1.jackson常用注解

https://github.com/FasterXML/jackson-annotations
@JsonInclude
@JsonIgnor
@JsonFormat
@JsonProperty

@JsonInclude(JsonInclude.Include.NON_NULL)//username为空时不返回
    private String username;
    //返回数据忽略pwd
    @JsonIgnore
    private String pwd;
    //指定日期格式
    @JsonFormat(pattern = "yyyy-MM-dd hh:mm:ss",locale = "zh",timezone = "GMT+8")
    private Date birthday;
    private int age;
    private int id;
    //指定别名---应用场景返回数据不想让其知道意义
    @JsonProperty("telephone")
    private String phone;

json:
{“birthday”:“2020-02-11 04:14:28”,“age”:19,“id”:1,“telephone”:“13699466368”}

注：更多注解详情可参考https://blog.csdn.net/zhouyecheng/article/details/79562425

2.Jackson序列化与反序列化

pojo:

public class Student {

    @JsonInclude(JsonInclude.Include.NON_NULL)
    private String username;

    //返回数据忽略pwd
    @JsonIgnore
    private String pwd;
    //指定日期格式
    @JsonFormat(pattern = "yyyy-MM-dd hh:mm:ss",locale = "zh",timezone = "GMT+8")
    private Date birthday;
    private int age;
    private int id;
    //指定别名---应用场景返回数据不想让其知道意义
    @JsonProperty("telephone")
    private String phone;


    public Date getBirthday()
    {
        return this.birthday;
    }
    public void setBirthday(Date birthday)
    {
        this.birthday=birthday;
    }
    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }


    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    public int getAge() {
        return age;
    }

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

    public int getId() {
        return id;
    }

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

//jackson
    @org.junit.Test
    public void TestJackSon() throws Exception
    {
   		 //用map对象存储
        Map<String, Object> map = new HashMap<>(16);
        String s = "{\"id\": 1,\"name\": \"小明\",\"array\": [\"1\", \"2\"]," +
                "\"test\":\"I'm test\",\"base\": {\"major\": \"物联网\",\"class\": \"3\"}}";

        ObjectMapper mapper=new ObjectMapper();
        map = mapper.readValue(s, map.getClass());
        //获取id
        Integer studentId = (Integer) map.get("id");

        System.out.println(map.get("name"));
        System.out.println(map.get("array").toString());
        System.out.println(studentId);
//****************************************************************************************************************************
			//student对象Json字符串
        String s2="{\"birthday\":\"2020-02-11 03:29:11\",\"age\":19,\"id\":1,\"telephone\":\"13699466368\"}";
        Student stu=new Student();
        stu= mapper.readValue(s1, stu.getClass());
        System.out.println(stu.getUsername()+stu.getPhone()+stu.getBirthday());
        String s2 = mapper.writeValueAsString(stu);
        System.out.println(s2);


    }

输出：