org.apache.bcel.util
Class ClassLoader
java.lang.ClassLoader
org.apache.bcel.util.ClassLoader
public class ClassLoader
extends java.lang.ClassLoader
Drop in replacement for the standard class loader of the JVM. You can use it
in conjunction with the JavaWrapper to dynamically modify/create classes
as they're requested.
This class loader recognizes special requests in a distinct
format, i.e., when the name of the requested class contains with
"$$BCEL$$" it calls the createClass() method with that name
(everything bevor the $$BCEL$$ is considered to be the package
name. You can subclass the class loader and override that
method. "Normal" classes class can be modified by overriding the
modifyClass() method which is called just before defineClass().
There may be a number of packages where you have to use the
default class loader (which may also be faster). You can define the
set of packages where to use the system class loader in the
constructor. The default value contains "java.", "sun.",
"javax."
$Id: ClassLoader.java 386056 2006-03-15 11:31:56Z tcurdt $
ClassLoader() - Ignored packages are by default ( "java.", "sun.",
"javax."), i.e.
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ClassLoader(String[] ignored_packages)
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ClassLoader(java.lang.ClassLoader deferTo)
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ClassLoader(java.lang.ClassLoader deferTo, String[] ignored_packages)
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protected JavaClass | createClass(String class_name) - Override this method to create you own classes on the fly.
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protected Class | loadClass(String class_name, boolean resolve)
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protected JavaClass | modifyClass(JavaClass clazz) - Override this method if you want to alter a class before it gets actually
loaded.
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DEFAULT_IGNORED_PACKAGES
public static final String[] DEFAULT_IGNORED_PACKAGES
classes
private Hashtable classes
ignored_packages
private String[] ignored_packages
ClassLoader
public ClassLoader()
Ignored packages are by default ( "java.", "sun.",
"javax."), i.e. loaded by system class loader
ClassLoader
public ClassLoader(String[] ignored_packages)
ignored_packages
- classes contained in these packages will be loaded
with the system class loader
ClassLoader
public ClassLoader(java.lang.ClassLoader deferTo)
deferTo
- delegate class loader to use for ignored packages
ClassLoader
public ClassLoader(java.lang.ClassLoader deferTo,
String[] ignored_packages)
deferTo
- delegate class loader to use for ignored packagesignored_packages
- classes contained in these packages will be loaded
with the system class loader
createClass
protected JavaClass createClass(String class_name)
Override this method to create you own classes on the fly. The
name contains the special token $$BCEL$$. Everything before that
token is consddered to be a package name. You can encode you own
arguments into the subsequent string. You must regard however not
to use any "illegal" characters, i.e., characters that may not
appear in a Java class name too
The default implementation interprets the string as a encoded compressed
Java class, unpacks and decodes it with the Utility.decode() method, and
parses the resulting byte array and returns the resulting JavaClass object.
class_name
- compressed byte code with "$$BCEL$$" in it
loadClass
protected Class loadClass(String class_name,
boolean resolve)
throws ClassNotFoundException
modifyClass
protected JavaClass modifyClass(JavaClass clazz)
Override this method if you want to alter a class before it gets actually
loaded. Does nothing by default.