Provides interfaces for tools which can be invoked from a program, for example, compilers.

These interfaces and classes are required as part of the Java Platform, Standard Edition (Java SE), but there is no requirement to provide any tools implementing them.

Unless explicitly allowed, all methods in this package might throw a NullPointerException if given a null argument or if given a list or collection containing null elements. Similarly, no method may return null unless explicitly allowed.

This package is the home of the Java programming language compiler framework. This framework allows clients of the framework to locate and run compilers from programs. The framework also provides Service Provider Interfaces (SPI) for structured access to diagnostics (DiagnosticListener) as well as a file abstraction for overriding file access (JavaFileManager and JavaFileObject). See JavaCompiler for more details on using the SPI.

There is no requirement for a compiler at runtime. However, if a default compiler is provided, it can be located using the ToolProvider, for example:

JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

It is possible to provide alternative compilers or tools through the service provider mechanism.

For example, if com.vendor.VendorJavaCompiler is a provider of the JavaCompiler tool then its jar file would contain the file META-INF/services/ This file would contain the single line:


If the jar file is on the class path, VendorJavaCompiler can be located using code like this:

JavaCompiler compiler = ServiceLoader.load(JavaCompiler.class).iterator().next();