jstreejava_javajsTree通用的树生成代码

public class Tools{

public static void main(String[] args) {//测试用例

TreeNodes keys &＃61; new TreeNodes ("ptId", "parentId", "ptName", "ptLevels");

//String str &＃61; "[{\"parentId\":\"0\",\"ptDeleted\":\"0\",\"ptId\":\"1\",\"ptLevels\":1,\"ptName\":\"类型1\"},{\"parentId\":\"0\",\"ptDeleted\":\"0\",\"ptId\":\"2\",\"ptLevels\":1,\"ptName\":\"类型2\"},{\"parentId\":\"2\",\"ptDeleted\":\"0\",\"ptId\":\"3\",\"ptLevels\":2,\"ptName\":\"类型23\"}]";

//String s1 &＃61; changeKey(str, keys);

//System.out.println(s1);

List> pts &＃61; getListMap();//模拟获取列表信息

List list &＃61; Tools.formatTree(pts,keys);//将列表转换为树

System.out.println(JSON.toJSONString(list));

}

public static List> getListMap(){

List> list &＃61; new ArrayList>();

Map map1 &＃61; new HashMap();

map1.put("ptId",1); map1.put("parentId",0); map1.put("ptLevels",1);map1.put("ptName","测试用例1");list.add(map1);

Map map2 &＃61; new HashMap();

map2.put("ptId",2); map2.put("parentId",0); map2.put("ptLevels",1);map2.put("ptName","测试用例2");list.add(map2);

Map map3 &＃61; new HashMap();

map3.put("ptId",3); map3.put("parentId",0); map3.put("ptLevels",1);map3.put("ptName","测试用例3");list.add(map3);

Map map4 &＃61; new HashMap();

map4.put("ptId",4); map4.put("parentId",1); map4.put("ptLevels",2);map4.put("ptName","测试用例4");list.add(map4);

Map map5 &＃61; new HashMap();

map5.put("ptId",5); map5.put("parentId",2); map5.put("ptLevels",2);map5.put("ptName","测试用例5");list.add(map5);

Map map6 &＃61; new HashMap();

map6.put("ptId",6); map6.put("parentId",3); map6.put("ptLevels",2);map6.put("ptName","测试用例6");list.add(map6);

Map map7 &＃61; new HashMap();

map7.put("ptId",7); map7.put("parentId",4); map7.put("ptLevels",3);map7.put("ptName","测试用例7");list.add(map7);

Map map8 &＃61; new HashMap();

map8.put("ptId",8); map8.put("parentId",5); map8.put("ptLevels",3);map8.put("ptName","测试用例8");list.add(map8);

return list;

}

/** * &＃64;param list 树的内容&＃xff0c;需要按照level从小到大进行排序&＃xff0c;否则无法获取到第一个层级&＃xff0c;且易造成树的分支丢失 * &＃64;param keys * &＃64;param * &＃64;return */

public static List formatTree(List list, TreeNodes keys) {

if (list &＃61;&＃61; null || list.size() <&＃61; 0) {

return new ArrayList<>();

}

String jsonStr &＃61; JSON.toJSONString(list);

jsonStr &＃61; changeKey(jsonStr, keys);//change&＃xff0c;不改变格式&＃xff0c;不需要这段代码&＃xff0c;直接删除

List treeNodes &＃61; listClone(jsonStr, TreeNodes.class);//change&＃xff0c;不改变格式&＃xff0c;不需要这段代码&＃xff0c;直接删除

Map> map &＃61; new HashMap<>();//change&＃xff0c;修改List为指定的类型

//转换字段

List root &＃61; null;//根目录 //change&＃xff0c;修改List为指定的类型

for (TreeNodes current : treeNodes) {//change&＃xff0c;修改List为指定的类型

{//添加当前元素到指定级别

String level &＃61; current.getLevel();//change&＃xff0c;修改获取层级的方法

if (!map.containsKey(level)) {//不存在&＃xff0c;先添加list

map.put(level, new ArrayList());//change&＃xff0c;修改List为指定的类型

}

List arr &＃61; map.get(level);//当前层级//change&＃xff0c;修改List为指定的类型

arr.add(current);

if (root &＃61;&＃61; null) {//表示是第一级

root &＃61; arr;

}

}

//将当前元素添加到父级的子元素列表里

{

List parentTree &＃61; map.get(String.valueOf(Integer.valueOf(current.getLevel()) - 1));//change&＃xff0c;修改List、获取层级的方法

if (parentTree &＃61;&＃61; null) {

continue;

}

for (TreeNodes parent : parentTree) {//change&＃xff0c;修改List为指定的类型

if (parent.getId().equals(current.getpId())) {//如果找不到父级&＃xff0c;则为异常数据&＃xff0c;抛弃 //change&＃xff0c;修改上下级关联的判断依据

parent.getChildren().add(current);

break;

}

}

}

}

return root;

}

/** * 更新字段 */

public static String changeKey(String json, TreeNodes keys) {

if (StringUtils.isEmpty(json) || keys &＃61;&＃61; null) {

return "";

}

json &＃61; json.replaceAll(keys.getId(), "id")

.replaceAll(keys.getText(), "text")

.replaceAll(keys.getpId(), "pId")

.replaceAll(keys.getLevel(), "level");

return json;

}

/** * 将一个对象的列表转换为另一个对象的列表 * * &＃64;param k * &＃64;param clazz * &＃64;param * &＃64;param * &＃64;return */

public static List listClone(List k, Class clazz) {

List list &＃61; JSONArray.parseArray((JSONArray.toJSON(k)).toString(), clazz);

return list;

}

/** * 将json格式的字符串转换为指定对象的列表 * * &＃64;param str * &＃64;param clazz * &＃64;param * &＃64;return */

public static List listClone(String str,Class clazz){

List list &＃61; JSONArray.parseArray(str, clazz);

return list;

}

}