System.out.println(对象)

 class Person {
     private String name;
     private int age;
     public String getName() {
         return this.name;
     }

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

     public int getAge() {
         return this.age;
     }

     public void setAge(int age) {
         this.age = age;
     }

     public int getAge() {
         return this.age;
     }

     public String toString() {
         return "姓名: " + this.name + ", 年龄: " + this.age;
     }
 }

 public class InstanceDemo01 {
     public static void main(String args[]) {
         Class<?> c = null;
         try {
             c = Class.forName("Person");
         } catch(ClassNotFoundException e) {
             e.printStackTrace();
         }

         Person per = null;
         try {
             per = (Person)c.newInstance();    // 实例化Person对象
         } catch(Exception e) {
             e.printStackTrace();
         }

         per.setName("李兴华");
         per.setAge(30);
         System.out.println(per);            // 内容输出: 调用toString()
     }
 }