jdk13新特性 | 一代天骄's BLOG

2019年09月17日，JCP如期半年一更的约定，jdk迎来了新的版本jdk13.这里记录下新特性中比较亮眼的2个特性，方便后续查阅。详细的新特性参考jdk13。

text block 省去了很多转义

   @Test 
   public void textBlock(){
       String sql = """
                select * from system_user
                where user_id = '543255'
                and age >12
                and birth>'1991'
        """;

        String html = """
  ..............<html>
  ..............    <body>
  ..............        <p>Hello, world</p>
  ..............    </body>
  ..............</html>
  ..............""";

        System.out.println(html);
        System.out.println(sql);
    }

增强switch,支持yield设置返回

  /**
   * jdk12
   * @throws IOException
   */
  @Test
  public void switchFeature() throws IOException {
      switch ("A") {
          case "A" -> System.out.println("you is A");
          case "B" -> System.out.println("you is B");
      }
  }

  /**
   * jdk13
   * @throws IOException
   */
  @Test
  public void switchFeature2() throws IOException {
      String a = "A";
     var result =  switch (a) {
         case "A" :yield "1";
         case "B": yield "2";
         default:
             throw new IllegalStateException("Unexpected value: " + a);
     };
     System.out.println(result);
  }