Java实现树形结构的数据转Json格式
在项目中难免会用到树形结构，毕竟这是一种常用的组织架构。楼主这里整理了两个实现的版本，可以直接拿来使用，非常方便。
楼主没有单独建项目，直接在以前的一个Demo上实现的。第一种，看下面代码：
package com.johanChan.WebSocket.utils; import com.alibaba.fastjson.JSON; import java.util.ArrayList;
import java.util.List; //图层结构
public class TreeBuilder { List<Node> nodes = new ArrayList<>(); public String buildTree(List<Node> nodes) {
TreeBuilder treeBuilder = new TreeBuilder(nodes);
return treeBuilder.buildJSONTree();
} public TreeBuilder() {} public TreeBuilder(List<Node> nodes) {
super();
this.nodes = nodes;
} // 构建JSON树形结构
public String buildJSONTree() {
List<Node> nodeTree = buildTree();
String jsonStr = JSON.toJSONString(nodeTree);
return jsonStr;
} // 构建树形结构
public List<Node> buildTree() {
List<Node> treeNodes = new ArrayList<>();
List<Node> rootNodes = getRootNodes();
for (Node rootNode : rootNodes) {
buildChildNodes(rootNode);
treeNodes.add(rootNode);
}
return treeNodes;
} // 递归子节点
public void buildChildNodes(Node node) {
List<Node> children = getChildNodes(node);
if (!children.isEmpty()) {
for (Node child : children) {
buildChildNodes(child);
}
node.setChildren(children);
}
} // 获取父节点下所有的子节点
public List<Node> getChildNodes(Node pnode) {
List<Node> childNodes = new ArrayList<>();
for (Node n : nodes) {
if (pnode.getId().equals(n.getParentId())) {
childNodes.add(n);
}
}
return childNodes;
} // 判断是否为根节点
public boolean rootNode(Node node) {
boolean isRootNode = true;
for (Node n : nodes) {
if (node.getParentId().equals(n.getId())) {
isRootNode = false;
break;
}
}
return isRootNode;
} // 获取集合中所有的根节点
public List<Node> getRootNodes() {
List<Node> rootNodes = new ArrayList<>();
for (Node n : nodes) {
if (rootNode(n)) {
rootNodes.add(n);
}
}
return rootNodes;
} public static class Node {
private Integer id;
private Integer parentId;
private String name;
private String code;
private Integer level;
private List<Node> children; public Node() {}
public Node(Integer id,Integer parentId,String name,String code,Integer level){
super();
this.id = id;
this.parentId = parentId;
this.name = name;
this.code = code;
this.level = level;
} public Integer getId() {
return id;
} public void setId(Integer id) {
this.id = id;
} public Integer getParentId() {
return parentId;
} public void setParentId(Integer parentId) {
this.parentId = parentId;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getCode() {
return code;
} public void setCode(String code) {
this.code = code;
} public Integer getLevel() {
return level;
} public void setLevel(Integer level) {
this.level = level;
} public List<Node> getChildren() {
return children;
} public void setChildren(List<Node> children) {
this.children = children;
}
}
}
看起来很长对吗？没关系，直接copy一下就可以使用。首先生成一个树形结构的数据：
public static List<TreeBuilder.Node> buildNode(){
List<TreeBuilder.Node> nodeList = new ArrayList<>();
TreeBuilder.Node node = new TreeBuilder.Node(0,-1,"地球","WORD",1);
TreeBuilder.Node node1 = new TreeBuilder.Node(1,0,"中国","CHN",1);
TreeBuilder.Node node2 = new TreeBuilder.Node(2,1,"华北区域","A",2);
TreeBuilder.Node node3 = new TreeBuilder.Node(3,1,"华南区域","B",2);
TreeBuilder.Node node4 = new TreeBuilder.Node(4,1,"华东区域","C",2);
TreeBuilder.Node node5 = new TreeBuilder.Node(5,1,"华西区域","D",2);
TreeBuilder.Node node6 = new TreeBuilder.Node(6,1,"华中区域","E",2);
TreeBuilder.Node node7 = new TreeBuilder.Node(7,6,"河南","豫",3);
TreeBuilder.Node node8 = new TreeBuilder.Node(8,6,"湖北","鄂",3);
TreeBuilder.Node node9 = new TreeBuilder.Node(9,6,"湖南","湘",3);
TreeBuilder.Node node10 = new TreeBuilder.Node(10,6,"江西","赣",3);
TreeBuilder.Node node11 = new TreeBuilder.Node(11,7,"郑州","豫A",4);
TreeBuilder.Node node12 = new TreeBuilder.Node(12,7,"开封","豫B",4);
