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.ProtectionDomainFactoryoptionalProtectionDomainFactory| Constructor and Description |
|---|
CachingJavaSourceClassLoader(java.lang.ClassLoader parentClassLoader,
java.io.File[] optionalSourcePath,
java.lang.String optionalCharacterEncoding,
java.io.File cacheDirectory)
|
CachingJavaSourceClassLoader(java.lang.ClassLoader parentClassLoader,
ResourceFinder sourceFinder,
java.lang.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 java.util.Map |
generateBytecodes(java.lang.String className)
Override
JavaSourceClassLoader.generateBytecodes(String) to implement class file caching. |
findClass, setCompileErrorHandler, setDebuggingInfo, setSourceFileCharacterEncoding, setSourcePath, setWarningHandlermain, setProtectionDomainFactoryclearAssertionStatus, 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, setSignerspublic CachingJavaSourceClassLoader(java.lang.ClassLoader parentClassLoader,
java.io.File[] optionalSourcePath,
java.lang.String optionalCharacterEncoding,
java.io.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(java.lang.ClassLoader parentClassLoader,
ResourceFinder sourceFinder,
java.lang.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.javaoptionalCharacterEncoding - 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 java.util.Map generateBytecodes(java.lang.String className)
throws java.lang.ClassNotFoundException
JavaSourceClassLoader.generateBytecodes(String) to implement class file caching.generateBytecodes in class JavaSourceClassLoadernull if no source code could be foundjava.lang.ClassNotFoundException - Compilation problems or class file cache I/O problems