1、实现Build步骤
1、创建实体类
2、创建实体内部build类
3、实体内部类返回实体类
4、实体类创建内部类构造函数
/**
* 作者:created by meixi
* 邮箱:[email protected]
* 日期:2018/12/14 11
*/
public class PersonBuildertest {
private String name;
private int idd;
public PersonBuildertest(Builder builder) {
this.name = builder.name;
this.idd = builder.idd;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getIdd() {
return idd;
}
public void setIdd(int idd) {
this.idd = idd;
}
public static class Builder {
private String name;
private int idd;
public Builder name(String namein) {
this.name = namein;
return this;
}
public Builder idd(int id){
this.idd =id;
return this;
}
public PersonBuildertest build(){
return new PersonBuildertest(this);
}
}
}
使用方法:
PersonBuildertest buildertest = builder.name("那么").idd(2).build();
Log.i("lgq","builertttt==="+buildertest.getName());
12-14 13:45:03.313 21756-21756/? I/lgq: builertttt===那么
2、原型模式
实现步骤
1、实现Cloneable接口
2、重写Object的clone方法
3、实现clone方法中的拷贝逻辑
public class Clonetest implements Cloneable{
private String name;
private int age;
public Clonetest(){
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public Object clone(){
Clonetest person=null;
try {
person=(Clonetest)super.clone();
person.name=this.name;
person.age=this.age;
} catch (CloneNotSupportedException e) {
e.printStackTrace();
}
return person;
}
}
使用方法
Clonetest p=new Clonetest();
p.setAge(18);
p.setName("张三");
Clonetest p1= (Clonetest) p.clone();
p1.setName("李四");
Log.i("lgq","builertttt==="+p1.getName()+"...."+p1.getAge());
12-14 13:45:03.313 21756-21756/? I/lgq: builertttt===李四....18
3、单例模式的实现步骤
1、静态实例
2、私有化构造方法
3、静态获取实例的函数,双重null判断synchronize同步处理——
使用synchronized 进行同步处理,并且双重判断是否为null,我们看到synchronized (Singleton.class)里面又进行了是否为null的判断,这是因为一个线程进入了该代码,如果另一个线程在等待,这时候前一个线程创建了一个实例出来完毕后,另一个线程获得锁进入该同步代码,实例已经存在,没必要再次创建,因此这个判断是否是null还是必须的。
public class Singleton {
private static volatile Singleton instance = null;
private Singleton(){
}
public static Singleton getInstance() {
if (instance == null) {
synchronized (Singleton.class) {
if (instance == null) {
instance = new Singleton();
}
}
}
return instance;
}
}
4、观察者模式
主要三个类
1、
public interface Observer {
void update(int id,String param);
}
2、
public interface Subject {
/**
* 注册一个观察者
*/
void addObserver(Observer observer);
/**
* 删除一个观察者
*
* @return 是否删除成功
*/
boolean removeObserver(Observer observer);
/**
* 通知所有的观察者
*
* @param id 对应观察者的id
*/
void notifyObserver(int id,String param);
}
3、
public class TestObServernotice implements Subject {
private static Subject subject;
private List<Observer> observers = new ArrayList<>();
private TestObServernotice() {
// TODO Auto-generated constructor stub
}
public static Subject getInstance() {
if (null == subject) {
synchronized (TestObServernotice.class) {
if (null == subject)
subject = new TestObServernotice();
}
}
return subject;
}
@Override
public void addObserver(Observer observer) {
// TODO Auto-generated method stub
observers.add(observer);
}
@Override
public boolean removeObserver(Observer observer) {
// TODO Auto-generated method stub
return observers.remove(observer);
}
@Override
public void notifyObserver(int id,String param) {
// TODO Auto-generated method stub
for (Observer observer : observers) {
observer.update(id,param);
}
}
}
观察者中注册Observer,如MainActivity中注册
private Observer deleteObserver = new Observer() {
@Override
public void update(int id,String param) {
tomapte.setText("sssssymd"+param);//dosomething
}
};
TestObServernotice.getInstance().addObserver(deleteObserver);
同时注意删除观察者
@Override
protected void onDestroy() {
super.onDestroy();
TestObServernotice.getInstance().removeObserver(deleteObserver);
deleteObserver = null;
Log.v("lgq", "......11..onDestroy....");
}
调用,通知观察者,主要在receiver中调用,fragment,activity都可以调用,跨界面刷新数据
TestObServernotice.getInstance().notifyObserver(0,bundle.getString("cn.jpush.android.ALERT"));
5、命令模式
实现步骤:
(1)创建命令接受者:
//命令接收者Receiver public class Tv { public int currentChannel = 0; public void turnOn() { System.out.println("lgqThe televisino is on."); } public void turnOff() { System.out.println("The television is off."); } public void changeChannel(int channel) { this.currentChannel = channel; System.out.println("Now TV channel is " + channel); } }
(2)定义命令的接口,声明执行的方法。
//执行命令的接口 public interface Command { void execute(); }
(3)命令接口实现对象
//开机命令ConcreteCommand,获取接受者类,实现命令 public class CommandOn implements Command { private Tv myTv; public CommandOn(Tv tv) { myTv = tv; } public void execute() { myTv.turnOn(); } }
(4)要求命令对象执行请求,通常会持有命令对象
//可以看作是遥控器Invoker public class Control { private Command onCommand, offCommand, changeChannel; public Control(Command on) { onCommand = on; } public void turnOn() { onCommand.execute(); } // public void turnOff() { // offCommand.execute(); // } // // public void changeChannel() { // changeChannel.execute(); // } }
(5)组装命令对象和接收者
// 命令接收者Receiver Tv myTv = new Tv(); // 开机命令ConcreteCommond CommandOn on = new CommandOn(myTv); // on.execute(); // 命令控制对象Invoker,组装接受者,命令对象 Control control = new Control(on); // 开机 control.turnOn();