org.jboss.util

Class Classes

java.lang.Object

org.jboss.util.Classes

public final class Classes
extends java.lang.Object

A collection of Class utilities.

Version:

$Revision$

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_PACKAGE_NAME The default package name.
static java.lang.String	PACKAGE_SEPARATOR The string used to separator packages
static char	PACKAGE_SEPARATOR_CHAR The characther used to separator packages
private static java.util.Map	PRIMITIVE_NAME_TYPE_MAP Primitive type name -> class map.
private static java.lang.Class[]	PRIMITIVE_WRAPPER_MAP Map of primitive types to their wrapper classes

Constructor Summary

Constructors

Constructor and Description
Classes()

Method Summary

Modifier and Type	Method and Description
private static java.lang.Class	convertToJavaClass(java.lang.String name, java.lang.ClassLoader cl) Convert a given String into the appropriate Class.
static java.lang.Class<?>[]	convertToJavaClasses(java.util.Iterator<java.lang.String> it, java.lang.ClassLoader cl) Convert a list of Strings from an Interator into an array of Classes (the Strings are taken as classnames).
static void	describe(java.lang.StringBuffer buffer, java.lang.Class clazz) Describe the class
static void	describe(java.lang.StringBuffer buffer, java.lang.Object object) Describe the class of an object
static void	displayClassInfo(java.lang.Class clazz, java.lang.StringBuffer results) Format a string buffer containing the Class, Interfaces, CodeSource, and ClassLoader information for the given object clazz.
static void	forceLoad(java.lang.Class type) Force the given class to be loaded fully.
static void	getAllInterfaces(java.util.List allIfaces, java.lang.Class c) Populates a list with all the interfaces implemented by the argument class c and all its superclasses.
static java.lang.Class[]	getAllUniqueInterfaces(java.lang.Class c) Returns an array containing all the unique interfaces implemented by the argument class c and all its superclasses.
static java.lang.reflect.Method	getAttributeGetter(java.lang.Class cls, java.lang.String attr) Returns attribute's getter method.
static java.lang.reflect.Method	getAttributeSetter(java.lang.Class cls, java.lang.String attr, java.lang.Class type) Returns attribute's setter method.
static java.net.URL[]	getClassLoaderURLs(java.lang.ClassLoader cl) Use reflection to access a URL[] getURLs or URL[] getClasspath method so that non-URLClassLoader class loaders, or class loaders that override getURLs to return null or empty, can provide the true classpath info.
static java.lang.String	getDescription(java.lang.Object object) Describe the class of an object
static java.lang.String	getPackageName(java.lang.Class type) Get the package name of the specified class.
static java.lang.String	getPackageName(java.lang.String classname) Get the package name of the specified class.
static java.lang.Class	getPrimitive(java.lang.Class wrapper)
static java.lang.Class	getPrimitiveTypeForName(java.lang.String name) Get the primitive type for the given primitive name.
static java.lang.Class	getPrimitiveWrapper(java.lang.Class type) Get the wrapper class for the given primitive type.
private static java.lang.String	getProperty(java.lang.String name, java.lang.String defaultValue) Get a system property
static java.lang.Object	instantiate(java.lang.Class expected, java.lang.String property, java.lang.String defaultClassName) Instantiate a java class object
static boolean	isPrimitive(java.lang.Class type) Check if the given class is a primitive class or a primitive wrapper class.
static boolean	isPrimitive(java.lang.String type) Check type against boolean, byte, char, short, int, long, float, double.
static boolean	isPrimitiveWrapper(java.lang.Class type) Check if the given class is a primitive wrapper class.
static java.lang.Class	loadClass(java.lang.String className) This method acts equivalently to invoking Thread.currentThread().getContextClassLoader().loadClass(className); but it also supports primitive types and array classes of object types or primitive types.
static java.lang.Class	loadClass(java.lang.String className, java.lang.ClassLoader classLoader) This method acts equivalently to invoking classLoader.loadClass(className) but it also supports primitive types and array classes of object types or primitive types.
static java.lang.String	stripPackageName(java.lang.Class type) Get the short name of the specified class by striping off the package name.
static java.lang.String	stripPackageName(java.lang.String classname) Get the short name of the specified class by striping off the package name.

