SpringMVC入门-jackson

SpringMVC入门-jackson

1.导入坐标pom.xml

<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.13.3</version>
 </dependency>

2.springmvc-servlet.xml 中文乱码解决

<!--JSON中文乱码解决-->
    <mvcc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF8"/>
            </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>
    </mvcc:annotation-driven>

3.创建实体类 User

public class User {
    private int id;
    private String name;
    private int age;

    public User() {
    }
    
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public User(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
}

4.创建测试类

package com.itcast.controller;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.itcast.pojo.User;
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;

@Controller
public class ControllerJson {

    @RequestMapping("/h2")
    @ResponseBody
    public String test2() throws JsonProcessingException {
        //json
        ObjectMapper mapper = new ObjectMapper();
        //创建几何
        List list = new ArrayList<>();
        //创建对象
        User u1 = new User(1,"小明",20);
        User u2 = new User(2,"小李",20);
        User u3 = new User(3,"小刘",20);

        //添加
        list.add(u1);
        list.add(u2);
        list.add(u3);

        //json
        String json = mapper.writeValueAsString(list);
        return json;
    }
}

5.测试
注意：
1.建议Tomcat版本采用9的