jdk的PropertyChangeSupport属性值修改的观察者模式应用
import java.beans.PropertyChangeEvent;import java.beans.PropertyChangeListener;import java.beans.PropertyChangeSupport;public class PropertyChangeSupportTest {static TestBean testBean = new TestBean();public static void main(String[] args) {PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(testBean);propertyChangeSupport.addPropertyChangeListener(new PropertyChangeListener(){@Overridepublic void propertyChange(PropertyChangeEvent evt) {if(evt.getPropertyName().equals("name")){System.out.println("bean:" + PropertyChangeSupportTest.this.testBean + " field:" + evt.getPropertyName() + " value change,old value:" + evt.getOldValue() + " new value:" + evt.getNewValue());}}});testBean.setId(111);testBean.setName("mike");propertyChangeSupport.firePropertyChange("name","","mike"); //通知该属性值做了修改，通知相关listener进行处理}public static class TestBean{private int id;private String name;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}}这是观察者模式的jdk应用场景，在我们平常的项目中，比如为了做到应用配置的动态加载，我们在应用启动后动态修改应用的一些配置参数时，需要通知相关应用了这个参数的应用点做出相应的变化，那么就可以用这个PropertyChangeSupport来完成。