MNG-5719 reintroduced DefaultJavaToolChain

DefaultJavaToolChain was the only way to access JDK toolchain
javaHome parameter and was used by some clients, notably Tycho.
The class is now marked as deprecated and clients are adviced to
use JavaToolchainImpl instead.

Signed-off-by: Igor Fedorenko <ifedorenko@apache.org>

maven-core/src/main/java/org/apache/maven/toolchain/java/DefaultJavaToolChain.java

@@ -0,0 +1,54 @@
+package org.apache.maven.toolchain.java;
+
+/*
+ * 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.
+ */
+
+import org.apache.maven.toolchain.model.ToolchainModel;
+import org.codehaus.plexus.logging.Logger;
+
+/**
+ * Provides backwards compatibility with Maven 3.2.3 and earlier. Clients that do not require compatibility with Maven
+ * 3.2.3 and earlier are encouraged to use {@link JavaToolchainImpl}.
+ * 
+ * @deprecated clients that do not require compatibility with Maven 3.2.3 and earlier should link to
+ *             {@link JavaToolchainImpl} instead.
+ */
+public class DefaultJavaToolChain
+    extends JavaToolchainImpl
+{
+    public static final String KEY_JAVAHOME = JavaToolchainImpl.KEY_JAVAHOME;
+
+    public DefaultJavaToolChain( ToolchainModel model, Logger logger )
+    {
+        super( model, logger );
+    }
+
+    @Override
+    public String getJavaHome()
+    {
+        return super.getJavaHome();
+    }
+
+    @Override
+    public void setJavaHome( String javaHome )
+    {
+        super.setJavaHome( javaHome );
+    }
+
+}

maven-core/src/main/java/org/apache/maven/toolchain/java/JavaToolchainFactory.java

@@ -59,7 +59,10 @@ public class JavaToolchainFactory
             return null;
         }
 
-        JavaToolchainImpl jtc = new JavaToolchainImpl( model, logger );
+        // use DefaultJavaToolChain for compatibility with maven 3.2.3 and earlier
+
+        @SuppressWarnings( "deprecation" )
+        JavaToolchainImpl jtc = new DefaultJavaToolChain( model, logger );
 
         // populate the provides section
         Properties provides = model.getProvides();