jackson:POJO和map互转

背景

有个场景就是要把pojo转成map<String,Object>，用于展示，但是自己写的感觉太丑了，一个pojo就得写一个。
比如下面这样

image.png

想看看怎么改进

jackson的支持

参照refer，发现jackson是支持pojo和map互转的(之前只是看前辈用过，以为只是和json String互相转换用的，结果发现jackson功能太强大了，可以参照知乎的refer

pojo和map转换的demo

非常简单

public class Main {
    static class Student {
        @JsonIgnore
        private String name;
        @JsonIgnore
        private int age;
        private List<String> skills;
        // getters setters

        public String getName() {
            return name;
        }

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

        public int getAge() {
            return age;
        }

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

        public List<String> getSkills() {
            return skills;
        }

        public void setSkills(List<String> skills) {
            this.skills = skills;
        }
    }
    public static void main(String[] args) {
        ObjectMapper oMapper = new ObjectMapper();

        Student obj = new Student();
        obj.setName("asd");
        obj.setAge(34);
        obj.setSkills(Arrays.asList("zxc","h"));

        // object -> Map
        Map<String, Object> map = oMapper.convertValue(obj, Map.class);
        System.out.println(map);
    }
}

输出如下
因为其他属性都被JsonIgnore了

{skills=[zxc, h]}

思考

后续可以看看jackson源码，不过现在rocketmq源码都block住了

refer

https://www.mkyong.com/java/java-convert-object-to-map-example/
https://stackoverflow.com/questions/35848506/how-to-convert-not-all-attributes-from-a-java-object-to-json-using-jackson-objec
https://stackoverflow.com/questions/11757487/how-to-tell-jackson-to-ignore-a-field-during-serialization-if-its-value-is-null 忽略属性值为null的
http://www.makeinjava.com/convert-list-objects-tofrom-json-java-jackson-objectmapper-example/ list和string互转
https://www.zhihu.com/question/44199956 和fastjson比较
http://vickyqi.com/2015/10/19/%E5%87%A0%E7%A7%8D%E5%B8%B8%E7%94%A8JSON%E5%BA%93%E6%80%A7%E8%83%BD%E6%AF%94%E8%BE%83/ 性能比较
http://jackson.codehaus.org/ 官网
https://github.com/FasterXML 源码