Methods inherited from class java.lang.Object

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

Field Detail

PACKAGE_SEPARATOR

public static final java.lang.String PACKAGE_SEPARATOR

The string used to separator packages

See Also:

Constant Field Values

PACKAGE_SEPARATOR_CHAR

public static final char PACKAGE_SEPARATOR_CHAR

The characther used to separator packages

See Also:

Constant Field Values

DEFAULT_PACKAGE_NAME

public static final java.lang.String DEFAULT_PACKAGE_NAME

The default package name.

See Also:

Constant Field Values

PRIMITIVE_NAME_TYPE_MAP

private static final java.util.Map PRIMITIVE_NAME_TYPE_MAP

Primitive type name -> class map.

PRIMITIVE_WRAPPER_MAP

private static final java.lang.Class[] PRIMITIVE_WRAPPER_MAP

Map of primitive types to their wrapper classes

Constructor Detail

Classes

public Classes()

Method Detail

displayClassInfo

public static void displayClassInfo(java.lang.Class clazz,
                                    java.lang.StringBuffer results)

Format a string buffer containing the Class, Interfaces, CodeSource, and ClassLoader information for the given object clazz.

Parameters:

clazz - the Class

results - - the buffer to write the info to

getClassLoaderURLs

public static java.net.URL[] getClassLoaderURLs(java.lang.ClassLoader cl)

Use reflection to access a URL[] getURLs or URL[] getClasspath method so that non-URLClassLoader class loaders, or class loaders that override getURLs to return null or empty, can provide the true classpath info.

Parameters:

cl -

Returns:

the urls

getDescription

public static java.lang.String getDescription(java.lang.Object object)

Describe the class of an object

Parameters:

object - the object

Returns:

the description

describe

public static void describe(java.lang.StringBuffer buffer,
                            java.lang.Object object)

Describe the class of an object

Parameters:

buffer - the string buffer

object - the object

describe

public static void describe(java.lang.StringBuffer buffer,
                            java.lang.Class clazz)

Describe the class

Parameters:

buffer - the string buffer

clazz - the clazz

stripPackageName

public static java.lang.String stripPackageName(java.lang.String classname)

Get the short name of the specified class by striping off the package name.

Parameters:

classname - Class name.

Returns:

Short class name.

stripPackageName

public static java.lang.String stripPackageName(java.lang.Class type)

Get the short name of the specified class by striping off the package name.

Parameters:

type - Class name.

Returns:

Short class name.

getPackageName

public static java.lang.String getPackageName(java.lang.String classname)

Get the package name of the specified class.

Parameters:

classname - Class name.

Returns:

Package name or "" if the classname is in the default package.

Throws:

EmptyStringException - Classname is an empty string.

getPackageName

public static java.lang.String getPackageName(java.lang.Class type)

Get the package name of the specified class.

Parameters:

type - Class.

Returns:

Package name.

forceLoad

public static void forceLoad(java.lang.Class type)

Force the given class to be loaded fully.

This method attempts to locate a static method on the given class the attempts to invoke it with dummy arguments in the hope that the virtual machine will prepare the class for the method call and call all of the static class initializers.

Parameters:

type - Class to force load.

Throws:

NullArgumentException - Type is null.

getPrimitiveTypeForName

public static java.lang.Class getPrimitiveTypeForName(java.lang.String name)

Get the primitive type for the given primitive name.

For example, "boolean" returns Boolean.TYPE and so on...

Parameters:

name - Primitive type name (boolean, int, byte, ...)

Returns:

Primitive type or null.

Throws:

java.lang.IllegalArgumentException - Type is not a primitive class

getPrimitiveWrapper

public static java.lang.Class getPrimitiveWrapper(java.lang.Class type)

Get the wrapper class for the given primitive type.

Parameters:

type - Primitive class.

Returns:

Wrapper class for primitive.

Throws:

java.lang.IllegalArgumentException - Type is not a primitive class

getAllInterfaces

public static void getAllInterfaces(java.util.List allIfaces,
                                    java.lang.Class c)

Populates a list with all the interfaces implemented by the argument class c and all its superclasses.

Parameters:

allIfaces - - the list to populate with the interfaces

c - - the class to start scanning for interfaces

getAllUniqueInterfaces

public static java.lang.Class[] getAllUniqueInterfaces(java.lang.Class c)

Returns an array containing all the unique interfaces implemented by the argument class c and all its superclasses. Interfaces that appear multiple times through inheritence are only accounted for once.

