com.facebook.buck.jvm.java.runner

Class FileClassPathRunner

java.lang.Object

com.facebook.buck.jvm.java.runner.FileClassPathRunner

public class FileClassPathRunner
extends Object

This class handles extra large classpaths by allowing the client to pass the classpath via file specified by buck.classpath_file. This is to sidestep commandline length limits.

There are 3 modes:

• Java 8 or older launched: We manually add the entries from `buck.classpath_file` to the system classloader.
• Java 9 or newer launched, and Buck is aware of this: We rely on `@argfile` support in newer versions of `java` to pass in our long `-classpath` argument. Here, the JVM adds all the classpath entries itself.
• Java 9 or newer launched, and Buck isn't aware of this: We create a new classloader and add entries from `buck.classpath_file` manually. This approach has problems, e.g. classloading for in-process Java compilation does not work for Buck's own tests, but is provided to support cases where the version of `java` on the path is 9+, but we're targeting 8- for the target under test.

Note: this class only depends on classes present in the JRE, since we don't want to have to push more things on to the classpath when using it.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CLASSPATH_FILE_PROPERTY
static String	TESTRUNNER_CLASSES_PROPERTY

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CLASSPATH_FILE_PROPERTY

public static final String CLASSPATH_FILE_PROPERTY

See Also:

Constant Field Values

TESTRUNNER_CLASSES_PROPERTY

public static final String TESTRUNNER_CLASSES_PROPERTY

See Also:

Constant Field Values

Method Detail

main

public static void main(String[] args)
                 throws IOException,
                        ReflectiveOperationException

Throws:

IOException

ReflectiveOperationException