Immutable 模式

参考书目《图解Java多线程设计模式》 [日] 结城浩 著

0. 描述了什么事？

一个实例产生后就不发生变化了。

1. 类的说明，如何抽象？

2. 程序示例

1. Main.java

package immutable;

public class Main {
    public static void main(String[] args) {
        Person alice = new Person("Alice", "Alaska");
        new PrintPersonThread(alice).start();
        new PrintPersonThread(alice).start();
        new PrintPersonThread(alice).start();
    }
}

2. Person.java

package immutable;

public final class Person {
    private final String name;
    private final String address;

    public Person(String name, String address) {
        this.name = name;
        this.address = address;
    }

    public String getName() {
        return name;
    }

    public String getAddress() {
        return address;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", address='" + address + '\'' +
                '}';
    }
}

3. PrintPersonThread.java

package immutable;

public class PrintPersonThread extends Thread {
    private Person person;

    public PrintPersonThread(Person person) {
        this.person = person;
    }

    @Override
    public void run() {
        while (true) {
            System.out.println(Thread.currentThread().getName() + " Print " + person);
        }
    }
}