jodd.util

Class ClassLoaderUtil

java.lang.Object

jodd.util.ClassLoaderUtil

public class ClassLoaderUtil
extends java.lang.Object

Utilities to manipulate class path, define and find classes etc.

Constructor Summary

Constructors

Constructor and Description
ClassLoaderUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static void	addFileToClassPath(java.io.File path, java.lang.ClassLoader classLoader) Adds additional file or path to classpath during runtime.
static void	addUrlToClassPath(java.net.URL url, java.lang.ClassLoader classLoader) Adds the content pointed by the URL to the classpath during runtime.
static java.lang.Class	defineClass(java.lang.String className, byte[] classData) Defines a class from byte array into the system class loader.
static java.lang.Class	defineClass(java.lang.String className, byte[] classData, java.lang.ClassLoader classLoader) Defines a class from byte array into the specified class loader.
static java.lang.Class	findClass(java.lang.String className, java.io.File[] classPath, java.lang.ClassLoader parent)
static java.lang.Class	findClass(java.lang.String className, java.net.URL[] classPath, java.lang.ClassLoader parent) Finds and loads class on classpath even if it was already loaded.
static java.io.File	findToolsJar() Finds tools.jar.
static java.io.InputStream	getClassAsStream(java.lang.Class clazz) Opens a class of the specified name for reading using class classloader.
static java.io.InputStream	getClassAsStream(java.lang.String className) Opens a class of the specified name for reading.
static java.io.InputStream	getClassAsStream(java.lang.String className, java.lang.ClassLoader classLoader) Opens a class of the specified name for reading using provided class loader.
static java.lang.String	getClassFileName(java.lang.Class clazz) Resolves class file name from class name by replacing dot's with '/' separator and adding class extension at the end.
static java.lang.String	getClassFileName(java.lang.String className) Resolves class file name from class name by replacing dot's with '/' separator.
static java.lang.ClassLoader	getClassLoader(java.lang.Class<?> clazz) Returns class loader of a class, considering the security manager.
static java.lang.String	getClasspathItemBaseDir(java.io.File classpathItem) Returns base folder for classpath item.
static java.util.jar.Manifest	getClasspathItemManifest(java.io.File classpathItem) Returns classpath item manifest or null if not found.
static java.lang.ClassLoader	getContextClassLoader() Returns thread context class loader.
static java.lang.ClassLoader	getDefaultClassLoader() Returns default class loader.
static java.io.File[]	getDefaultClasspath() Returns default classpath using default classloader.
static java.io.File[]	getDefaultClasspath(java.lang.ClassLoader classLoader) Returns default class path from all available URLClassLoader in classloader hierarchy.
static java.io.InputStream	getResourceAsStream(java.lang.String resourceName) Opens a resource of the specified name for reading.
static java.io.InputStream	getResourceAsStream(java.lang.String resourceName, boolean useCache) Opens a resource of the specified name for reading.
static java.io.InputStream	getResourceAsStream(java.lang.String resourceName, java.lang.ClassLoader callingClass) Opens a resource of the specified name for reading.
static java.io.InputStream	getResourceAsStream(java.lang.String resourceName, java.lang.ClassLoader callingClass, boolean useCache) Opens a resource of the specified name for reading.
static java.io.File	getResourceFile(java.lang.String resourceName) Retrieves resource as file.
static java.io.File	getResourceFile(java.lang.String resourceName, java.lang.ClassLoader classLoader) Retrieves resource as file.
static java.net.URL	getResourceUrl(java.lang.String resourceName) Retrieves given resource as URL.
static java.net.URL	getResourceUrl(java.lang.String resourceName, java.lang.ClassLoader classLoader) Retrieves given resource as URL.
static java.lang.ClassLoader	getSystemClassLoader() Returns system class loader.
static java.lang.Class	loadClass(java.lang.String className) Loads a class using default class loader strategy.
static java.lang.Class	loadClass(java.lang.String className, java.lang.ClassLoader classLoader) Loads a class using default class loader strategy.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassLoaderUtil

public ClassLoaderUtil()

Method Detail

getClassLoader

public static java.lang.ClassLoader getClassLoader(java.lang.Class<?> clazz)

Returns class loader of a class, considering the security manager.

getDefaultClassLoader

public static java.lang.ClassLoader getDefaultClassLoader()

Returns default class loader. By default, it is threads context class loader. If this one is null, then class loader of the caller class is returned.

getContextClassLoader

public static java.lang.ClassLoader getContextClassLoader()

Returns thread context class loader.

getSystemClassLoader

public static java.lang.ClassLoader getSystemClassLoader()

Returns system class loader.

addFileToClassPath

public static void addFileToClassPath(java.io.File path,
                      java.lang.ClassLoader classLoader)

Adds additional file or path to classpath during runtime.

See Also:

addUrlToClassPath(java.net.URL, ClassLoader)

addUrlToClassPath

public static void addUrlToClassPath(java.net.URL url,
                     java.lang.ClassLoader classLoader)

Adds the content pointed by the URL to the classpath during runtime. Uses reflection since addURL method of URLClassLoader is protected.

defineClass

public static java.lang.Class defineClass(java.lang.String className,
                          byte[] classData)

Defines a class from byte array into the system class loader.

