com.jivesoftware.util
Class ClassUtils

java.lang.Object
  com.jivesoftware.util.ClassUtils

public class ClassUtils
extends java.lang.Object

A utility class to assist with loading classes or resources by name. Many application servers use custom classloaders, which will break uses of:

    Class.forName(className);
 

This utility attempts to load the class or resource using a number of different mechanisms to work around this problem.

Method Summary

static java.lang.Class	forName(java.lang.String className) Loads the class with the specified name.
static java.net.URL	getResource(java.lang.String resourceName, java.lang.Class callingClass) Load a given resource.
static java.io.InputStream	getResourceAsStream(java.lang.String name) Loads the given resource as a stream.
static java.io.InputStream	getResourceAsStream(java.lang.String resourceName, java.lang.Class callingClass) This is a convenience method to load a resource as a stream.
static java.lang.Class	loadClass(java.lang.String className, java.lang.Class callingClass) Load a class with a given name.
static java.lang.Object	newInstance(java.lang.String className) Creates a new instance of the class with the specified name.
static void	propertiesLoaded()
static byte[]	readStream(java.io.InputStream in, int size)

Methods inherited from class java.lang.Object

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

Method Detail

forName

public static java.lang.Class forName(java.lang.String className)
                               throws java.lang.ClassNotFoundException

Loads the class with the specified name.

Parameters:

className - the name of the class

Returns:

the resulting Class object

Throws:

java.lang.ClassNotFoundException - if the class was not found

newInstance

public static java.lang.Object newInstance(java.lang.String className)
                                    throws java.lang.ClassNotFoundException,
                                           java.lang.IllegalAccessException,
                                           java.lang.InstantiationException

Creates a new instance of the class with the specified name.

Parameters:

className - The name of the class

Returns:

A new instance of the class with the specified name.

Throws:

java.lang.ClassNotFoundException - If class cannot be found.

java.lang.IllegalAccessException - If caller cannot access the class.

java.lang.InstantiationException - If class instantiation fails.

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String name)

Loads the given resource as a stream.

Parameters:

name - the name of the resource that exists in the classpath.

Returns:

the resource as an input stream or null if the resource was not found.

propertiesLoaded

public static void propertiesLoaded()

loadClass

public static java.lang.Class loadClass(java.lang.String className,
                                        java.lang.Class callingClass)
                                 throws java.lang.ClassNotFoundException

Load a class with a given name.

It will try to load the class in the following order:

• From Thread.currentThread().getContextClassLoader()
• Using the basic Class.forName(String)
• From ClassLoaderUtil.class.getClassLoader()
• From the callingClass.getClassLoader()

Parameters:

className - The name of the class to load

callingClass - The Class object of the calling object

Throws:

java.lang.ClassNotFoundException - If the class cannot be found anywhere.

getResource

public static java.net.URL getResource(java.lang.String resourceName,
                                       java.lang.Class callingClass)

Load a given resource.

This method will try to load the resource using the following methods (in order):

• From Thread.currentThread().getContextClassLoader()
• From ClassLoaderUtil.class.getClassLoader()
• From the callingClass.getClassLoader()

Parameters:

resourceName - The name of the resource to load

callingClass - The Class object of the calling object

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String resourceName,
                                                      java.lang.Class callingClass)

This is a convenience method to load a resource as a stream.

The algorithm used to find the resource is given in getResource()

Parameters:

resourceName - The name of the resource to load

callingClass - The Class object of the calling object

readStream

public static byte[] readStream(java.io.InputStream in,
                                int size)
                         throws java.io.IOException

Throws:

java.io.IOException