com.valhalla.pluginmanager
Class PluginLoader

java.lang.Object
  java.lang.ClassLoader
      com.valhalla.pluginmanager.PluginLoader

public class PluginLoader
extends java.lang.ClassLoader

This class supports the loading of custom plugins from jar files. The main class in the Jar should be named after the jar filename and should be in the "package" String passed to the PluginLoader package. For example, the plugin LookAndFeel would be in a jar file called LookAndFeel.jar, and if the package parameter was com.valhalla.jbother.plugins there would need to be a class called com.valhalla.jbother.plugins.LookAndFeel in the jar file

Version:

1.0

Author:

Adam Olsen

Method Summary

java.lang.String	findLibrary(java.lang.String lib) Finds which plugin contains the specified native library, extracts it to a temporary location, and returns the path to that location or null if the native library could not be found.
void	findPlugins(java.lang.String d) Reads in all the available plugins and the information about them
static int	getAPIVersion() Gets the current plugin API version
java.util.ArrayList	getAvailablePlugins()
java.util.ArrayList	getIncompatiblePlugins()
java.util.ArrayList	getInstalledPlugins()
static PluginLoader	getInstance() Gets the singleton of this class
java.util.ArrayList	getInvalidPlugins()
protected java.util.Hashtable	getLoadedClasses()
java.util.Hashtable	getLoadedPlugins()
static PluginLoader	getNewInstance()
PluginJAR	getPlugin(java.lang.String name) Returns the jar file for the specified plugin name
java.io.InputStream	getResourceAsStream(java.lang.String resource) Gets a resource as a stream
java.lang.Class	loadClass(java.lang.String className, boolean resolveIt) Loads the Class out of the plugin file
void	loadPlugins() Attempts to load the available plugins

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLoadedClass, findResource, findResources, findSystemClass, getPackage, getPackages, getParent, getResource, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static PluginLoader getInstance()

Gets the singleton of this class

Returns:

the PluginLoader singleton

getNewInstance

public static PluginLoader getNewInstance()

findLibrary

public java.lang.String findLibrary(java.lang.String lib)

Finds which plugin contains the specified native library, extracts it to a temporary location, and returns the path to that location or null if the native library could not be found.

Overrides:

findLibrary in class java.lang.ClassLoader

Parameters:

the - name of the library

Returns:

the location of the newly created temporary file

getLoadedPlugins

public java.util.Hashtable getLoadedPlugins()

Returns:

a list of currently loaded plugins

getAvailablePlugins

public java.util.ArrayList getAvailablePlugins()

Returns:

a list of available plugins

getInstalledPlugins

public java.util.ArrayList getInstalledPlugins()

Returns:

a list of installed plugins

getInvalidPlugins

public java.util.ArrayList getInvalidPlugins()

Returns:

a list of invalid plugins

getIncompatiblePlugins

public java.util.ArrayList getIncompatiblePlugins()

Returns:

a list of incompatible plugins

getPlugin

public PluginJAR getPlugin(java.lang.String name)

Returns the jar file for the specified plugin name

Parameters:

name - the plugin name

Returns:

the jar file corresponding to the name

getAPIVersion

public static int getAPIVersion()

Gets the current plugin API version

Returns:

the current plugin API version

loadPlugins

public void loadPlugins()

Attempts to load the available plugins

findPlugins

public void findPlugins(java.lang.String d)

Reads in all the available plugins and the information about them

getResourceAsStream

public java.io.InputStream getResourceAsStream(java.lang.String resource)

Gets a resource as a stream

Overrides:

getResourceAsStream in class java.lang.ClassLoader

Parameters:

resource - the resource to get

Returns:

the stream

getLoadedClasses

protected java.util.Hashtable getLoadedClasses()

loadClass

public java.lang.Class loadClass(java.lang.String className,
                                 boolean resolveIt)
                          throws java.lang.ClassNotFoundException

Loads the Class out of the plugin file

Overrides:

loadClass in class java.lang.ClassLoader

Parameters:

className - the class name to load

resolveIt - true to resolve the class (load dependancies)

Returns:

the Class if it was found

Throws:

ClassNotFoundException - if the class could not be found in the system or any of the plugin files

java.lang.ClassNotFoundException