Use muti-release jar to fallback mvnd-client to original maven

client/pom.xml

@@ -31,8 +31,7 @@
   <name>Maven Daemon - Client</name>
 
   <properties>
-    <maven.compiler.target>11</maven.compiler.target>
-    <maven.compiler.source>11</maven.compiler.source>
+    <maven.compiler.release>11</maven.compiler.release>
     <graalvm-native-static-opt/>
     <graalvm-native-glibc-opt/>
   </properties>
@@ -88,6 +87,7 @@
             <configuration>
               <rules>
                 <enforceBytecodeVersion>
+                  <maxJdkVersion>${maven.compiler.release}</maxJdkVersion>
                   <excludes>
                     <exclude>org.graalvm.nativeimage:svm</exclude>
                   </excludes>
@@ -115,11 +115,48 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>default-compile</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>fallback-main</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <release>${maven-dist.required.jdk}</release>
+              <compileSourceRoots>
+                <root>${project.basedir}/src/main/java-fallback</root>
+              </compileSourceRoots>
+            </configuration>
+          </execution>
+          <execution>
+            <id>mvnd-main</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <multiReleaseOutput>true</multiReleaseOutput>
+              <compileSourceRoots>
+                <root>${project.basedir}/src/main/java-mvnd</root>
+              </compileSourceRoots>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-jar-plugin</artifactId>
         <configuration>
-          <compilerArgs>
-            <arg>--add-exports=java.base/sun.nio.ch=ALL-UNNAMED</arg>
-            <arg>--add-exports=java.base/jdk.internal.module=ALL-UNNAMED</arg>
-          </compilerArgs>
+          <archive>
+            <manifestEntries>
+              <Multi-Release>true</Multi-Release>
+            </manifestEntries>
+          </archive>
         </configuration>
       </plugin>
       <plugin>

client/src/main/java-fallback/org/mvndaemon/mvnd/client/DefaultClient.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019 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.
+ */
+package org.mvndaemon.mvnd.client;
+
+import org.apache.maven.cli.MavenCli;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+public class DefaultClient {
+    public static void main(String[] argv) throws Exception {
+        final String logbackConfFallback = System.getProperty("logback.configurationFile.fallback");
+        if (null != logbackConfFallback && !"".equals(logbackConfFallback)) {
+            System.setProperty("logback.configurationFile", logbackConfFallback);
+            System.clearProperty("logback.configurationFile.fallback");
+        }
+
+        final Logger LOGGER = LoggerFactory.getLogger(DefaultClient.class);
+	LOGGER.warn("Found old JDK, fallback to the embedded maven!");
+	LOGGER.warn("Use JDK 11+ to run maven-mvnd client!");
+
+        MavenCli.main(argv);
+    }
+}

client/src/main/java/org/mvndaemon/mvnd/client/DefaultClient.java → client/src/main/java-mvnd/org/mvndaemon/mvnd/client/DefaultClient.java

@@ -68,6 +68,8 @@ public class DefaultClient implements Client {
     private final DaemonParameters parameters;
 
     public static void main(String[] argv) throws Exception {
+        System.clearProperty("logback.configurationFile.fallback");
+
         final List<String> args = new ArrayList<>(Arrays.asList(argv));
 
         // Log file

common/pom.xml

@@ -88,7 +88,7 @@
             <artifactId>maven-compiler-plugin</artifactId>
             <executions>
               <execution>
-                <id>default</id>
+                <id>default-compile</id>
                 <goals>
                   <goal>compile</goal>
                 </goals>
@@ -143,7 +143,7 @@
             <artifactId>maven-compiler-plugin</artifactId>
             <executions>
               <execution>
-                <id>default</id>
+                <id>default-compile</id>
                 <goals>
                   <goal>compile</goal>
                 </goals>

daemon/pom.xml

@@ -99,6 +99,29 @@
       </resource>
     </resources>
     <plugins>
+      <plugin>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>default-compile</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>fallback</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <release>${maven-dist.required.jdk}</release>
+              <compileSourceRoots>
+                <root>${project.basedir}/src/main/java-fallback</root>
+              </compileSourceRoots>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-surefire-plugin</artifactId>

dist/src/main/distro/bin/m2.conf

@@ -0,0 +1,27 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+main is org.mvndaemon.mvnd.client.DefaultClient from plexus.core
+
+set maven.home default ${mvnd.home}/mvn
+set maven.conf default ${maven.home}/conf
+set logback.configurationFile default ${mvnd.home}/conf/logback-client.xml
+set logback.configurationFile.fallback default ${maven.conf}/logging/logback.xml
+
+[plexus.core]
+load ${maven.conf}/logging
+load ${maven.home}/lib/ext/*.jar
+load ${maven.home}/lib/*.jar

