Tree结构 把json封装成固定的格式

Question

数据库设计:
转化成json之后是这样的
现在想把json封装成固定的格式 看了网上了许多贴子后 出来的效果有点不满意 
请问该如何处理? 麻烦大佬们帮帮忙

Answer 1

我做得一般都是自己拼接的，遍历json，然后根据父id查询，查询出的子就装到children里面,出来差不多是这样的{
    "id": "",
    "name": "",
    "value": "",
    "parentId": "",
    "children": [
        {
            "id": "",
            "name": "",
            "value": "",
            "parentId": "",
            "children": [
                {
                    "id": "",
                    "name": "",
                    "value": "",
                    "parentId": "",
                    "children": [
                        {}
                    ]
                }
            ]
        }
    ]
}

Answer 2

对  就是这个效果,大佬怎么做的,烦请不吝赐教 非常感谢
我写了一个测试方法，你参考下：@Test
    public void test() {
        String str = "[{\"id\": \"1\",\"name\": \"1\",\"value\": \"1\",\"parentid\": \"0\"},{\"id\": \"2\",\"name\": \"2\",\"value\": \"2\",\"parentid\": \"0\"},{\"id\": \"11\",\"name\": \"11\",\"value\": \"11\",\"parentid\": \"1\"},{\"id\": \"111\",\"name\": \"111\",\"value\": \"111\"," +
                "\"parentid\": \"11\"},{\"id\": \"12\",\"name\": \"12\",\"value\": \"12\",\"parentid\": \"1\"},{\"id\": \"22\",\"name\": \"22\",\"value\": \"22\",\"parentid\": \"2\"}]";
        JSONArray jsonArray = JSONObject.parseArray(str);
        //取到第一位
        JSONObject result = new JSONObject(new LinkedHashMap());
        for (int i = 0; i < jsonArray.size(); i++) {
            JSONObject obj = jsonArray.getJSONObject(i);
            if (result.size() == 0 && obj.getString("parentid").equals("0")) {
                result.putAll(obj);
            }
        }
        //遍历下面的子集合
        children(result, result.getString("id"), jsonArray);
        System.out.println(result.toJSONString());
    }    private JSONObject children(JSONObject result, String parentId, JSONArray jsonArray) {
        JSONArray resultArr = new JSONArray();//子集合
        for (int j = 0; j < jsonArray.size(); j++) {
            JSONObject jobj = jsonArray.getJSONObject(j);
            if (parentId.equals(jobj.getString("parentid"))) {
                resultArr.add(jobj);
                children(jobj, jobj.getString("id"), jsonArray);
            }
        }
        result.put("children", resultArr);
        return result;
    }

Answer 3

/**
 * Date: 2019/2/22
 * Time: 11:01
 * 树工具类
 * @author joefan
 * @version 1.0
 */
public class TreeUtil {    /**
     * 组件转化为树形节点并遍历
     *
     * @param list
     */
    public static <T> List<TreeNode> traverseAsync(List<T> list) {
        List<TreeNode> treeNodes = list.stream().map(TreeNode::fromObject).collect(Collectors.toList());
        List<TreeNode> removeList = new ArrayList<>();
        List<TreeNode> returnList = treeNodes.stream()
                .map(root -> traverseAsync(root, treeNodes, removeList))
                .collect(Collectors.toList());
        returnList.removeAll(removeList);
        return returnList;
    }    /**
     * 组件遍历所有树形节点.
     *
     * @param root  根节点
     * @param nodes 所有节点
     * @return 树节点
     */
    private static TreeNode traverseAsync(TreeNode root, List<TreeNode> nodes, List<TreeNode> removeList) {
        List<TreeNode> children = root.getChildren(nodes);
        if (children == null || children.size() == 0) {
            root.setLeaf(true);
        }
        removeList.addAll(children);
        root.setChildren(children);
        children.forEach(child -> traverseAsync(child, nodes, removeList));
        return root;
    }
}
/**
 * 树节点
 * Date: 2019/2/20
 * Time: 14:32
 *
 * @author joefan
 * @version 1.0
 **/
@Data
public class TreeNode {
    private String key;
    private String parent;
    private String title;
    private List<TreeNode> children;
    private boolean isLeaf;
    private Boolean checked;
    private Object extend;//扩展字段    /**
     * 生成树节点
     * @param object 实体对象
     */
    public static TreeNode fromObject(Object object){
        TreeNode treeNode = new TreeNode();
        treeNode.extend = object;
        treeNode.isLeaf = false;
        treeNode.setChecked(false);
        return otherFiled(treeNode, object);
    }    private static TreeNode otherFiled(TreeNode treeNode, Object object) {
        if (object instanceof SysArea) {
            treeNode.key = getValue(object,"id");
            treeNode.title = getValue(object,"areaName");
            treeNode.parent = getValue(object, "parentId");
        }else  {
            treeNode.key = getValue(object,"id");
            treeNode.title = getValue(object,"centerName");
            treeNode.parent = getValue(object, "parentId");
        }
        return treeNode;
    }    /**
     * 获取子节点
     * @description 
     * @param nodes all nodes
     * @return node list
     */
    public List<TreeNode> getChildren(List<TreeNode> nodes) {
        return nodes.stream().filter(node -> Objects.equals(key, node.getParent()))
                .collect(Collectors.toList());
    }}package com.honggv.xueliang.util;import java.lang.reflect.Field;/**
 * 反射工具类
 * @Author: joefan
 * @Date: 2019/2/27 14:40
 */
class ReflectionUtils {    /**
     * 根据反射取值
     * @param object 实体对象
     * @param fieldName 属性名称
     * @return String
     */
    static String getValue(Object object, String fieldName) {
        Field field = org.springframework.util.ReflectionUtils.findField(object.getClass(), fieldName);
        if (field == null)
            return null;
        try {
            field.setAccessible(true);
            return String.valueOf(field.get(object).toString());
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }    /**
     * 根据反射取值
     * @param object 实体对象
     * @param fieldName 属性名称
     * @return Object
     */
    static Object getValueObject(Object object, String fieldName) {
        Field field = org.springframework.util.ReflectionUtils.findField(object.getClass(), fieldName);
        if (field == null)
            return null;
        try {
            field.setAccessible(true);
            return field.get(object);
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }    /**
     * 根据反射取值
     * @param object 实体对象
     * @param fieldName 属性名称
     * @return Boolean
     */
    static Boolean getValueBoolean(Object object, String fieldName) {
        Field field = org.springframework.util.ReflectionUtils.findField(object.getClass(), fieldName);
        if (field == null)
            return null;
        try {
            field.setAccessible(true);
            return field.get(object) != null && Boolean.valueOf(field.get(object).toString());
        } catch (IllegalAccessException e) {
            throw new RuntimeException(e);
        }
    }
}