1、json数据（目标）
[{
label: '一级 1',
children: [{
label: '二级 1-1',
children: [{
label: '三级 1-1-1'
}]
}]
}, {
label: '一级 2',
children: [{
label: '二级 2-1',
children: [{
label: '三级 2-1-1'
}]
}, {
label: '二级 2-2',
children: [{
label: '三级 2-2-1'
}]
}]
}, {
label: '一级 3',
children: [{
label: '二级 3-1',
children: [{
label: '三级 3-1-1'
}]
}, {
label: '二级 3-2',
children: [{
label: '三级 3-2-1'
}]
}]
}]
View Code
2、基础类型
package test;
import java.util.List;
/**
* chao
*/
public class DataItem {
private String label;
private List<DataItem> children;
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
public List<DataItem> getChildren() {
return children;
}
public void setChildren(List<DataItem> children) {
this.children = children;
}
}
View Code
package test;
/**
* 代表数据库里的表
*/
public class DataModel {
private Integer id;
private String label;
private Integer pId;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
public Integer getPId() {
return pId;
}
public void setPId(Integer pId) {
this.pId = pId;
}
public DataModel(Integer id, String label, Integer pId) {
this.id = id;
this.label = label;
this.pId = pId;
}
}
View Code
3、手动拼接树形结构
// 手动拼接json格式
{
List<DataItem> list = new ArrayList<DataItem>();
//第一条数据
{
DataItem data = new DataItem();
data.setLabel("一级 1");
List<DataItem> data_child = new ArrayList<DataItem>();
data.setChildren(data_child);
DataItem data_child_Data1 = new DataItem();
data_child_Data1.setLabel("二级 1-1");
List<DataItem> data_child_Data1_child = new ArrayList<DataItem>();
data_child_Data1.setChildren(data_child_Data1_child);
data_child.add(data_child_Data1);
DataItem child1Data1_child_Data1 = new DataItem();
child1Data1_child_Data1.setLabel("三级 1-1-1");
data_child_Data1_child.add(child1Data1_child_Data1);
list.add(data);
}
//第二条数据
{
DataItem data = new DataItem();
data.setLabel("一级 2");
List<DataItem> data_child = new ArrayList<DataItem>();
data.setChildren(data_child);
//第一条
{
DataItem data_child_Data1 = new DataItem();
data_child_Data1.setLabel("二级 2-1");
List<DataItem> data_child_Data1_child = new ArrayList<DataItem>();
data_child_Data1.setChildren(data_child_Data1_child);
data_child.add(data_child_Data1);
DataItem child1Data1_child_Data1 = new DataItem();
child1Data1_child_Data1.setLabel("三级 2-1-1");
data_child_Data1_child.add(child1Data1_child_Data1);
}
//第二条
{
DataItem data_child_Data1 = new DataItem();
data_child_Data1.setLabel("二级 2-2");
List<DataItem> data_child_Data1_child = new ArrayList<DataItem>();
data_child_Data1.setChildren(data_child_Data1_child);
data_child.add(data_child_Data1);
DataItem child1Data1_child_Data1 = new DataItem();
child1Data1_child_Data1.setLabel("三级 2-2-1");
data_child_Data1_child.add(child1Data1_child_Data1);
}
list.add(data);
}
//第三条数据
{
DataItem data = new DataItem();
data.setLabel("一级 3");
List<DataItem> data_child = new ArrayList<DataItem>();
data.setChildren(data_child);
//第一条
{
DataItem data_child_Data1 = new DataItem();
data_child_Data1.setLabel("二级 3-1");
List<DataItem> data_child_Data1_child = new ArrayList<DataItem>();
data_child_Data1.setChildren(data_child_Data1_child);
data_child.add(data_child_Data1);
DataItem child1Data1_child_Data1 = new DataItem();
child1Data1_child_Data1.setLabel("三级 3-1-1");
data_child_Data1_child.add(child1Data1_child_Data1);
}
//第二条
{
DataItem data_child_Data1 = new DataItem();
data_child_Data1.setLabel("二级 3-2");
List<DataItem> data_child_Data1_child = new ArrayList<DataItem>();
data_child_Data1.setChildren(data_child_Data1_child);
data_child.add(data_child_Data1);
DataItem child1Data1_child_Data1 = new DataItem();
child1Data1_child_Data1.setLabel("三级 3-2-1");
data_child_Data1_child.add(child1Data1_child_Data1);
}
list.add(data);
}
System.out.println("----------手动拼接----------");
System.out.println(JSON.toJSONString(list));
View Code
4、递归拼接
//原始数据
List<DataModel> dataList = new ArrayList();
{
dataList.add(new DataModel(1, "一级 1", 0));
dataList.add(new DataModel(2, "二级 1-1", 1));
dataList.add(new DataModel(3, "三级 1-1-1", 2));
dataList.add(new DataModel(4, "一级 2", 0));
dataList.add(new DataModel(5, "二级 2-1", 4));
dataList.add(new DataModel(6, "三级 2-1-1", 5));
dataList.add(new DataModel(7, "二级 2-2", 4));
dataList.add(new DataModel(8, "三级 2-2-1", 7));
dataList.add(new DataModel(9, "一级 3", 0));
dataList.add(new DataModel(10, "二级 3-1", 9));
dataList.add(new DataModel(11, "三级 3-1-1", 10));
dataList.add(new DataModel(12, "二级 3-2", 9));
dataList.add(new DataModel(13, "三级 3-2-1", 12));
}
//树结构结果
List<DataItem> treeList = new ArrayList<DataItem>();
treeList = GetTreeData(dataList, 0);
System.out.println("----------递归拼接----------");
System.out.println(JSON.toJSONString(treeList));
/**
* 递归
*
* @param sourceDataList
* @param pId
* @return
*/
private static List<DataItem> GetTreeData(List<DataModel> sourceDataList, Integer pId) {
List<DataItem> returnList = new ArrayList<DataItem>();
for (Integer i = 0; i < sourceDataList.size(); i++) {
DataModel itemData = sourceDataList.get(i);
if (itemData.getPId().equals(pId)) {
DataItem item = new DataItem();
item.setLabel(itemData.getLabel());
List children = GetTreeData(sourceDataList, itemData.getId());
if (children.size() > 0)
item.setChildren(children);
returnList.add(item);
}
}
return returnList;
}
标签：java,DataItem,Data1,树形,add,拼接,child,new,data From： https://www.cnblogs.com/mulans/p/17417572.html