Package javaa.beans

Class Introspector

java.lang.Object
javaa.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

    Fields
    Modifier and Type
    Field
    Description
    static final int
    IGNORE_ALL_BEANINFO
    Constant values to indicate that the Introspector will ignore all BeanInfo class.
    static final int
    IGNORE_IMMEDIATE_BEANINFO
    Constant values to indicate that the Introspector will ignore the BeanInfo class of the current bean class.
    static final int
    USE_ALL_BEANINFO
    Constant values to indicate that the Introspector will use all BeanInfo class which have been found.

  • Method Summary

    Modifier and Type
    Method
    Description
    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, int flags)
    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 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 Details

    • IGNORE_ALL_BEANINFO

      public static final int IGNORE_ALL_BEANINFO
      Constant values to indicate that the Introspector will ignore all BeanInfo class.
      See Also:

    • 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:

    • 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:

  • Method Details

    • 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.