java.beans
Class Introspector

java.lang.Object
  java.beans.Introspector

public class Introspector
extends Object

The Introspector is a utility for developers to figure out which properties, events, and methods a JavaBean supports.

The Introspector class walks over the class/superclass chain of the target bean class. At each level it checks if there is a matching BeanInfo class which provides explicit information about the bean, and if so uses that explicit information. Otherwise it uses the low level reflection APIs to study the target class and uses design patterns to analyze its behaviour and then proceeds to continue the introspection with its baseclass.

To look for the explicit information of a bean:

1. The Introspector appends "BeanInfo" to the qualified name of the bean class, try to use the new class as the "BeanInfo" class. If the "BeanInfo" class exsits and returns non-null value when queried for explicit information, use the explicit information
2. If the first step fails, the Introspector will extract a simple class name of the bean class by removing the package name from the qualified name of the bean class, append "BeanInfo" to it. And look for the simple class name in the packages defined in the "BeanInfo" search path (The default "BeanInfo" search path is sun.beans.infos). If it finds a "BeanInfo" class and the "BeanInfo" class returns non-null value when queried for explicit information, use the explicit information

Field Summary

static int	IGNORE_ALL_BEANINFO Constant values to indicate that the Introspector will ignore all BeanInfo class.
static int	IGNORE_IMMEDIATE_BEANINFO Constant values to indicate that the Introspector will ignore the BeanInfo class of the current bean class.
static int	USE_ALL_BEANINFO Constant values to indicate that the Introspector will use all BeanInfo class which have been found.

Method Summary

static String	decapitalize(String name) Decapitalizes a given string according to the rule: If the first or only character is Upper Case, it is made Lower Case UNLESS the second character is also Upper Case, when the String is returned unchanged
static void	flushCaches() Flushes all BeanInfo caches.
static void	flushFromCaches(Class<?> clazz) Flushes the BeanInfo caches of the specified bean class
static BeanInfo	getBeanInfo(Class<?> beanClass) Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class.
static BeanInfo	getBeanInfo(Class<?> beanClass, Class<?> stopClass) Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class.
static BeanInfo	getBeanInfo(Class<?> beanClass, int flags) Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class.
static String[]	getBeanInfoSearchPath() Gets an array of search packages.
static void	setBeanInfoSearchPath(String[] path) Sets the search packages.

Methods inherited from class java.lang.Object

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

Field Detail

IGNORE_ALL_BEANINFO

public static final int IGNORE_ALL_BEANINFO

Constant values to indicate that the Introspector will ignore all BeanInfo class.

See Also:

Constant Field Values

IGNORE_IMMEDIATE_BEANINFO

public static final int IGNORE_IMMEDIATE_BEANINFO

Constant values to indicate that the Introspector will ignore the BeanInfo class of the current bean class.

See Also:

Constant Field Values

USE_ALL_BEANINFO

public static final int USE_ALL_BEANINFO

Constant values to indicate that the Introspector will use all BeanInfo class which have been found. This is the default one.

See Also:

Constant Field Values

Method Detail

decapitalize

public static String decapitalize(String name)

Decapitalizes a given string according to the rule:

• If the first or only character is Upper Case, it is made Lower Case
• UNLESS the second character is also Upper Case, when the String is returned unchanged

  Parameters:

  name - - the String to decapitalize

  Returns:

  the decapitalized version of the String

flushCaches

public static void flushCaches()

Flushes all BeanInfo caches.

flushFromCaches

public static void flushFromCaches(Class<?> clazz)

Flushes the BeanInfo caches of the specified bean class

Parameters:

clazz - the specified bean class

getBeanInfo

public static BeanInfo getBeanInfo(Class<?> beanClass)
                            throws IntrospectionException

Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class.

The Introspector will cache the BeanInfo object. Subsequent calls to this method will be answered with the cached data.

Parameters:

beanClass - the specified bean class.

Returns:

the BeanInfo of the bean class.

Throws:

IntrospectionException

getBeanInfo

public static BeanInfo getBeanInfo(Class<?> beanClass,
                                   Class<?> stopClass)
                            throws IntrospectionException

Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class. It will not introspect the "stopclass" and its super class.

The Introspector will cache the BeanInfo object. Subsequent calls to this method will be answered with the cached data.

Parameters:

beanClass - the specified beanClass.

stopClass - the sopt class which should be super class of the bean class. May be null.

Returns:

the BeanInfo of the bean class.

Throws:

IntrospectionException

getBeanInfo

public static BeanInfo getBeanInfo(Class<?> beanClass,
                                   int flags)
                            throws IntrospectionException

Gets the BeanInfo object which contains the information of the properties, events and methods of the specified bean class.

1. If flag==IGNORE_ALL_BEANINFO, the Introspector will ignore all BeanInfo class.
2. If flag==IGNORE_IMMEDIATE_BEANINFO, the Introspector will ignore the BeanInfo class of the current bean class.
3. If flag==USE_ALL_BEANINFO, the Introspector will use all BeanInfo class which have been found.

The Introspector will cache the BeanInfo object. Subsequent calls to this method will be answered with the cached data.

Parameters:

beanClass - the specified bean class.

flags - the flag to control the usage of the explicit BeanInfo class.

Returns:

the BeanInfo of the bean class.

Throws:

IntrospectionException

getBeanInfoSearchPath

public static String[] getBeanInfoSearchPath()

Gets an array of search packages.

Returns:

an array of search packages.

setBeanInfoSearchPath

public static void setBeanInfoSearchPath(String[] path)

Sets the search packages.

Parameters:

path - the new search packages to be set.