Class PluginClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.pf4j.PluginClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class PluginClassLoader
extends URLClassLoader

One instance of this class should be created by plugin manager for every available plug-in. By default, this class loader is a Parent Last ClassLoader - it loads the classes from the plugin's jars before delegating to the parent class loader. Use parentFirst to change the loading strategy.

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	JAVA_PACKAGE_PREFIX
private static final org.slf4j.Logger	log
private boolean	parentFirst
private static final String	PLUGIN_PACKAGE_PREFIX
private PluginDescriptor	pluginDescriptor
private PluginManager	pluginManager

Constructor Summary

Constructors

Constructor	Description
PluginClassLoader(PluginManager pluginManager, PluginDescriptor pluginDescriptor, ClassLoader parent)
PluginClassLoader(PluginManager pluginManager, PluginDescriptor pluginDescriptor, ClassLoader parent, boolean parentFirst)	If parentFirst is true, indicates that the parent ClassLoader should be consulted before trying to load the a class through this loader.

Method Summary

Modifier and Type	Method	Description
void	addFile(File file)
void	addURL(URL url)
URL	getResource(String name)	Load the named resource from this plugin.
Enumeration<URL>	getResources(String name)
Class<?>	loadClass(String className)	By default, it uses a child first delegation model rather than the standard parent first.
private Class<?>	loadClassFromDependencies(String className)

Methods inherited from class URLClassLoader

close, definePackage, findClass, findResource, findResources, getPermissions, getResourceAsStream, getURLs, newInstance, newInstance

Methods inherited from class SecureClassLoader

defineClass, defineClass

Methods inherited from class ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class Object

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

Field Details

log

private static final org.slf4j.Logger log

JAVA_PACKAGE_PREFIX

private static final String JAVA_PACKAGE_PREFIX

See Also:

• Constant Field Values

PLUGIN_PACKAGE_PREFIX

private static final String PLUGIN_PACKAGE_PREFIX

See Also:

• Constant Field Values

pluginManager

private PluginManager pluginManager

pluginDescriptor

private PluginDescriptor pluginDescriptor

parentFirst

private boolean parentFirst

Constructor Details

PluginClassLoader

public PluginClassLoader(PluginManager pluginManager,
 PluginDescriptor pluginDescriptor,
 ClassLoader parent)

PluginClassLoader

public PluginClassLoader(PluginManager pluginManager,
 PluginDescriptor pluginDescriptor,
 ClassLoader parent,
 boolean parentFirst)

If parentFirst is true, indicates that the parent ClassLoader should be consulted before trying to load the a class through this loader.

Method Details

addURL

public void addURL(URL url)

Overrides:

addURL in class URLClassLoader

addFile

public void addFile(File file)

loadClass

public Class<?> loadClass(String className)
                   throws ClassNotFoundException

By default, it uses a child first delegation model rather than the standard parent first. If the requested class cannot be found in this class loader, the parent class loader will be consulted via the standard ClassLoader.loadClass(String) mechanism. Use parentFirst to change the loading strategy.

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

getResource

public URL getResource(String name)

Load the named resource from this plugin. By default, this implementation checks the plugin's classpath first then delegates to the parent. Use parentFirst to change the loading strategy.

Overrides:

getResource in class ClassLoader

Parameters:

name - the name of the resource.

Returns:

the URL to the resource, null if the resource was not found.

getResources

public Enumeration<URL> getResources(String name)
                              throws IOException

Overrides:

getResources in class ClassLoader

Throws:

IOException

loadClassFromDependencies

private Class<?> loadClassFromDependencies(String className)