JSON

 详细：

https://www.cnblogs.com/LearnAndGet/p/10009646.html

//JSONObject解析字符串，转化为对象
CityPartnerDTO dto = JSONObject.parseObject(middlemanDTO.getBizInfo(), CityPartnerDTO.class);
//JSON把对象转化为String
JSON.toJSONString(ids)
 //利用JSON来查看，数据结构
public static void main(String[] args) {
    System.out.println(JSON.toJSONString(RULES));
}

数组可以用List来解析，因为Arraylist底层是数组

//数组转List
            List<String> openIdList= new ArrayList<>(Arrays.asList(data.getOpenidArray()));

对象嵌套的解析：

例如：

 {"code":0,"msg":"","data":[{"module":"接口测试","category_id":"560685e3738a18e0aaf47c1b454ce6b7","category_name":"测试分类","order_no":99,"children":[]}]}

//发送请求，接口返回结果解析为String
ResponseEntity<String> responseString = restTemplate.exchange(GETMENU_INTERFACE_URL, HttpMethod.GET, requestEntity, String.class);
String body = responseString.getBody();
if(StringUtils.isNotBlank(body)){
            //逐层解析
 　　　　JSONObject json = JSONObject.parseObject(body);  　　//对象解析为JSONObject
            String code = json.get("code").toString();
            String msg = json.get("msg").toString();

　　　　JSONArray data = json.getJSONArray("data");　　　　　　//data是一个数组，解析为JSONArray


            for (int i = 0; i < data.size(); i++) {   　　　　//遍历，得到数组里每一个对象
                String menu = data.getString(i);
                 JSONObject module2 = JSONObject.parseObject(menu); //对象解析为JSONObject
                String modulename = module2.getString("module");
                String category_id = module2.getString("category_id");
                String category_name = module2.getString("category_name");
                String order_no = module2.getString("order_no");
                String children = module2.getString("children");
　　　　　　}
　　}

结果：

简单点：fastJson的parseObject方法可以解析嵌套

JSONObject.parseObject(body, ResponseMenu.class);

例如：解析字符串：

{"code":0,"msg":"","data":[{"module":"接口测试","category_id":"560685e3738a18e0aaf47c1b454ce6b7","category_name":"测试分类","order_no":99,"children":[{"category_id":"560685e3738a18e0aaf47c1b454ce6b7","category_name":"测试分类","order_no":99,"children":[{"category_id":"560685e3738a18e0aaf47c1b454ce6b7","category_name":"测试分类","order_no":99,"children":[]}]},{
"category_id":"560685e3738a18e0aaf47c1b454ce6b7",
"category_name":"测试分类",
"order_no":99,
"children":[]
}]}]}

结构是这样的：
对象的data属性是个数组，数组元素是个对象，
而数组元素的children属性又是个数组，数组元素又是对象，。。。无限

解析结果;

完美解析

 类结构:

import java.util.List;

public class ResponseMenu {


    public int code;

    public String msg;

    public List<Module> data;


    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public List<Module> getData() {
        return data;
    }

    public void setData(List<Module> data) {
        this.data = data;
    }
}

import java.util.List;

public class Module {



    /** 模块名称 */
    private String module;

    /** 分类id */
    private String category_id;

    /** 分类名称 */
    private String category_name;

    /** 排序号 */
    private int order_no;

    /** 子分类 */
    private List<Children> children;


    public String getModule() {
        return module;
    }

    public void setModule(String module) {
        this.module = module;
    }

    public String getCategory_id() {
        return category_id;
    }

    public void setCategory_id(String category_id) {
        this.category_id = category_id;
    }

    public String getCategory_name() {
        return category_name;
    }

    public void setCategory_name(String category_name) {
        this.category_name = category_name;
    }

    public int getOrder_no() {
        return order_no;
    }

    public void setOrder_no(int order_no) {
        this.order_no = order_no;
    }

    public List<Children> getChildren() {
        return children;
    }

    public void setChildren(List<Children> children) {
        this.children = children;
    }
}

import java.util.List;

public class Children {




    /** 分类id */
    private String category_id;

    /** 二级分类名称 */
    private String category_name;

    /** 排序号 */
    private int order_no;

    private List<Children> children;


    public String getCategory_id() {
        return category_id;
    }

    public void setCategory_id(String category_id) {
        this.category_id = category_id;
    }

    public String getCategory_name() {
        return category_name;
    }

    public void setCategory_name(String category_name) {
        this.category_name = category_name;
    }

    public int getOrder_no() {
        return order_no;
    }

    public void setOrder_no(int order_no) {
        this.order_no = order_no;
    }

    public List<Children> getChildren() {
        return children;
    }

    public void setChildren(List<Children> children) {
        this.children = children;
    }
}

https://www.cnblogs.com/zz-1120-wtenlb/p/7414430.html