com.sun.jini.start

Class ClassLoaderUtil

java.lang.Object

com.sun.jini.start.ClassLoaderUtil

public class ClassLoaderUtil
extends Object

This class provides useful utilities for creating and manipulating class loaders.

Author:

Sun Microsystems, Inc.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static Logger	logger Configure logger

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ClassLoaderUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static void	displayClassLoaderTree(ClassLoader classloader) Utility method that displays the class loader delegation tree for the given class loader.
static void	displayContextClassLoaderTree() Utility method that displays the class loader delegation tree for the current context class loader.
private static ArrayList	getClassLoaderTree(ClassLoader classloader) Utility method that retrieves the components making up the class loader delegation tree for the given classloader parameter and returns them via an ArrayList.
static URL[]	getClasspathURLs(String classpath) Utility method that converts the components of a String representing a classpath into file URL(s).
static URL[]	getCodebaseURLs(String codebase) Utility method that converts the components of a String representing a codebase into standard URL(s).
private static ArrayList	getContextClassLoaderTree() Utility method that retrieves the components making up the class loader delegation tree for the current context class loader and returns each in an ArrayList.
static URL[]	getImportCodebaseURLs(String importCodebase) Utility method that converts the components of a String representing a codebase or classpath into URL(s).

Methods inherited from class java.lang.Object

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

Field Detail

logger

static final Logger logger

Configure logger

Constructor Detail

ClassLoaderUtil

private ClassLoaderUtil()

Method Detail

getClasspathURLs

public static URL[] getClasspathURLs(String classpath)
                              throws IOException,
                                     MalformedURLException

Utility method that converts the components of a String representing a classpath into file URL(s).

Parameters:

classpath - String containing components separated by path separators that represent the components making up a classpath

Returns:

a URL[] where each element of the array corresponds to one of the components in the classpath parameter. The path components are (potentially) expanded via File.getCanonicalFile() before converting to a URL format.

Throws:

MalformedURLException - If the path cannot be parsed as a URL

java.net.IOException - If an I/O error occurs, which is possible because the construction of the canonical pathname may require filesystem queries

IOException

getCodebaseURLs

public static URL[] getCodebaseURLs(String codebase)
                             throws MalformedURLException

Utility method that converts the components of a String representing a codebase into standard URL(s).

Parameters:

codebase - String containing components separated by spaces in which each component is in URL format.

Returns:

a URL[] where each element of the array corresponds to one of the components in the codebase parameter

Throws:

MalformedURLException

getImportCodebaseURLs

public static URL[] getImportCodebaseURLs(String importCodebase)
                                   throws IOException,
                                          MalformedURLException

Utility method that converts the components of a String representing a codebase or classpath into URL(s).

Parameters:

importCodebase - String assumed (in order) to be either 1) a space delimited set of URL(s) representing a codebase or 2) a File.pathSeparator delimited set of class paths.

Returns:

a URL[] where each element of the array corresponds to one of the components in the importCodebase parameter

Throws:

MalformedURLException - If the path cannot be parsed as a URL

java.net.IOException - If an I/O error occurs, which is possible because the construction of the canonical pathname may require filesystem queries

IOException

getContextClassLoaderTree

private static ArrayList getContextClassLoaderTree()

Utility method that retrieves the components making up the class loader delegation tree for the current context class loader and returns each in an ArrayList.

Returns:

an ArrayList instance in which each element of the list is one of the components making up the current delegation tree.

getClassLoaderTree

private static ArrayList getClassLoaderTree(ClassLoader classloader)

Utility method that retrieves the components making up the class loader delegation tree for the given classloader parameter and returns them via an ArrayList.

Parameters:

classloader - ClassLoader instance whose delegation tree is to be retrieved and returned

Returns:

an ArrayList instance in which each element of the list is one of the components making up the delegation tree of the given class loader.

displayContextClassLoaderTree

public static void displayContextClassLoaderTree()

Utility method that displays the class loader delegation tree for the current context class loader. For each class loader in the tree, this method displays the locations from which that class loader will retrieve and load requested classes.

This method can be useful when debugging problems related to the receipt of exceptions such as ClassNotFoundException.

displayClassLoaderTree

public static void displayClassLoaderTree(ClassLoader classloader)

Utility method that displays the class loader delegation tree for the given class loader. For each class loader in the tree, this method displays the locations from which that class loader will retrieve and load requested classes.

This method can be useful when debugging problems related to the receipt of exceptions such as ClassNotFoundException.

Parameters:

classloader - ClassLoader instance whose delegation tree is to be displayed