See Also:

defineClass(String, byte[], ClassLoader)

defineClass

public static java.lang.Class defineClass(java.lang.String className,
                          byte[] classData,
                          java.lang.ClassLoader classLoader)

Defines a class from byte array into the specified class loader. Warning: this is a hack!

Parameters:

className - optional class name, may be null

classData - bytecode data

classLoader - classloader that will load class

findClass

public static java.lang.Class findClass(java.lang.String className,
                        java.io.File[] classPath,
                        java.lang.ClassLoader parent)

See Also:

findClass(String, java.net.URL[], ClassLoader)

findClass

public static java.lang.Class findClass(java.lang.String className,
                        java.net.URL[] classPath,
                        java.lang.ClassLoader parent)

Finds and loads class on classpath even if it was already loaded.

Parameters:

className - class name to find

classPath - classpath

parent - optional parent class loader, may be null

findToolsJar

public static java.io.File findToolsJar()

Finds tools.jar. Returns null if does not exist.

getClasspathItemManifest

public static java.util.jar.Manifest getClasspathItemManifest(java.io.File classpathItem)

Returns classpath item manifest or null if not found.

getClasspathItemBaseDir

public static java.lang.String getClasspathItemBaseDir(java.io.File classpathItem)

Returns base folder for classpath item. If item is a (jar) file, its parent is returned. If item is a directory, its name is returned.

getDefaultClasspath

public static java.io.File[] getDefaultClasspath()

Returns default classpath using default classloader.

getDefaultClasspath

public static java.io.File[] getDefaultClasspath(java.lang.ClassLoader classLoader)

Returns default class path from all available URLClassLoader in classloader hierarchy. The following is added to the classpath list:

• file URLs from URLClassLoader (other URL protocols are ignored)
• inner entries from containing manifest files (if exist)
• bootstrap classpath

getResourceUrl

public static java.net.URL getResourceUrl(java.lang.String resourceName)

Retrieves given resource as URL.

See Also:

getResourceUrl(String, ClassLoader)

getResourceUrl

public static java.net.URL getResourceUrl(java.lang.String resourceName,
                          java.lang.ClassLoader classLoader)

Retrieves given resource as URL. Resource is always absolute and may starts with a slash character.

Resource will be loaded using class loaders in the following order:

• Thread.currentThread().getContextClassLoader()
• ClassLoaderUtil.class.getClassLoader()
• if callingClass is provided: callingClass.getClassLoader()

getResourceFile

public static java.io.File getResourceFile(java.lang.String resourceName)

Retrieves resource as file.

See Also:

getResourceFile(String)

getResourceFile

public static java.io.File getResourceFile(java.lang.String resourceName,
                           java.lang.ClassLoader classLoader)

Retrieves resource as file. Resource is retrieved as URL, than it is converted to URI so it can be used by File constructor.

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String resourceName)
                                               throws java.io.IOException

Opens a resource of the specified name for reading.

Throws:

java.io.IOException

See Also:

getResourceAsStream(String, ClassLoader)

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String resourceName,
                                      boolean useCache)
                                               throws java.io.IOException

Opens a resource of the specified name for reading.

Throws:

java.io.IOException

See Also:

getResourceAsStream(String, ClassLoader, boolean)

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String resourceName,
                                      java.lang.ClassLoader callingClass)
                                               throws java.io.IOException

Opens a resource of the specified name for reading.

Throws:

java.io.IOException

See Also:

getResourceUrl(String, ClassLoader)

getResourceAsStream

public static java.io.InputStream getResourceAsStream(java.lang.String resourceName,
                                      java.lang.ClassLoader callingClass,
                                      boolean useCache)
                                               throws java.io.IOException

Opens a resource of the specified name for reading. Controls caching, that is important when the same jar is reloaded using custom classloader.

Throws:

java.io.IOException

getClassAsStream

public static java.io.InputStream getClassAsStream(java.lang.Class clazz)
                                            throws java.io.IOException

Opens a class of the specified name for reading using class classloader.

Throws:

java.io.IOException

See Also:

getResourceAsStream(String, ClassLoader)

getClassAsStream

public static java.io.InputStream getClassAsStream(java.lang.String className)
                                            throws java.io.IOException

Opens a class of the specified name for reading. No specific classloader is used for loading class.

Throws:

java.io.IOException

See Also:

getResourceAsStream(String, ClassLoader)

getClassAsStream

public static java.io.InputStream getClassAsStream(java.lang.String className,
                                   java.lang.ClassLoader classLoader)
                                            throws java.io.IOException

Opens a class of the specified name for reading using provided class loader.

Throws:

java.io.IOException

loadClass

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

Loads a class using default class loader strategy.

Throws:

java.lang.ClassNotFoundException

See Also:

DefaultClassLoaderStrategy

loadClass

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

Loads a class using default class loader strategy.

Throws:

java.lang.ClassNotFoundException

See Also:

DefaultClassLoaderStrategy

getClassFileName

public static java.lang.String getClassFileName(java.lang.Class clazz)

Resolves class file name from class name by replacing dot's with '/' separator and adding class extension at the end. If array, component type is returned.

getClassFileName

public static java.lang.String getClassFileName(java.lang.String className)

Resolves class file name from class name by replacing dot's with '/' separator.