JAVA.BEANS 包

property类和listener类，vetoable change event类和listener类在应用程序运行时被bean调用，用于建立用户接口，bean的descriptor 可通过bean-infos和introspection得到，

 

Basic.java

package chapter1;

import java.beans.PropertyChangeListener;

import java.beans.PropertyChangeSupport;

import java.beans.PropertyVetoException;

import java.beans.VetoableChangeListener;

import java.beans.VetoableChangeSupport;

import java.io.Serializable;

public class BasicBean {

   boolean property;

   int myProperty; 

 

   public int getMyProperty()

   {

  return myProperty;

   }

 

   public void setMyProperty(int newValue) throws PropertyVetoException

   {try{

   int oldValue=myProperty;

   myProperty=newValue;

   pceListeners.fireVetoableChange("myProperty",new Integer(oldValue),new Integer(newValue));

      }catch(PropertyVetoException e){

      throw e;

      }

   }

 

   //Create the listener list

   VetoableChangeSupport pceListeners= new VetoableChangeSupport(this);

 

   //The listener wrapper list

   public synchronized void addVetoPropertyChangeListener(VetoableChangeListener listener)

   {

  pceListeners.addVetoableChangeListener(listener);

   }

 

   public synchronized void removeVetoPropertyChangeListener(VetoableChangeListener listener)

   {

  pceListeners.removeVetoableChangeListener(listener);

   }

 

 

   public BasicBean()

   {

   }

   public boolean getProperty()

   {

  return property;

   }

   public boolean isProperty()

   {

  return property;

   }

   public void setProperty(boolean newValue)

   {

   property=newValue;

   }

}

Instantiate.java

package chapter1;

import java.beans.BeanInfo;

import java.beans.Beans;

import java.beans.Expression;

import java.beans.Introspector;

import java.beans.PropertyDescriptor;

import java.beans.Statement;

import java.io.IOException;

public class Instantiate {

public static void main(String[] args) 

{   Object o = new MyBean();

    try{

     Expression expr = new Expression(o,"getProp1",new Object[0]);

     expr.execute();

     String s =(String)expr.getValue();

     Statement stmt = new Statement(o,"setProp1",new Object[]{"new string"});

     stmt.execute();

        expr = new Expression(o,"getProp2",new Object[0]);

     expr.execute();

     int i =(Integer)expr.getValue();

        stmt = new Statement(o,"setProp2",new Object[]{new Integer(123)});

     stmt.execute();

     expr = new Expression(o,"getProp3",new Object[0]);

       expr.execute();

       int i =(Integer)expr.getValue();

          stmt = new Statement(o,"setProp3",new Object[]{new byte[]{0x12,0x23}});

       stmt.execute();

    }catch(Exception e){}

try

{

        BasicBean bean = (BasicBean)Beans.instantiate(ClassLoader.getSystemClassLoader(), "MyBeans");  

} catch(ClassNotFoundException e){

}catch(IOException e){}

try{

BeanInfo bi = Introspector.getBeanInfo(MyBean.class);

PropertyDescriptor[] pds=bi.getPropertyDescriptors();

for(int i=0;i<pds.length;i++)

{

String propName = pds[i].getName();

}

}

}

}

MyBean.java

package chapter1;

public class MyBean {

String prop1;

int prop2;

public String getProp1(){

return prop1;

}

public void setProp1(String s){

prop1=s;

}

public int getProp2(){

     return prop2;

}

public void setProp2(int i){

   prop2=i;

}

byte[] prop3;

public byte[] getProp3(){

return prop3;

}

public void setPROP3(byte[] bytes){

prop3=bytes;

}

}