Java基础属性监听器

创建实体类

public class Student {  
    private String name;  
    private int age;  
    // 添加属性监听器支持
    public PropertyChangeSupport pcs = new PropertyChangeSupport(this);  
    public Student() {  
    }  
    public Student(String name, int age) {  
        this.name = name;  
        this.age = age;  
    }  
    public String getName() {  
        return name;  
    }  
    public void setName(String name) {  
        String oldValue = this.name;  
        this.name = name;  
        // 属性发生变化时，用属性监听器绑定监听属性
        pcs.firePropertyChange("setName_pro", oldValue, this.name);  
    }  
    public int getAge() {  
        return age;  
    }  
    public void setAge(int age) {  
        int oldValue = this.age;  
        this.age = age;  
        // 属性发生变化时，用属性监听器绑定监听属性
        pcs.firePropertyChange("setAge_pro", oldValue, this.age);  
    }  
    @Override  
    public String toString() {  
        return "Student{" +  
            "name='" + name + '\'' +  
            ", age=" + age +  
            '}';  
    }
}

创建学生类并初始化Student student = new Student("reine", 18);

创建按钮并绑定事件用于修改学生属性

Button button = new Button("修改数据");
anchorPane.getChildren().addAll(button);
button.setOnAction(event -> {  
    student.setName("reine2");  
    student.setAge(19);  
});

监听学生所有属性值改变

student.pcs.addPropertyChangeListener(new PropertyChangeListener() {  
    @Override  
    public void propertyChange(PropertyChangeEvent e) {  
        System.out.println(e.getPropertyName() + ": " + e.getOldValue() + " -> " + e.getNewValue());  
    }  
});

setName_pro: reine -> reine2
setAge_pro: 18 -> 19

监听学生单个属性值改变

student.pcs.addPropertyChangeListener("setName_pro", new PropertyChangeListener() {  
    @Override  
    public void propertyChange(PropertyChangeEvent e) {  
        System.out.println("setName_pro: " + e.getOldValue() + " -> " + e.getNewValue());  
        System.out.println("e.getSource() = " + e.getSource());  
    }  
});

setName_pro: reine -> reine2
e.getSource() = Student{name='reine2', age=18}

# Java基础属性监听器

Java基础属性监听器