Parameters:

c - - the class to start scanning for interfaces

Returns:

the interfaces

isPrimitiveWrapper

public static boolean isPrimitiveWrapper(java.lang.Class type)

Check if the given class is a primitive wrapper class.

Parameters:

type - Class to check.

Returns:

True if the class is a primitive wrapper.

isPrimitive

public static boolean isPrimitive(java.lang.Class type)

Check if the given class is a primitive class or a primitive wrapper class.

Parameters:

type - Class to check.

Returns:

True if the class is a primitive or primitive wrapper.

isPrimitive

public static boolean isPrimitive(java.lang.String type)

Check type against boolean, byte, char, short, int, long, float, double.

Parameters:

type - The java type name

Returns:

true if this is a primative type name.

getPrimitive

public static java.lang.Class getPrimitive(java.lang.Class wrapper)

Parameters:

wrapper - a primitive wrapper type

Returns:

primitive type the passed in wrapper type corresponds to

instantiate

public static java.lang.Object instantiate(java.lang.Class expected,
                                           java.lang.String property,
                                           java.lang.String defaultClassName)

Instantiate a java class object

Parameters:

expected - the expected class type

property - the system property defining the class

defaultClassName - the default class name

Returns:

the instantiated object

loadClass

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

This method acts equivalently to invoking Thread.currentThread().getContextClassLoader().loadClass(className); but it also supports primitive types and array classes of object types or primitive types.

Parameters:

className - the qualified name of the class or the name of primitive type or array in the same format as returned by the java.lang.Class.getName() method.

Returns:

the Class object for the requested className

Throws:

java.lang.ClassNotFoundException - when the classLoader can not find the requested class

loadClass

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

This method acts equivalently to invoking classLoader.loadClass(className) but it also supports primitive types and array classes of object types or primitive types.

Parameters:

className - the qualified name of the class or the name of primitive type or array in the same format as returned by the java.lang.Class.getName() method.

classLoader - the ClassLoader used to load classes

Returns:

the Class object for the requested className

Throws:

java.lang.ClassNotFoundException - when the classLoader can not find the requested class

convertToJavaClasses

public static final java.lang.Class<?>[] convertToJavaClasses(java.util.Iterator<java.lang.String> it,
                                                              java.lang.ClassLoader cl)
                                                       throws java.lang.ClassNotFoundException

Convert a list of Strings from an Interator into an array of Classes (the Strings are taken as classnames).

Parameters:

it - A java.util.Iterator pointing to a Collection of Strings

cl - The ClassLoader to use

Returns:

Array of Classes

Throws:

java.lang.ClassNotFoundException - When a class could not be loaded from the specified ClassLoader

getAttributeGetter

public static final java.lang.reflect.Method getAttributeGetter(java.lang.Class cls,
                                                                java.lang.String attr)
                                                         throws java.lang.NoSuchMethodException

Returns attribute's getter method. If the method not found then NoSuchMethodException will be thrown.

Parameters:

cls - the class the attribute belongs too

attr - the attribute's name

Returns:

attribute's getter method

Throws:

NoSuchMethodException - if the getter was not found

java.lang.NoSuchMethodException

getAttributeSetter

public static final java.lang.reflect.Method getAttributeSetter(java.lang.Class cls,
                                                                java.lang.String attr,
                                                                java.lang.Class type)
                                                         throws java.lang.NoSuchMethodException

Returns attribute's setter method. If the method not found then NoSuchMethodException will be thrown.

Parameters:

cls - the class the attribute belongs to

attr - the attribute's name

type - the attribute's type

Returns:

attribute's setter method

Throws:

NoSuchMethodException - if the setter was not found

java.lang.NoSuchMethodException

convertToJavaClass

private static final java.lang.Class convertToJavaClass(java.lang.String name,
                                                        java.lang.ClassLoader cl)
                                                 throws java.lang.ClassNotFoundException

Convert a given String into the appropriate Class.

Parameters:

name - Name of class

cl - ClassLoader to use

Returns:

The class for the given name

Throws:

java.lang.ClassNotFoundException - When the class could not be found by the specified ClassLoader

getProperty

private static java.lang.String getProperty(java.lang.String name,
                                            java.lang.String defaultValue)

Get a system property

Parameters:

name - the property name

defaultValue - the default value