java 之类对象等于对象

/*
 * 使per2等于per1，其实是引用，当改变per2的属性时，实质上是改变了per2,per1所共同指向的堆内存里的数据。
 */
package StringClass;

/**
 *
 * @author zendao
 */
public class CopyAClass {

    public static void main(String args[]) {
        NewPeople per1 = new NewPeople("lucy", 22); // declare two entity
        NewPeople per2;
        per2 = per1; // per2 equal per1
        per2.setName("James");  // change the attribute of per2
        per1.getInfo();   // display and check the result
        per2.getInfo();
    }
}

/**
 * test class
 *
 * @author zendao
 */
class NewPeople {

    private String name;  // define test attributes
    private int age;

    /**
     * a constructor
     * @param name
     * @param age 
     */
    public NewPeople(String name, int age) {
        this.name = name;
        this.age = age;
    }

    /**
     * this method for printing the result
     * @return 
     */
    public String getInfo() {
        System.out.println("Name of this is :" + this.name + ",and age is :" + this.age);
        return null;
    }

    /**
     * this method is for change the attribute
     * @param name 
     */
    public void setName(String name) {
        this.name = name;
    }
}