Java Generics 简明教程

Java Generics - Multiple Type Parameters

泛型类可以有多个类型参数。以下示例將展示上述概念。

A Generic class can have muliple type parameters. Following example will showcase above mentioned concept.

Example

使用任意你选择的编辑器创建以下 Java 程序。

Create the following java program using any editor of your choice.

GenericsTester.java

package com.tutorialspoint;

public class GenericsTester {
   public static void main(String[] args) {
      Box<Integer, String> box = new Box<Integer, String>();
      box.add(Integer.valueOf(10),"Hello World");
      System.out.printf("Integer Value :%d\n", box.getFirst());
      System.out.printf("String Value :%s\n", box.getSecond());

      Box<String, String> box1 = new Box<String, String>();
      box1.add("Message","Hello World");
      System.out.printf("String Value :%s\n", box1.getFirst());
      System.out.printf("String Value :%s\n", box1.getSecond());
   }
}

class Box<T, S> {
   private T t;
   private S s;

   public void add(T t, S s) {
      this.t = t;
      this.s = s;
   }

   public T getFirst() {
      return t;
   }

   public S getSecond() {
      return s;
   }
}

这将产生以下结果。

This will produce the following result.

Output

Integer Value :10
String Value :Hello World
String Value :Message
String Value :Hello World