dist/src/main/distro/bin/mvnd.cmd

@@ -73,22 +73,106 @@ goto error
 
 set MAVEN_CMD_LINE_ARGS=%*
 
+@REM Find the project basedir, i.e., the directory that contains the directory ".mvn".
+@REM Fallback to current working directory if not found.
+
+set "EXEC_DIR=%CD%"
+set "WDIR=%EXEC_DIR%"
+
+@REM Look for the --file switch and start the search for the .mvn directory from the specified
+@REM POM location, if supplied.
+
+set FILE_ARG=
+:arg_loop
+if "%~1" == "-f" (
+  set "FILE_ARG=%~2"
+  shift
+  goto process_file_arg
+)
+if "%~1" == "--file" (
+  set "FILE_ARG=%~2"
+  shift
+  goto process_file_arg
+)
+@REM If none of the above, skip the argument
+shift
+if not "%~1" == "" (
+  goto arg_loop
+) else (
+  goto findBaseDir
+)
+
+:process_file_arg
+if "%FILE_ARG%" == "" (
+  goto findBaseDir
+)
+if not exist "%FILE_ARG%" (
+  echo POM file "%FILE_ARG%" specified the -f/--file command-line argument does not exist >&2
+  goto error
+)
+if exist "%FILE_ARG%\*" (
+  set "POM_DIR=%FILE_ARG%"
+) else (
+  call :get_directory_from_file "%FILE_ARG%"
+)
+if not exist "%POM_DIR%" (
+  echo Directory "%POM_DIR%" extracted from the -f/--file command-line argument "%FILE_ARG%" does not exist >&2
+  goto error
+)
+set "WDIR=%POM_DIR%"
+goto findBaseDir
+
+:get_directory_from_file
+set "POM_DIR=%~dp1"
+:stripPomDir
+if not "_%POM_DIR:~-1%"=="_\" goto pomDirStripped
+set "POM_DIR=%POM_DIR:~0,-1%"
+goto stripPomDir
+:pomDirStripped
+exit /b
+
+:findBaseDir
+cd /d "%WDIR%"
+:findBaseDirLoop
+if exist "%WDIR%\.mvn" goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set "WDIR=%CD%"
+goto findBaseDirLoop
+
+:baseDirFound
+set "MAVEN_PROJECTBASEDIR=%WDIR%"
+cd /d "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+if "_%EXEC_DIR:~-1%"=="_\" set "EXEC_DIR=%EXEC_DIR:~0,-1%"
+set "MAVEN_PROJECTBASEDIR=%EXEC_DIR%"
+cd /d "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+set "jvmConfig=\.mvn\jvm.config"
+if not exist "%MAVEN_PROJECTBASEDIR%%jvmConfig%" goto endReadAdditionalConfig
+
 @setlocal EnableExtensions EnableDelayedExpansion
-for %%i in ("%MVND_HOME%"\mvn\boot\*.jar "%MVND_HOME%"\mvn\lib\ext\*.jar "%MVND_HOME%"\mvn\lib\*.jar) do set DAEMON_JAR=!DAEMON_JAR!;%%i
-@endlocal & set DAEMON_JAR="%DAEMON_JAR%"
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
 
-set DAEMON_LAUNCHER=org.mvndaemon.mvnd.client.DefaultClient
+for %%i in ("%MVND_HOME%"\mvn\boot\plexus-classworlds-*) do set CLASSWORLDS_JAR="%%i"
+set CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
 
 "%JAVACMD%" ^
   %JVM_CONFIG_MAVEN_PROPS% ^
   %MAVEN_OPTS% ^
   %MAVEN_DEBUG_OPTS% ^
-  -classpath %DAEMON_JAR% ^
-  "-Dlogback.configurationFile=%MVND_HOME%\conf\logback-client.xml" ^
+  -classpath %CLASSWORLDS_JAR% ^
+  "-Dclassworlds.conf=%MVND_HOME%\bin\m2.conf"
   "-Dmvnd.home=%MVND_HOME%" ^
-  "-Dmaven.home=%MVND_HOME%\mvn" ^
-  "-Dlibrary.jansi.path=%MVND_HOME%\mvn\lib\jansi-native" ^
-  %DAEMON_LAUNCHER% %MAVEN_CMD_LINE_ARGS%
+  "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" ^
+  %CLASSWORLDS_LAUNCHER% %MAVEN_CMD_LINE_ARGS%
 if ERRORLEVEL 1 goto error
 goto end