cern.gp.beans

Class BeanUtils

java.lang.Object

cern.gp.beans.BeanUtils

public class BeanUtils
extends java.lang.Object

A few utility methods for Beans.

Author:

Lionel Mestre

Method Summary

Modifier and Type	Method and Description
static void	addWeakListenerByReflection(java.beans.PropertyChangeListener listener, java.lang.Object source) Add a weak PropertyChangeListener to an object, using reflection to look up the addPropertyChangeListener method
static java.lang.Class	findTargetClass(java.lang.Object bean) Finds the first public superclass of the given bean.
static java.lang.String	generateUniqueBeanName(java.lang.Object bean) Generates a unique name for the bean using the same convention as the implementation of toString() in Object, which is : "bean class name"+@+"hash code of the bean in hexadecimal"
static boolean	hasExplicitBeanInfo(java.lang.Class clazz) Checks whether there is an explicit bean info for given class.
static java.awt.Image	loadImage(java.lang.String imagePathname, java.lang.Class relatedClass) This is a utility method to help in loading icon images.
static void	registerBeanInfoSearchPaths(java.lang.String[] pathsToRegister) Registers a set of paths in the BeanInfo search path of the java.beans.Introspector.
static void	registerEditorSearchPaths(java.lang.String[] pathsToRegister) Registers a set of paths in the PropertyEditor search path of the java.beans.PropertyEditorManager.

Methods inherited from class java.lang.Object

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

Method Detail

generateUniqueBeanName

public static final java.lang.String generateUniqueBeanName(java.lang.Object bean)

Generates a unique name for the bean using the same convention as the implementation of toString() in Object, which is : "bean class name"+@+"hash code of the bean in hexadecimal"

Parameters:

bean - the bean the name has to be generated from

Returns:

a unique name for the bean

registerEditorSearchPaths

public static final void registerEditorSearchPaths(java.lang.String[] pathsToRegister)

Registers a set of paths in the PropertyEditor search path of the java.beans.PropertyEditorManager.

Use this method when you have PropertyEditor named following the convention TypenameEditor that are not located in the same package as Typename. For a given java type a.b.X, the java.beans.PropertyEditorManager will first check if there is an editor registered for the type, if not it will look for the editor a.b.XEditor and if not found it will look in the search path for the class XEditor. You can use this method to register the path where XEditor is. For instance, if the editor is located in a.c.d.XEditor you would pass in parameter to this method new String[] {"a.c.d"}.

Note that paths are not added if they are already present.

Parameters:

pathsToRegister - the array of paths to register in the search path of the PropertyEditorManager.

registerBeanInfoSearchPaths

public static final void registerBeanInfoSearchPaths(java.lang.String[] pathsToRegister)

Registers a set of paths in the BeanInfo search path of the java.beans.Introspector.

Use this method when you have BeanInfo named following the convention BeanNameBeanInfo that are not located in the same package as BeanName. For a given java bean a.b.X, the java.beans. Introspector will first check if there is a BeanInfo a.b.XBeanInfo and if not found it will look in the search path for the class XBeanInfo. You can use this method to register the path where XBeanInfo is. For instance, if the BeanInfo is located in a.c.d.XBeanInfo you would pass in parameter to this method new String [] {"a.c.d"}.

Note that paths are not added if they are already present.

Parameters:

pathsToRegister - the array of paths to register in the search path of the Introspector.

loadImage

public static final java.awt.Image loadImage(java.lang.String imagePathname,
                                             java.lang.Class relatedClass)

This is a utility method to help in loading icon images. It takes the pathname of a resource file associated with the a given class and loads an image object from that file. Typically images will be GIFs.

The pathname should be relative to the given class and be contained in the classpath. For instance if the related class is in cern.gp.beans and the icon is stored in cern/gp/beans/images/MyIcon.gif the pathname to give would be images/MyIcon.gif.

Parameters:

imagePathname - A pathname relative to the directory holding the class file of the given relatedClass. For example, images/MyIcon.gif.

relatedClass - the class the image is related with.

Returns:

an image object. May be null if the load failed.

findTargetClass

public static final java.lang.Class findTargetClass(java.lang.Object bean)

Finds the first public superclass of the given bean. Should not introspect on a private class, because then the method objects used for the property descriptors will not be callable without an IllegalAccessException, even if overriding a public method from a public superclass.

Parameters:

bean - the bean to find the public class from

Returns:

the first public superclass, possibly the class of the given bean

hasExplicitBeanInfo

public static final boolean hasExplicitBeanInfo(java.lang.Class clazz)

Checks whether there is an explicit bean info for given class.

Parameters:

clazz - the class to test

Returns:

true if explicit bean info exists

addWeakListenerByReflection

public static void addWeakListenerByReflection(java.beans.PropertyChangeListener listener,
                                               java.lang.Object source)

Add a weak PropertyChangeListener to an object, using reflection to look up the addPropertyChangeListener method

Parameters:

listener - the listener to add

source - the object to which a PCL shall be added