org.jfree.util
Class ObjectUtilities

java.lang.Object
  org.jfree.util.ObjectUtilities

public final class ObjectUtilities
extends Object

A collection of useful static utility methods for handling classes and object instantiation.

Author:

Thomas Morgner

Field Summary

static String	CLASS_CONTEXT A constant for using the ClassContext as source for the classloader.
static String	THREAD_CONTEXT A constant for using the TheadContext as source for the classloader.

Method Summary

static Object	clone(Object object) Returns a clone of the specified object, if it can be cloned, otherwise throws a CloneNotSupportedException.
static Collection	deepClone(Collection collection) Returns a new collection containing clones of all the items in the specified collection.
static boolean	equal(Object o1, Object o2) Returns true if the two objects are equal OR both null.
static ClassLoader	getClassLoader() Returns the custom classloader or null, if no custom classloader is defined.
static ClassLoader	getClassLoader(Class c) Returns the classloader, which was responsible for loading the given class.
static String	getClassLoaderSource() Returns the internal configuration entry, whether the classloader of the thread context or the context classloader should be used.
static URL	getResource(String name, Class c) Returns the resource specified by the absolute name.
static InputStream	getResourceAsStream(String name, Class context) Returns the inputstream for the resource specified by the absolute name.
static URL	getResourceRelative(String name, Class c) Returns the resource specified by the relative name.
static InputStream	getResourceRelativeAsStream(String name, Class context) Returns the inputstream for the resource specified by the relative name.
static int	hashCode(Object object) Returns a hash code for an object, or zero if the object is null.
static boolean	isJDK14() Returns true if this is version 1.4 or later of the Java runtime.
static Object	loadAndInstantiate(String className, Class source) Tries to create a new instance of the given class.
static Object	loadAndInstantiate(String className, Class source, Class type) Tries to create a new instance of the given class.
static void	setClassLoader(ClassLoader classLoader) Redefines the custom classloader.
static void	setClassLoaderSource(String classLoaderSource) Defines the internal configuration entry, whether the classloader of the thread context or the context classloader should be used.

Methods inherited from class java.lang.Object

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

Field Detail

THREAD_CONTEXT

public static final String THREAD_CONTEXT

A constant for using the TheadContext as source for the classloader.

See Also:

Constant Field Values

CLASS_CONTEXT

public static final String CLASS_CONTEXT

A constant for using the ClassContext as source for the classloader.

See Also:

Constant Field Values

Method Detail

getClassLoaderSource

public static String getClassLoaderSource()

Returns the internal configuration entry, whether the classloader of the thread context or the context classloader should be used.

Returns:

the classloader source, either THREAD_CONTEXT or CLASS_CONTEXT.

setClassLoaderSource

public static void setClassLoaderSource(String classLoaderSource)

Defines the internal configuration entry, whether the classloader of the thread context or the context classloader should be used.

This setting can only be defined using the API, there is no safe way to put this into an external configuration file.

Parameters:

classLoaderSource - the classloader source, either THREAD_CONTEXT or CLASS_CONTEXT.

equal

public static boolean equal(Object o1,
                            Object o2)

Returns true if the two objects are equal OR both null.

Parameters:

o1 - object 1 (null permitted).

o2 - object 2 (null permitted).

Returns:

true or false.

hashCode

public static int hashCode(Object object)

Returns a hash code for an object, or zero if the object is null.

Parameters:

object - the object (null permitted).

Returns:

The object's hash code (or zero if the object is null).

clone

public static Object clone(Object object)
                    throws CloneNotSupportedException

Returns a clone of the specified object, if it can be cloned, otherwise throws a CloneNotSupportedException.

Parameters:

object - the object to clone (null not permitted).

Returns:

A clone of the specified object.

Throws:

CloneNotSupportedException - if the object cannot be cloned.

deepClone

public static Collection deepClone(Collection collection)
                            throws CloneNotSupportedException

Returns a new collection containing clones of all the items in the specified collection.

Parameters:

collection - the collection (null not permitted).

Returns:

A new collection containing clones of all the items in the specified collection.

Throws:

CloneNotSupportedException - if any of the items in the collection cannot be cloned.

setClassLoader

public static void setClassLoader(ClassLoader classLoader)

Redefines the custom classloader.

Parameters:

classLoader - the new classloader or null to use the default.

getClassLoader

public static ClassLoader getClassLoader()

Returns the custom classloader or null, if no custom classloader is defined.

Returns:

the custom classloader or null to use the default.

getClassLoader

public static ClassLoader getClassLoader(Class c)

Returns the classloader, which was responsible for loading the given class.

Parameters:

c - the classloader, either an application class loader or the boot loader.

Returns:

the classloader, never null.

Throws:

SecurityException - if the SecurityManager does not allow to grab the context classloader.

getResource

public static URL getResource(String name,
                              Class c)

Returns the resource specified by the absolute name.

Parameters:

name - the name of the resource

c - the source class

Returns:

the url of the resource or null, if not found.

getResourceRelative

public static URL getResourceRelative(String name,
                                      Class c)

Returns the resource specified by the relative name.

Parameters:

name - the name of the resource relative to the given class

c - the source class

Returns:

the url of the resource or null, if not found.

getResourceAsStream

public static InputStream getResourceAsStream(String name,
                                              Class context)

Returns the inputstream for the resource specified by the absolute name.

Parameters:

name - the name of the resource

context - the source class

Returns:

the url of the resource or null, if not found.

getResourceRelativeAsStream

public static InputStream getResourceRelativeAsStream(String name,
                                                      Class context)

Returns the inputstream for the resource specified by the relative name.

Parameters:

name - the name of the resource relative to the given class

context - the source class

Returns:

the url of the resource or null, if not found.

loadAndInstantiate

public static Object loadAndInstantiate(String className,
                                        Class source)

Tries to create a new instance of the given class. This is a short cut for the common bean instantiation code.

Parameters:

className - the class name as String, never null.

source - the source class, from where to get the classloader.

Returns:

the instantiated object or null, if an error occured.

loadAndInstantiate

public static Object loadAndInstantiate(String className,
                                        Class source,
                                        Class type)

Tries to create a new instance of the given class. This is a short cut for the common bean instantiation code. This method is a type-safe method and will not instantiate the class unless it is an instance of the given type.

Parameters:

className - the class name as String, never null.

source - the source class, from where to get the classloader.

type - the type.

Returns:

the instantiated object or null, if an error occurred.

isJDK14

public static boolean isJDK14()

Returns true if this is version 1.4 or later of the Java runtime.

Returns:

A boolean.