jackson的使用

1. 导包

   <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-databind</artifactId>
       <version>2.10.1</version>
   </dependency>

2. 处理乱码

3. json解析

   //@Controller
   @RestController//不经过视图解析器,return字符串
   public class UserController {
       @RequestMapping("/json1")
       //@ResponseBody//不经过视图解析器,return字符串
       public String json1() throws JsonProcessingException {
           //jackson - ObjectMapper
           ObjectMapper mapper = new ObjectMapper();
           User user = new User("大头儿子", 6, "男");
           String string = mapper.writeValueAsString(user);
           return string;
       }
   
       @RequestMapping("/json2")
       //队列
       public String json2() throws JsonProcessingException {
           ObjectMapper mapper = new ObjectMapper();
           List<User> userList = new ArrayList<User>();
           User user1 = new User("大头儿子", 6, "男");
           User user2 = new User("也是大头儿子", 6, "男");
           User user3 = new User("还是大头儿子", 6, "男");
           User user4 = new User("不是大头儿子", 6, "女");
           userList.add(user1);
           userList.add(user2);
           userList.add(user3);
           userList.add(user4);
           String users = mapper.writeValueAsString(userList);
           return users;
       }
   
       @RequestMapping("/json3")
       //时间
       public String json3() throws JsonProcessingException {
           ObjectMapper mapper = new ObjectMapper();
           Date oridate = new Date();
           //通过java格式化时间
           SimpleDateFormat format = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
           String date = format.format(oridate);
           String obj = mapper.writeValueAsString(date);
           return obj;
       }
   
       @RequestMapping("/json4")
       public String json4() throws JsonProcessingException {
           ObjectMapper mapper = new ObjectMapper();
           Date oridate = new Date();
           //不使用时间戳的方式
           mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
           //自定义时间格式
           SimpleDateFormat format = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
           mapper.setDateFormat(format);
           String obj = mapper.writeValueAsString(oridate);
           return obj;
       }
   
       @RequestMapping("/json5")
       public String json5() throws JsonProcessingException {
           Date oridate = new Date();
           //使用自建工具类
           String obj = JsonUtils.getJson(oridate);
           return obj;
       }
   
   
       @RequestMapping("/json6")
       //队列
       public String json6() throws JsonProcessingException {
           List<User> userList = new ArrayList<User>();
           User user1 = new User("大头儿子", 6, "男");
           User user2 = new User("也是大头儿子", 6, "男");
           User user3 = new User("还是大头儿子", 6, "男");
           User user4 = new User("不是大头儿子", 6, "女");
           userList.add(user1);
           userList.add(user2);
           userList.add(user3);
           userList.add(user4);
           //使用自建工具类
           String users = JsonUtils.getJson(userList);
           return users;
       }

4. 自建工具类

   public class JsonUtils {
       public static String getJson(Object object) {
           return getJson(object, "yy-MM-dd HH:mm:ss");
       }
       public static String getJson(Object object, String dateformat) {
           ObjectMapper mapper = new ObjectMapper();
           mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
           SimpleDateFormat format = new SimpleDateFormat(dateformat);
           mapper.setDateFormat(format);
           try {
               return mapper.writeValueAsString(object);
           } catch (JsonProcessingException e) {
               e.printStackTrace();
           }
           return null;
       }
   }

原文：https://www.cnblogs.com/pinked/p/12230005.html