Java 对象#clone 行为？

Question

我正在测试 Object#clone 方法的行为，但我不明白为什么以下代码会打印 true, Diego, Diego，自从 p.getName( ) == p2.getName() 打印为真。谁能解释一下为什么 p2.setName("Armando") 指向同一个字符串时不修改 p 对象？谢谢。

public class Main {

public static void main(String[] args) {
    Person p = new Person();
    p.setName("Diego");
    Person p2 = null;
    try {
         p2 = (Person) p.clonar();
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }
    System.out.println(p.getName() == p2.getName());
    System.out.println(p.getName());
    p2.setName("Armando");
    System.out.println(p.getName());
}
}

class Person implements Cloneable {
private String name;

public Object clonar() throws CloneNotSupportedException {
    return this.clone();
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}
}

Answer 1

因为那个时候两个引用都指向同一个String对象。但是，当您调用 p2.setName 时，p2 的名称引用将指向另一个 String 对象。 @dunni提供的答案

为了重现我想要的行为，我首先需要添加一个可变 class 作为占位符（地址）：

public class Main {

public static void main(String[] args) {
    Person p = new Person();
    Person p2 = null;
    Address address = new Address("paseo de la reforma");
    p.setAddress(address);

    try {
         p2 = (Person) p.clonar();
    } catch (CloneNotSupportedException e) {
        e.printStackTrace();
    }   
    p2.getAddress().setStreet("lomas de chapultepec");
    System.out.println(p.getAddress().getStreet());
}
}

class Address {
private String street;

public Address(String street) {
    this.street = street;
}

public String getStreet() {
    return street;
}

public void setStreet(String street) {
    this.street = street;
}

  }

class Person implements Cloneable {
private String name;
private Integer edad;
private int mes;
private Address address;

public Integer getEdad() {
    return edad;
}

public void setEdad(Integer edad) {
    this.edad = edad;
}

public int getMes() {
    return mes;
}

public void setMes(int mes) {
    this.mes = mes;
}

public Object clonar() throws CloneNotSupportedException {
    return this.clone();
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Address getAddress() {
    return address;
}

public void setAddress(Address address) {
    this.address = address;
}
}

现在打印：

改革大道

查普尔特佩克洛马斯

Java 对象#clone 行为？

Java Object#clone behavior?

java

clone