}/build/classes"/>
             <modulepath>
                 <pathelement path="lib/main"/>
@@ -660,14 +656,13 @@
             <fileset dir="build/classes" excludes="org/apache/xmlbeans/impl/schema/TypeSystemHolder.template"/>
             <fileset dir="." includes="LICENSE.txt,NOTICE.txt"/>
             <fileset dir="build/generated-resources"/>
-            <zipfileset dir="src/main/multimodule/java9" prefix="META-INF/versions/9" excludes="**/*.java"/>
+            <fileset dir="build/classes-jpms"/>
             <zipfileset dir="build/maven" prefix="META-INF/maven"/>
             <mappedresources>
                 <fileset dir="src/main/resources" excludes="maven/**"/>
                 <cutdirsmapper dirs="1"/>
             </mappedresources>
             <manifest>
-                <attribute name="Multi-Release" value="true"/>
                 <section name="org/apache/xmlbeans/">
                     <attribute name="Comment" value="Apache XmlBeans version ${version.base}"/>
                     <attribute name="Implementation-Title" value="org.apache.xmlbeans"/>

src/main/java/org/apache/xmlbeans/impl/tool/MavenPluginResolver.java

@@ -15,22 +15,26 @@
 
 package org.apache.xmlbeans.impl.tool;
 
-import com.sun.org.apache.xml.internal.resolver.CatalogManager;
-import com.sun.org.apache.xml.internal.resolver.tools.CatalogResolver;
-import org.apache.xmlbeans.impl.util.SuppressForbidden;
 import org.xml.sax.EntityResolver;
 
+import javax.xml.catalog.Catalog;
+import javax.xml.catalog.CatalogFeatures;
+import javax.xml.catalog.CatalogManager;
+import java.io.File;
+
 /**
- * Helper class for XML catalogs, which is provided as Java 8 and Java 9+ version (multi release)
+ * Helper class for XML catalogs, based on the JDK {@code javax.xml.catalog} API
  */
-@SuppressForbidden("class is available in Java 8 and multi-release version handles newer official package namespace")
 public class MavenPluginResolver {
     public static EntityResolver getResolver(String catalogLocation) {
         if (catalogLocation == null) {
             return null;
         }
-        CatalogManager catalogManager = CatalogManager.getStaticManager();
-        catalogManager.setCatalogFiles(catalogLocation);
-        return new CatalogResolver(catalogManager);
+
+        CatalogFeatures features = CatalogFeatures.builder()
+            .with(CatalogFeatures.Feature.PREFER, "system")
+            .build();
+        Catalog catalog = CatalogManager.catalog(features, new File(catalogLocation).toURI());
+        return CatalogManager.catalogResolver(catalog);
     }
 }

src/main/maven/org.apache.xmlbeans/xmlbeans/pom.xml

@@ -118,12 +118,6 @@
             <version>3.28.2</version>
             <scope>provided</scope>
         </dependency>
-        <dependency>
-            <groupId>com.sun.org.apache.xml.internal</groupId>
-            <artifactId>resolver</artifactId>
-            <version>20050927</version>
-            <scope>provided</scope>
-        </dependency>
 
         <!-- dependencies for xmlbeans maven plugin -->
         <dependency>