TreeBuilder.Node node13 = new TreeBuilder.Node(13,7,"洛阳","豫C",4);
TreeBuilder.Node node14 = new TreeBuilder.Node(14,7,"南阳","豫R",4);
TreeBuilder.Node node15 = new TreeBuilder.Node(15,11,"金水区","豫A-1",5);
nodeList.add(node);
nodeList.add(node1);nodeList.add(node2);nodeList.add(node3);
nodeList.add(node4);nodeList.add(node5);nodeList.add(node6);
nodeList.add(node7);nodeList.add(node8);nodeList.add(node9);
nodeList.add(node10);nodeList.add(node11);nodeList.add(node12);
nodeList.add(node13);nodeList.add(node14);nodeList.add(node15);
return nodeList;
}
然后调用new TreeBuilder().buildTree(nodeList)就可以返回json格式的字符串了：
package com.johanChan.WebSocket.controller; import com.alibaba.fastjson.JSON;
import com.johanChan.WebSocket.utils.CommonUtils;
import com.johanChan.WebSocket.utils.TreeBuilder;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody; import java.util.List; @Controller
public class TreeController { List<TreeBuilder.Node> nodeList ;
{
nodeList = CommonUtils.buildNode();
} @ResponseBody
@RequestMapping("/getTreeJson")
public String getTreeJson() {
// List<TreeBuilder.Node> nodeList = CommonUtils.buildNode();
String result = CommonUtils.buildTree(nodeList);
return result;
} }
启动项目，访问/getTreeJson可以看到，页面返回了json字符串：
整理后如下：
[
{
"children":[
{
"children":[
{
"code":"A",
"id":2,
"level":2,
"name":"华北区域",
"parentId":1
},
{
"code":"B",
"id":3,
"level":2,
"name":"华南区域",
"parentId":1
},
{
"code":"C",
"id":4,
"level":2,
"name":"华东区域",
"parentId":1
},
{
"code":"D",
"id":5,
"level":2,
"name":"华西区域",
"parentId":1
},
{
"children":[
{
"children":[
{
"children":[
{
"code":"豫A-1",
"id":15,
"level":5,
"name":"金水区",
"parentId":11
}
],
"code":"豫A",
"id":11,
"level":4,
"name":"郑州",
"parentId":7
},
{
"code":"豫B",
"id":12,
"level":4,
"name":"开封",
"parentId":7
},
{
"code":"豫C",
"id":13,
"level":4,
"name":"洛阳",
"parentId":7
},
{
"code":"豫R",
"id":14,
"level":4,
"name":"南阳",
"parentId":7
}
],
"code":"豫",
"id":7,
"level":3,
"name":"河南",
"parentId":6
},
{
"code":"鄂",
"id":8,
"level":3,
"name":"湖北",
"parentId":6
},
{
"code":"湘",
"id":9,
"level":3,
"name":"湖南",
"parentId":6
},
{
"code":"赣",
"id":10,
"level":3,
"name":"江西",
"parentId":6
}
],
"code":"E",
"id":6,
"level":2,
"name":"华中区域",
"parentId":1
}
],
"code":"CHN",
"id":1,
"level":1,
"name":"中国",
"parentId":0
}
],
"code":"WORD",
"id":0,
"level":1,
"name":"地球",
"parentId":-1
}
]
第一种方法完成，下面是第二种实现，首先建立一个类：
package com.johanChan.WebSocket.utils; import java.util.ArrayList;
import java.util.List; public class Tree<T> {
/**
* 节点ID
*/
private Integer id;
/**
* 显示节点文本
*/
private String text;
/**
* 父ID
*/
private Integer parentId; private Integer level;
/**
* 节点的子节点
*/
// private List<Tree<T>> nodes = new ArrayList<Tree<T>>();
private List<Tree<T>> nodes = null; public Tree() {}
public Tree(Integer id,Integer parentId,String text,Integer level){
super();
this.id = id;
this.text = text;
this.parentId = parentId;
this.level = level;
} public Integer getId() {
return id;
} public void setId(Integer id) {
this.id = id;
} public String getText() {
return text;
} public void setText(String text) {
this.text = text;
} public Integer getParentId() {
return parentId;
} public void setParentId(Integer parentId) {
this.parentId = parentId;
} public Integer getLevel() {
return level;
} public void setLevel(Integer level) {
this.level = level;
} public List<Tree<T>> getNodes() {
if(nodes==null){
nodes = new ArrayList<Tree<T>>();
}
return nodes;
} public void setNodes(List<Tree<T>> nodes) {
this.nodes = nodes;
} }
然后对Tree进行排序：
package com.johanChan.WebSocket.utils; import java.util.ArrayList;
import java.util.List; public class BuildTree {
