public class Person { 
  private String name; 
 
  Person(String name){ 
    this.name = name; 
  } 
   
  public String getName() { 
    return name; 
  } 
 
  public void setName(String name) { 
    this.name = name; 
  } 
} 
 
public class FinalTest { 
  private final String final_01 = "chenssy";  //编译期常量，必须要进行初始化，且不可更改 
  private final String final_02;        //构造器常量，在实例化一个对象时被初始化 
   
  private static Random random = new Random(); 
  private final int final_03 = random.nextInt(50);  //使用随机数来进行初始化 
   
  //引用 
  public final Person final_04 = new Person("chen_ssy");  //final指向引用数据类型 
   
  FinalTest(String final_02){ 
    this.final_02 = final_02; 
  } 
   
  public String toString(){ 
    return "final_01 = " + final_01 +"  final_02 = " + final_02 + "  final_03 = " + final_03 + 
        "  final_04 = " + final_04.getName(); 
  } 
   
  public static void main(String[] args) { 
    System.out.println("------------第一次创建对象------------"); 
    FinalTest final1 = new FinalTest("cm"); 
    System.out.println(final1); 
    System.out.println("------------第二次创建对象------------"); 
    FinalTest final2 = new FinalTest("zj"); 
    System.out.println(final2); 
    System.out.println("------------修改引用对象--------------"); 
    final2.final_04.setName("chenssy"); 
    System.out.println(final2); 
  } 
} 
 
------------------ 
Output: 
------------第一次创建对象------------ 
final_01 = chenssy  final_02 = cm  final_03 = 34  final_04 = chen_ssy 
------------第二次创建对象------------ 
final_01 = chenssy  final_02 = zj  final_03 = 46  final_04 = chen_ssy 
------------修改引用对象-------------- 
final_01 = chenssy  final_02 = zj  final_03 = 46  final_04 = chenssy 

public class Custom extends Person{ 
  public void method1(){ 
    System.out.println("Person's method1...."); 
  } 
   
//  Cannot override the final method from person：子类不能覆盖父类的final方法 
//  public void method2(){ 
//    System.out.println("Person's method2..."); 
//  } 
} 

public class Custom { 
  public void test(final int i){ 
   //i++;   ---final参数不可改变 
    System.out.println(i); 
  } 
   
  public void test(final Person p){ 
   //p = new Person();  --final参数不可变 
   p.setName("chenssy"); 
  } 
}