fastJson和JackSon的区别

public class JsonTest {
  //准备存放了一个对象的json字符串
  private String userStr = "{\"id\":1,\"name\":\"简溪\",\"birthday\":\"2010-01-01\"}";
//准备存放了一个集合的json字符串
private String userArr = "[{\"id\":1,\"name\":\"简溪\",\"birthday\":\"2010-01-01\"},"+ "{\"id\":2,\"name\":\"顾里\",\"birthday\":\"2012-08-01\"}]";
private User user;
private List<User> users = new ArrayList<User>();
@Before
public void initUser() {
  //初始化一个用户
  User user = new User();
  user.setId(1);
  user.setName("林萧");
  user.setBirthday(new Date());
  this.user = user;
  //初始化一个集合
  User user1 = new User();
  user1.setId(1);
  user1.setName("林萧");
  user1.setBirthday(new Date());
  users.add(user1);
  User user2 = new User();
  user2.setId(2);
  user2.setName("顾源");
  user2.setBirthday(new Date());
  users.add(user2);
}
//fastjson
@Test
public void fastjson_json2Bean() {
  //[1-1] 对象格式json串转对象
  User user = JSONObject.parseObject(userStr, User.class);
  System.out.println(user);
  //打印效果如下：
  //User [id=1, name=简溪, birthday=2010-01-01]
  //[1-2] 集合格式json串转对象
  List<User> users = JSONArray.parseArray(userArr, User.class);
  System.out.println(users);
  //打印效果如下：
  //      [User [id=1, name=简溪, birthday=2010-01-01], User [id=2, name=顾里, birthday=2012-08-01]]
}
@Test
public void fastjson_bean2Json() {
  //[1-3] 对象转json串
  String userJson = JSONObject.toJSONString(user);
  System.out.println(userJson);
  //打印效果如下：
  //      {"birthday":1530716739741,"id":1,"name":"林萧"}
  //[1-4] 集合转json串
  String usersStr = JSONArray.toJSONString(users);
  System.out.println(usersStr);
  //打印效果如下：
  //      [{"birthday":1530716739741,"id":1,"name":"林萧"},{"birthday":1530716739741,"id":2,"name":"顾源"}]
}
//jackson
@Test
public void jackson_json2Bean() throws Exception {
  //[2-1] 对象格式json串转对象
  ObjectMapper jackson = new ObjectMapper();
  User user = jackson.readValue(userStr, User.class);
  System.out.println(user);
  //打印结果
  //User [id=1, name=简溪, birthday=2010-01-01]
  //[2-2 对象格式json串转对象
  List<User> users = jackson.readValue(userArr, new TypeReference<List<User>>() {});
  System.out.println(users);
  //打印结果
    //[User [id=1, name=简溪, birthday=2010-01-01], User [id=2, name=顾里, birthday=2012-08-01]]
}
  @Test
public void jackson_bean2Json() throws Exception {
  ObjectMapper jackson = new ObjectMapper();
  //[2-3] 对象转json串
  String userJson = jackson.writeValueAsString(user);
  System.out.println(userJson);
  //打印结果
  //      {"id":1,"name":"林萧","birthday":1530717373507}
  //[2-4] 集合转json串
  String usersJson = jackson.writeValueAsString(users);
  System.out.println(usersJson);
  //打印结果
  //      [{"id":1,"name":"林萧","birthday":1530717401460},{"id":2,"name":"顾源","birthday":1530717401460}]
}
}