anon.util

Class ClassUtil

java.lang.Object

anon.util.ClassUtil

public final class ClassUtil
extends java.lang.Object

This class performs some basic operations related to Class objects.

Author:

Rolf Wendolsky

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ClassUtil.Package Represents a package name.

Method Summary

Modifier and Type	Method and Description
static void	addFileToClasspath(java.io.File a_file)
static void	addFileToClasspath(java.lang.String a_file)
static void	addURLToClasspath(java.net.URL a_url)
static void	enableFindSubclasses(boolean a_benable)
static java.util.Vector	findSubclasses(java.lang.Class a_class) Gets all classes that extend the given class or implement the given interface, including the class itself.
static java.lang.Class	getCallingClassStatic() Returns the class that called the current method.
static java.io.File	getClassDirectory(java.lang.Class a_class) Returns the class directory of the specified class.
static java.io.File	getClassDirectory(java.lang.String a_className)
static java.lang.String	getClassNameStatic() Returns the name, including the package, of the calling method's class.
static java.lang.String	getClassPath() Returns the current java class path.
static java.lang.Class	getClassStatic() Returns the current class from a static context.
static java.io.File	getFile()
static java.lang.Class	getFirstClassFound(java.io.File a_file) Traverse a file, directory or zip/jar file recursive until a class file is found and instantiated or all files are traversed.
static java.util.zip.ZipFile	getJarFile() returns a Java Object of the JAP.jar or null if JAP is not started as jar-file
static java.util.zip.ZipFile	getJarFile(java.lang.Class a_class)
static java.io.File	getResourceDirectory(java.lang.String a_classOrResourceName, java.lang.Class a_class) Returns the class/resource directory of the specified class/resource.
static java.lang.String	getShortClassName(java.lang.Class a_class) Gets the name of a class without package (everything before the last "." is removed).
static java.lang.String	getUserDir() Returns the content of the system property user.dir
static boolean	isFindSubclassesEnabled()
static java.util.Enumeration	loadClasses() Loads all classes into cache that are in the same file structure as this class and as the calling class.
static java.util.Enumeration	loadClasses(java.lang.Class a_rootClass)
static java.util.Enumeration	loadClasses(java.io.File a_classDirectory)
static java.lang.String	toRelativeResourcePath(java.lang.Class a_class) Generates a relative resource path to the given class.

Methods inherited from class java.lang.Object

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

Method Detail

addFileToClasspath

public static void addFileToClasspath(java.lang.String a_file)
                               throws java.io.IOException,
                                      java.lang.IllegalAccessException

Throws:

java.io.IOException

java.lang.IllegalAccessException

addFileToClasspath

public static void addFileToClasspath(java.io.File a_file)
                               throws java.lang.IllegalAccessException

Throws:

java.lang.IllegalAccessException

addURLToClasspath

public static void addURLToClasspath(java.net.URL a_url)
                              throws java.lang.IllegalAccessException

Throws:

java.lang.IllegalAccessException

getShortClassName

public static java.lang.String getShortClassName(java.lang.Class a_class)

Gets the name of a class without package (everything before the last "." is removed).

Parameters:

a_class - a Class

Returns:

the name of the class without package

getClassStatic

public static java.lang.Class getClassStatic()

Returns the current class from a static context. This method is a replacement to this.getClass() in a static environment, as this is not available there.

Returns:

the current class

getClassNameStatic

public static java.lang.String getClassNameStatic()

Returns the name, including the package, of the calling method's class.

Returns:

the name, including the package, of the calling method's class

getCallingClassStatic

public static java.lang.Class getCallingClassStatic()

Returns the class that called the current method. This method is an alternative to Object.getClass(), as the caller is not needed to be an argument or an Object either.

Returns:

the class that called the current method

getUserDir

public static java.lang.String getUserDir()

Returns the content of the system property user.dir

Returns:

the content of the system property user.dir

getClassPath

public static java.lang.String getClassPath()

Returns the current java class path.

Returns:

the current java class path

enableFindSubclasses

public static void enableFindSubclasses(boolean a_benable)

isFindSubclassesEnabled

public static boolean isFindSubclassesEnabled()

findSubclasses

public static java.util.Vector findSubclasses(java.lang.Class a_class)

Gets all classes that extend the given class or implement the given interface, including the class itself. It is recommended to store this information somewhere and reuse it instead of calling this method again, as all known classes have to be searched at each call. If classes from special packages should be found, it is recommended to load those packages at program start. Otherwise, some classes in those packages, that inherit from classes in this or other packages, can not be found. WARNING: this may be slow at the first call, especially for large packages

Parameters:

a_class - a Class

Returns:

all known subclasses of the given class

loadClasses

public static java.util.Enumeration loadClasses()

Loads all classes into cache that are in the same file structure as this class and as the calling class. Recommended to be called at program start to initially fill the cache. WARNING: this may be slow at the first call, especially for large packages (like the JRE)

Returns:

all loaded classes

loadClasses

public static java.util.Enumeration loadClasses(java.lang.Class a_rootClass)

loadClasses

public static java.util.Enumeration loadClasses(java.io.File a_classDirectory)

getClassDirectory

public static java.io.File getClassDirectory(java.lang.String a_className)

getFile

public static java.io.File getFile()

getJarFile

public static java.util.zip.ZipFile getJarFile()

returns a Java Object of the JAP.jar or null if JAP is not started as jar-file

getJarFile

public static java.util.zip.ZipFile getJarFile(java.lang.Class a_class)

getClassDirectory

public static java.io.File getClassDirectory(java.lang.Class a_class)
                                      throws java.lang.NullPointerException

Returns the class directory of the specified class. The class directory is either the directory in that the highest package in the package structure of the class is contained, or the jar-File in that the class is contained. For extracting the contents of a jar-File, see ZipFile.

Parameters:

a_class - a class

Returns:

the class directory of the specified class, either a real directory or a Jar-file or null if the directory/jar-file does not exist

Throws:

java.lang.NullPointerException

getResourceDirectory

public static java.io.File getResourceDirectory(java.lang.String a_classOrResourceName,
                                                java.lang.Class a_class)
                                         throws java.lang.NullPointerException

Returns the class/resource directory of the specified class/resource. The directory is either the directory in that the highest package in the package structure of the class/resource is contained, or the jar-File in that the class/resource is contained. For extracting the contents of a jar-File, see ZipFile.

Parameters:

a_classOrResourceName - a filename of a class/resource to lock for

a_class - a class of which the classloader is used to lock for the requested class/resource

Returns:

the class directory of the specified class, either a real directory or a Jar-file or null if the directory/jar-file does not exist

Throws:

java.lang.NullPointerException

toRelativeResourcePath

public static java.lang.String toRelativeResourcePath(java.lang.Class a_class)

Generates a relative resource path to the given class.

Parameters:

a_class - Class

Returns:

URL

getFirstClassFound

public static java.lang.Class getFirstClassFound(java.io.File a_file)

Traverse a file, directory or zip/jar file recursive until a class file is found and instantiated or all files are traversed. The instantiated class is returned.

Parameters:

a_file - a file, directory or zip/jar file

Returns:

the first class that was instnatiated or null if no class could be found and instantiated