package Object.reference; public class People {     private String name;     private int age;     public People(){     }     public People(String name, int age) {         super();         this.name = name;         this.age = age;     }     public String toString(){         return "name:" + name + " age:" + age;     }     public String getName() {         return name;     }     public int getAge() {         return age;     }     public void setName(String name) {         this.name = name;     }     public void setAge(int age) {         this.age = age;     } }

package Object.reference; /*  java 中的值传递和引用传递     http://www.1sucai.cn/clara/archive/2011/09/17/2179493.html     java 中没有引用传递，都是值传递的 */ public class Test {     public static void swap(People a, People b, boolean flag) {         if (flag) {             // 可以通过传递副本修改对象的值             a.setName("changeName");             a.setAge(100);         } else {             //副本交换，并不影响主程序的指针             People c = a;             a = b;             b = c;         }     }     public static void main(String[] args) {         People p1 = new People("yingjie", 23);         People p2 = new People("yuexin", 20);         swap(p1, p2,false);//传递的是p1,p2的副本，函数调用前后p1,p2没任何改变         swap(p1, p2,true);//传递的是p1,p2的副本，可以通过传递副本修改对象的值,函数调用前后p1对象内容改变     } }