public static <T> List<Tree<T>> build(List<Tree<T>> nodes) {
if (nodes == null) {
return null;
}
List<Tree<T>> topNodes = new ArrayList<>(); for (Tree<T> children : nodes) {
String pid = children.getParentId();
if (pid.equals(children.getId() )) {
topNodes.add(children);
continue;
}
for (Tree<T> parent : nodes) {
String id = parent.getId();
if (id != null && id.equals(pid)) {
parent.getNodes().add(children);
}
}
}
return topNodes;
} }
然后生成数据：
public static List<Tree<TreeBuilder.Node>> buildTree(){
List<Tree<TreeBuilder.Node>> treeList = new ArrayList<>();
Tree<TreeBuilder.Node> tree = new Tree<TreeBuilder.Node>(0,0,"地球",1);
Tree tree1 = new Tree(1,0,"中国",1);
Tree tree2 = new Tree(2,1,"华北区域",2);
Tree tree3 = new Tree(3,1,"华南区域",2);
Tree tree4 = new Tree(4,1,"华东区域",2);
Tree tree5 = new Tree(5,1,"华西区域",2);
Tree tree6 = new Tree(6,1,"华中区域",2);
Tree tree7 = new Tree(7,6,"河南",3);
Tree tree8 = new Tree(8,6,"湖北",3);
Tree tree9 = new Tree(9,6,"湖南",3);
Tree tree10 = new Tree(10,6,"江西",3);
Tree tree11 = new Tree(11,7,"郑州",4);
Tree tree12 = new Tree(12,7,"开封",4);
Tree tree13 = new Tree(13,7,"洛阳",4);
Tree tree14 = new Tree(14,7,"南阳",4);
Tree tree15 = new Tree(15,11,"金水区",5);
treeList.add(tree);
treeList.add(tree1);treeList.add(tree2);treeList.add(tree3);
treeList.add(tree4);treeList.add(tree5);treeList.add(tree6);
treeList.add(tree7);treeList.add(tree8);treeList.add(tree9);
treeList.add(tree10);treeList.add(tree11);treeList.add(tree12);
treeList.add(tree13);treeList.add(tree14);treeList.add(tree15);
return treeList;
}
调用方法：
package com.johanChan.WebSocket.controller; import com.alibaba.fastjson.JSON;
import com.johanChan.WebSocket.utils.BuildTree;
import com.johanChan.WebSocket.utils.CommonUtils;
import com.johanChan.WebSocket.utils.Tree;
import com.johanChan.WebSocket.utils.TreeBuilder;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody; import java.util.List; @Controller
public class TreeController { List<TreeBuilder.Node> nodeList ;
List<Tree<TreeBuilder.Node>> treeList;
{
nodeList = CommonUtils.buildNode();
treeList = CommonUtils.buildTree();
} @ResponseBody
@RequestMapping("/getTreeJson")
public String getTreeJson() {
// List<TreeBuilder.Node> nodeList = CommonUtils.buildNode();
// String result = CommonUtils.buildTree(nodeList);
List<Tree<TreeBuilder.Node>> resultList = BuildTree.build(treeList);
String result = JSON.toJSONString(resultList);
return result;
} }
返回数据如下：
整理后：
[
{
"id":0,
"level":1,
"nodes":[
{
"id":1,
"level":1,
"nodes":[
{
"id":2,
"level":2,
"nodes":[ ],
"parentId":1,
"text":"华北区域"
},
{
"id":3,
"level":2,
"nodes":[ ],
"parentId":1,
"text":"华南区域"
},
{
"id":4,
"level":2,
"nodes":[ ],
"parentId":1,
"text":"华东区域"
},
{
"id":5,
"level":2,
"nodes":[ ],
"parentId":1,
"text":"华西区域"
},
{
"id":6,
"level":2,
"nodes":[
{
"id":7,
"level":3,
"nodes":[
{
"id":11,
"level":4,
"nodes":[
{
"id":15,
"level":5,
"nodes":[ ],
"parentId":11,
"text":"金水区"
}
],
"parentId":7,
"text":"郑州"
},
{
"id":12,
"level":4,
"nodes":[ ],
"parentId":7,
"text":"开封"
},
{
"id":13,
"level":4,
"nodes":[ ],
"parentId":7,
"text":"洛阳"
},
{
"id":14,
"level":4,
"nodes":[ ],
"parentId":7,
"text":"南阳"
}
],
"parentId":6,
"text":"河南"
},
{
"id":8,
"level":3,
"nodes":[ ],
"parentId":6,
"text":"湖北"
},
{
"id":9,
"level":3,
"nodes":[ ],
"parentId":6,
"text":"湖南"
},
{
"id":10,
"level":3,
"nodes":[ ],
"parentId":6,
"text":"江西"
}
],
"parentId":1,
"text":"华中区域"
}
],
"parentId":0,
"text":"中国"
}
],
"parentId":0,
"text":"地球"
}
]
OK！以上两种方法都比较有通用性，把自己的数据整理后调用就可以了。
Java实现树形结构的数据转Json格式的更多相关文章
- java返回树形结构的正确姿势
业务场景 通常我们前端需要一个树形的导航菜单或者分类菜单,如后台权限管理中的权限树,亦或者下面例子中商城系统的商品分类多级菜单(一般为三级菜单) 数据库设计 数据库设计,采用parentId来指向自己 ...
