导入JackJSON包

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.12.1</version>
    </dependency>

json 数据中文乱码 在springMVC中配置

<mvc:annotation-driven>
                <mvc:message-converters>
                        <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                                <constructor-arg value="UTF-8" />
                        </bean>
                        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                                <property name="objectMapper">
                                        <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                                                <property name="failOnEmptyBeans" value="false" />
                                        </bean>
                                </property>
                        </bean>
                </mvc:message-converters>
        </mvc:annotation-driven>

用jackJson转json的类

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

import java.text.SimpleDateFormat;

/**
 * @Description:
 * @ClassName: jsonUtil
 * @Date: 2021/3/31 10:54
 * @Author: bm
 * @Version: 1.0
 * @Since: JDK 1.8
 */
public class JsonUtil {

    public static String getJson(Object object){
        return getJson(object,"yyyy-MM-dd HH:mm:ss");
    }

    public static String getJson(Object object, String dateFormat){
        ObjectMapper mapper = new ObjectMapper();

//不使用时间戳而是使用自己的格式        mapper.configure(SerializationFeature.WRITE_DATE_KEYS_AS_TIMESTAMPS,false);
        SimpleDateFormat ft = new SimpleDateFormat(dateFormat);
        try {
            return mapper.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }
}

调用工具类

import com.tv189.entity.User;
import com.tv189.utils.JsonUtil;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.List;

/**
 * @Description:
 * @ClassName: UserController
 * @Date: 2021/3/31 10:51
 * @Author: bm
 * @Version: 1.0
 * @Since: JDK 1.8
 */
@Controller
public class UserController {

    @RequestMapping("/test1")
    @ResponseBody
    public String json(){
        List<User> userList = new ArrayList<>();
        User user1 = new User("1号",2,"男");
        User user2 = new User("2号",3,"nv");
        userList.add(user1);
        userList.add(user2);
        return JsonUtil.getJson(userList);
    }
}