public class CachingJavaSourceClassLoader extends JavaSourceClassLoader
JavaSourceClassLoader
that uses a resource storage provided by the application to cache
compiled classes and thus saving unnecessary recompilations.
The application provides access to the resource storeage through a pair of a ResourceFinder
and a ResourceCreator
(see CachingJavaSourceClassLoader(ClassLoader, ResourceFinder, String, ResourceFinder, ResourceCreator)
.
See AbstractJavaSourceClassLoader.main(String[])
for an example how to use this class.
Notice: You must NOT rely on that this class stores some particular data in some particular resources through
the given classFileCacheResourceFinder/Creator
! These serve only as a means for the CachingJavaSourceClassLoader
to persistently cache some data between invocations. In other words: If you want to
compile .java
files into .class
files, then don't use this class but Compiler
instead!
AbstractJavaSourceClassLoader.ProtectionDomainFactory
optionalProtectionDomainFactory
Constructor and Description |
---|
CachingJavaSourceClassLoader(ClassLoader parentClassLoader,
File[] optionalSourcePath,
String optionalCharacterEncoding,
File cacheDirectory)
|
CachingJavaSourceClassLoader(ClassLoader parentClassLoader,
ResourceFinder sourceFinder,
String optionalCharacterEncoding,
ResourceFinder classFileCacheResourceFinder,
ResourceCreator classFileCacheResourceCreator)
Notice that this class is thread-safe if and only if the
classFileCacheResourceCreator stores its data
atomically, i.e. |
Modifier and Type | Method and Description |
---|---|
protected Map<String,byte[]> |
generateBytecodes(String className)
Override
JavaSourceClassLoader.generateBytecodes(String) to implement class file caching. |
findClass, setCompileErrorHandler, setDebuggingInfo, setSourceFileCharacterEncoding, setSourcePath, setWarningHandler
main, setProtectionDomainFactory
clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners
public CachingJavaSourceClassLoader(ClassLoader parentClassLoader, File[] optionalSourcePath, String optionalCharacterEncoding, File cacheDirectory)
CachingJavaSourceClassLoader(ClassLoader, ResourceFinder, String, ResourceFinder, ResourceCreator)
.optionalSourcePath
- Directories to scan for source filescacheDirectory
- Directory to use for caching generated class files (see class description)public CachingJavaSourceClassLoader(ClassLoader parentClassLoader, ResourceFinder sourceFinder, String optionalCharacterEncoding, ResourceFinder classFileCacheResourceFinder, ResourceCreator classFileCacheResourceCreator)
classFileCacheResourceCreator
stores its data
atomically, i.e. the classFileCacheResourceFinder
sees the resource written by the classFileCacheResourceCreator
only after the OutputStream
is closed.
In order to make the caching scheme work, both the classFileCacheResourceFinder
and the sourceFinder
must support the Resource.lastModified()
method, so that
the modification time of the source and the class files can be compared.
parentClassLoader
- Attempt to load classes through this one before looking for source filessourceFinder
- Finds Java™ source for class pkg.Cls
in resource pkg/Cls.java
optionalCharacterEncoding
- Encoding of Java™ source or null
for platform default
encodingclassFileCacheResourceFinder
- Finds precompiled class pkg.Cls
in resource pkg/Cls.class
(see class description)classFileCacheResourceCreator
- Stores compiled class pkg.Cls
in resource pkg/Cls.class
(see
class description)protected Map<String,byte[]> generateBytecodes(String className) throws ClassNotFoundException
JavaSourceClassLoader.generateBytecodes(String)
to implement class file caching.generateBytecodes
in class JavaSourceClassLoader
null
if no source code could be foundClassNotFoundException
- Compilation problems or class file cache I/O problemsCopyright © 2001–2016. All rights reserved.