Apache Maven Compiler Plugin

The Compiler Plugin is used to compile the sources of your project. Since 3.0, the default compiler is javax.tools.JavaCompiler (if you are using java 1.6) and is used to compile Java sources. If you want to force the plugin using javac, you must configure the plugin option forceJavacCompilerUse.

Also note that at present the default source setting is 1.8 and the default target setting is 1.8, independently of the JDK you run Maven with. You are highly encouraged to change these defaults by setting source and target as described in Setting the -source and -target of the Java Compiler.

Other compilers than javac can be used and work has already started on AspectJ, .NET, and C#.

NOTE: To know more about the JDK javac, please see: https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javac.html.

Goals Overview

The Compiler Plugin has two goals. Both are already bound to their proper phases within the Maven Lifecycle and are therefore, automatically executed during their respective phases.

  • compiler:compile is bound to the compile phase and is used to compile the main source files.
  • compiler:testCompile is bound to the test-compile phase and is used to compile the test source files.

Usage

General instructions on how to use the Compiler Plugin can be found on the usage page. Some more specific use cases are described in the examples given below.

In case you still have questions regarding the plugin's usage, please have a look at the FAQ and feel free to contact the user mailing list. The posts to the mailing list are archived and could already contain the answer to your question as part of an older thread. Hence, it is also worth browsing/searching the mail archive.

If you feel like the plugin is missing a feature or has a defect, you can fill a feature request or bug report in our issue tracker. When creating a new issue, please provide a comprehensive description of your concern. Especially for fixing bugs it is crucial that the developers can reproduce your problem. For this reason, entire debug logs, POMs or most preferably little demo projects attached to the issue are very much appreciated. Of course, patches are welcome, too. Contributors can check out the project from our source repository and will find supplementary information in the guide to helping with Maven.

Examples

To provide you with better understanding on some usages of the Compiler Plugin, you can take a look into the following examples: