14. final关键字

public class FinalStringTest {

    public static void main(String[] args) {
        Person person1 = new Person("张三");
        System.out.println(person1);
        Person person2 = new Person("李四");
        System.out.println(person2);

        person2.clo.setCalled("高级衣服");
        System.out.println(person2);

    }
}

class Person{
    public final String name = "ddd";
    public final String trueName;

    private Random random = new Random();

    public final int rand = random.nextInt(50);

    public final cloth clo = new cloth("普通衣服");

    public Person(String trueName){
        this.trueName = trueName;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", trueName='" + trueName + '\'' +
                ", random=" + random +
                ", rand=" + rand +
                ", clo=" + clo.getCalled() +
                '}';
    }
}

class cloth{
    private String called;

    public String getCalled() {
        return called;
    }

    public void setCalled(String called) {
        this.called = called;
    }

    public cloth(String called){
        this.called = called;
    }
}

输出
Person{name=‘ddd’, trueName=‘张三’, random=java.util.Random@677327b6, rand=14, clo=普通衣服}
Person{name=‘ddd’, trueName=‘李四’, random=java.util.Random@14ae5a5, rand=19, clo=普通衣服}
Person{name=‘ddd’, trueName=‘李四’, random=java.util.Random@14ae5a5, rand=19, clo=高级衣服}