Introspector JDK 1.6)

Description

public class Introspector

The Introspector class provides a standard way for tools to learn about the properties, events, and methods supported by a target Java Bean.

For each of those three kinds of information, the Introspector will separately analyze the bean's class and superclasses looking for either explicit or implicit information and use that information to build a BeanInfo object that comprehensively describes the target bean.

For each class "Foo", explicit information may be available if there exists a corresponding "FooBeanInfo" class that provides a non-null value when queried for the information. We first look for the BeanInfo class by taking the full package-qualified name of the target bean class and appending "BeanInfo" to form a new class name. If this fails, then we take the final classname component of this name, and look for that class in each of the packages specified in the BeanInfo package search path.

Thus for a class such as "sun.xyz.OurButton" we would first look for a BeanInfo class called "sun.xyz.OurButtonBeanInfo" and if that failed we'd look in each package in the BeanInfo search path for an OurButtonBeanInfo class. With the default search path, this would mean looking for "sun.beans.infos.OurButtonBeanInfo".

If a class provides explicit BeanInfo about itself then we add that to the BeanInfo information we obtained from analyzing any derived classes, but we regard the explicit information as being definitive for the current class and its base classes, and do not proceed any further up the superclass chain.

If we don't find explicit BeanInfo on a class, we use low-level reflection to study the methods of the class and apply standard design patterns to identify property accessors, event sources, or public methods. We then proceed to analyze the class's superclass and add in the information from it (and possibly on up the superclass chain).

Because the Introspector caches BeanInfo classes for better performance, take care if you use it in an application that uses multiple class loaders. In general, when you destroy a ClassLoader that has been used to introspect classes, you should use the Introspector.flushCaches or Introspector.flushFromCaches method to flush all of the introspected classes out of the cache.

For more information about introspection and design patterns, please consult the JavaBeans specification.

See also:

Methods

Hide/Show inherited methods

publicstatic String decapitalize (String name)

Utility method to take a string and convert it to normal Java variable name capitalization.

pack-privatestatic Method findMethod (Class cls, String methodName, int argCount)

Find a target methodName on a given class.

pack-privatestatic Method findMethod (Class cls, String methodName, int argCount, Class args)

Find a target methodName with specific parameter list on a given class.

publicstatic void flushCaches ()

Flush all of the Introspector's internal caches.

publicstatic void flushFromCaches (Class<Object> clz)

Flush the Introspector's internal cached information for a given class.

publicstatic BeanInfo getBeanInfo (Class<Object> beanClass) throws IntrospectionException

Introspect on a Java Bean and learn about all its properties, exposed methods, and events.

publicstatic BeanInfo getBeanInfo (Class<Object> beanClass, Class<Object> stopClass) throws IntrospectionException

Introspect on a Java bean and learn all about its properties, exposed methods, below a given "stop" point.

publicstatic BeanInfo getBeanInfo (Class<Object> beanClass, int flags) throws IntrospectionException

Introspect on a Java bean and learn about all its properties, exposed methods, and events, subject to some control flags.

publicstaticsynchronized String getBeanInfoSearchPath ()

Gets the list of package names that will be used for finding BeanInfo classes.

pack-privatestatic Object instantiate (Class sibling, String className) throws InstantiationException IllegalAccessException ClassNotFoundException

Try to create an instance of a named class.

pack-privatestatic boolean isSubclass (Class a, Class b)

Return true if class a is either equivalent to class b, or if class a is a subclass of class b, i.e.

publicstaticsynchronized void setBeanInfoSearchPath (String path)

Change the list of package names that will be used for finding BeanInfo classes.