Add support for multi-release jars (#2442)

Author: felixbarny

apm-agent/pom.xml

@@ -417,13 +417,6 @@
                                         <exclude>**/*</exclude>
                                     </excludes>
                                 </filter>
-                                <filter>
-                                    <artifact>*:*</artifact>
-                                    <excludes>
-                                        <exclude>**/module-info.class</exclude>
-                                        <exclude>META-INF/versions/**</exclude>
-                                    </excludes>
-                                </filter>
                                 <filter>
                                     <artifact>org.apache.logging.log4j:log4j-core</artifact>
                                     <!--Keep in sync with apm-agent-attach-cli/pom.xml-->

elastic-apm-agent/pom.xml

@@ -134,6 +134,10 @@
                                     <fileset dir="${project.basedir}/target/classes/agent" includes="**/*.class" />
                                     <mapper type="regexp" from="^(.*)\.class$$" to="\1\.esclazz" />
                                 </move>
+                                <move todir="${project.basedir}/target/classes/META-INF/versions" overwrite="true">
+                                    <fileset dir="${project.basedir}/target/classes/agent/META-INF/versions" includes="**" />
+                                    <mapper type="regexp" from="^(\d+)/(.*)$$" to="\1/agent/\2" />
+                                </move>
                             </target>
 
                         </configuration>
@@ -208,6 +212,7 @@
                                         <Can-Redefine-Classes>true</Can-Redefine-Classes>
                                         <Can-Retransform-Classes>true</Can-Retransform-Classes>
                                         <Can-Set-Native-Method-Prefix>true</Can-Set-Native-Method-Prefix>
+                                        <Multi-Release>true</Multi-Release>
                                     </manifestEntries>
                                 </transformer>
                             </transformers>

elastic-apm-agent/src/test/java/co/elastic/apm/agent/premain/AgentPackagingIT.java

@@ -39,6 +39,7 @@
 import java.util.jar.Manifest;
 import java.util.stream.Collectors;
 import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -160,4 +161,11 @@ public String value() {
                 })
                 .isTrue());
     }
+
+    @Test
+    void testMultiReleaseJar() throws Exception {
+        JarFile jarFile = new JarFile(agentJar.toFile(), false, ZipFile.OPEN_READ, Runtime.Version.parse("9"));
+        assertThat(jarFile.isMultiRelease()).isTrue();
+        assertThat(jarFile.getJarEntry("agent/org/apache/logging/log4j/util/StackLocator.esclazz").getRealName()).startsWith("META-INF/versions/9");
+    }
 }

pom.xml

@@ -398,7 +398,10 @@
                 <groupId>org.jacoco</groupId>
                 <artifactId>jacoco-maven-plugin</artifactId>
                 <configuration>
-                    <excludes>**/*.esclazz</excludes>
+                    <excludes>
+                        <exclude>**/*.esclazz</exclude>
+                        <exclude>**/*.jar</exclude>
+                    </excludes>
                 </configuration>
                 <executions>
                     <execution>