- C# 把带有父子关系的数据转化为------树形结构的数据 ，以及 找出父子级关系的数据中里面的根数据Id
紧接上一篇,将List<Menu>的扁平结构数据, 转换成树形结构的数据 返回给前端 , 废话不多说,开撸! --------------------- 步骤: 1. 建 Menu ...
- 数据转换为json格式的方法
数据转换为json格式: 如果一张表中存在主外键关系,模板自动生成的类是不可以转换成JSON格式的,此时需要重新写一个类,类前面需加[DataContract],字段前需加[DataMember],实 ...
- jmeter随笔（1）-在csv中数据为json格式的数据不完整
昨天同事在使用jmeter遇到问题,在csv中数据为json格式的数据,在jmeter中无法完整的取值,小怪我看了下,给出解决办法,其实很简单,我们一起看看,看完了记得分享给你的朋友. 问题现象: 1 ...
- C# 任意类型数据转JSON格式（转）
HOT SUMMER 每天都是不一样,积极的去感受生活 C# 任意类型数据转JSON格式 /// <summary> /// List转成json /// </summary> ...
- 关于多条数据转为json格式单次传输的问题 2017.05.27
数据形式如下: var mycars = [];//定义数组存放多条数据 for(var i=0;i<2;i++){ var jsonData = {};//定义变量存放单条数据 jsonDat ...
- 了解php数据转json格式与前端交互基础
php数据转json格式与前端交互 ArryJson1.php <?php $test=array(); $word=array("我12","要43", ...
- 接口数据转json格式
接口数据转json格式 function tojson($result, $callback = null){ header('Content-Type:text/html; charset=utf- ...
- jmeter 导入csv数据中json格式数据取值不完整
1.jmeter中添加csv数据文件时,数据是json格式 2.jmeter中执行取值发现只取了一部分 分析原因,json格式数据,中间有逗号,而csv是根据逗号来分割的,这回导致我们取值错位. 解决 ...
随机推荐
- ngx lua获取时间戳的几种方式
原创自由de单车 最后发布于2017-02-14 14:58:43 阅读数 18218 收藏 在ngx_lua里,获取时间相关信息的方式大概有4种(见下面代码): print(string.forma ...
- pandas之groupby分组与pivot_table透视
一.groupby 类似excel的数据透视表,一般是按照行进行分组,使用方法如下. df.groupby(by=None, axis=0, level=None, as_index=True, so ...
- 【Laravel 】faker数据填充详解
安装 在laravel中已经自动集成,无需手动安装.如需在其他地方使用,可使用以下命令进行安装. composer require fzaninotto/faker 为Faker指定中文支持 可通过在 ...
- Oracle数据库出现[23000][2291] ORA-02291: integrity constraint (SIMTH.SYS_C005306) violated异常
参考链接 这个异常发生在往中间表中插入数据时,这时出现异常是因为关联的某个表没有插入数据,所以给没有插入数据的关联表插入数据,再给中间表插入数据此时异常就会解决.
- PHP strcoll() 函数
实例 比较字符串: <?php高佣联盟 www.cgewang.comsetlocale (LC_COLLATE, 'NL');echo strcoll("Hello World!&q ...
- PDOStatement::getAttribute
PDOStatement::getAttribute — 检索一个语句属性(PHP 5 >= 5.1.0, PECL pdo >= 0.2.0)高佣联盟 www.cgewang.com 说 ...
- 执行HiveSQL出现的问题
-- ::, INFO [main] org.apache.hadoop.hive.ql.exec.ReduceSinkOperator: RECORDS_OUT_INTERMEDIATE:, -- ...
- HTML学习笔记（一）——基础标签及常用编辑器技巧
HTML 初识html 什么是html? html是超文本标记语言(hyper text markup language) html5的基本结构 <!DOCTYPE html> <! ...
- 小伙子自从学会用Python爬取岛国“动作”电影，身体一天不如一天
在互联网的世界里,正确的使用VPN看看外面的世界,多了解了解世界的发展.肉身翻墙后,感受一下外面的肮脏世界.墙内的朋友叫苦不迭,由于某些原因,VPN能用的越来越少.上周我的好朋友狗子和我哭诉说自己常用 ...
- “随手记”开发记录day10
今天完成了各个demo合并,并进行测试,中间出现了一些bug, 例如再点击主页面预留的菜单按钮时会出现闪退 在手机上运行更新页面时会直接崩溃 还有发现的问题有,不能查看往期的记录