1. 导包

<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson  调用者需要转换-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.58</version>
</dependency>

2. 入门

  //对象转换为json字符串,json字符串转换java对象
  //JSONObject/JSONArray.toJSONString JSONObject.parseObject  JSONArray.parseArray
  @Test
  public void test() throws Exception{
     Person zs = new Person(1L, "zs");
      //单个对象--json对象
     String jsonObj = JSONObject.toJSONString(zs);
     System.out.println(jsonObj);
     //集合---json数组

     String jsonArray = JSONArray.
             toJSONString(Arrays.asList(zs, zs,
                     new Person(2L, "ls")));
     System.out.println(jsonArray);

     //json对象--单个对象
     Person person = JSONObject.parseObject(jsonObj, Person.class);
     System.out.println(person);
     //json数组--集合
     List<Person> persons = JSONArray.parseArray(jsonArray, Person.class);
     System.out.println(persons);
 }