java树形菜单对象生成

本文实例为大家分享了java树形菜单对象生成的具体代码，供大家参考，具体内容如下

1、treenode对象

package com.ruoyi.system.utils.vo;

import java.util.arraylist;
import java.util.list;

public class treenode {

  /**
   * 节点id
   */
  private integer id;

  /**
   * 节点名称
   */
  private string name;

  /**
   * 父节点id
   */
  private integer parentid;

  /**
   * 子节点列表
   */
  private list childrenlist = new arraylist();

  public integer getid() {
    return id;
  }

  public void setid(integer id) {
    this.id=id;
  }

  public string getname() {
    return name;
  }

  public void setname(string name) {
    this.name=name;
  }

  public integer getparentid() {
    return parentid;
  }

  public void setparentid(integer parentid) {
    this.parentid=parentid;
  }

  public list getchildrenlist() {
    return childrenlist;
  }

  public void setchildrenlist(list childrenlist) {
    this.childrenlist=childrenlist;
  }
}

2、treeutil

package com.ruoyi.system.utils;

import com.ruoyi.system.utils.vo.treenode;

import java.util.arraylist;
import java.util.list;

public class treeutil {

  private list<treenode> treenodelist =new arraylist<>();

  public treeutil(list<treenode> list){
    treenodelist = list;
  }

  /**
   * 获取节点信息
   * @param nodeid 节点id
   * @return
   */
  public treenode getnodebyid(int nodeid){
    treenode treenode = new treenode();
    for (treenode item : treenodelist) {
      if (item.getid() == nodeid) {
        treenode = item;
        break;
      }
    }
    return treenode;
  }

  /**
   * 获取子节点信息
   * @param nodeid 节点id
   * @return
   */
  public list<treenode> getchildrennodebyid(int nodeid){
    list<treenode> childrentreenode = new arraylist<treenode>();
    for (treenode item : treenodelist) {
      if(item.getparentid() == nodeid){
        childrentreenode.add(item);
      }
    }
    return childrentreenode;
  }

  /**
   * 递归生成tree结构数据
   * @param rootid 根节点id
   * @return
   */
  public treenode generatetreenode(int rootid){
    treenode root = this.getnodebyid(rootid);
    list<treenode> childrentreenode = this.getchildrennodebyid(rootid);
    for (treenode item : childrentreenode) {
      treenode node = this.generatetreenode(item.getid());
      root.getchildrenlist().add(node);
    }
    return root;
  }

  public static void main(string[] args) {
    list<treenode> nodelist = new arraylist<>();
    treenode treenode = new treenode();
    treenode.setid(1);
    treenode.setname("中国");
    treenode.setparentid(0);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(2);
    treenode.setname("北京市");
    treenode.setparentid(1);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(3);
    treenode.setname("浙江省");
    treenode.setparentid(1);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(4);
    treenode.setname("杭州市");
    treenode.setparentid(3);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(5);
    treenode.setname("西湖区");
    treenode.setparentid(4);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(6);
    treenode.setname("滨江区");
    treenode.setparentid(4);
    nodelist.add(treenode);
    treenode = new treenode();
    treenode.setid(7);
    treenode.setname("金华市");
    treenode.setparentid(3);
    nodelist.add(treenode);
    treeutil treeutil = new treeutil(nodelist);
    treenode = treeutil.generatetreenode(1);
    system.out.println("树状结构json格式数据：" + jsonutils.objecttojson(treenode, 1));
  }
}

3、jsonutil

package com.ruoyi.system.utils;

import com.fasterxml.jackson.core.jsonprocessingexception;
import com.fasterxml.jackson.databind.javatype;
import com.fasterxml.jackson.databind.objectmapper;

import java.util.list;

public class jsonutils {

  // 定义jackson对象
  private static final objectmapper mapper = new objectmapper();

  /**
   * 将对象转换成json字符串
   * @param obj 需转换的对象
   * @param  flag json格式化标识（0-否，1-是）
   * @return
   */
  public static <t> string objecttojson(t obj, int flag) {
    if (obj == null) {
      return null;
    }
    try {
      string string;
      if (flag == 1) {
        string = obj instanceof string ? (string) obj : mapper.writerwithdefaultprettyprinter().writevalueasstring(obj);
      } else {
        string = obj instanceof string ? (string) obj : mapper.writevalueasstring(obj);
      }
      return string;
    } catch (jsonprocessingexception e) {
      e.printstacktrace();
    }
    return null;
  }

  /**
   * 将json结果集转化为对象
   *
   * @param jsondata json数据
   * @param beantype 对象中的object类型
   * @return
   */
  public static <t> t jsontopojo(string jsondata, class<t> beantype) {
    try {
      t t = mapper.readvalue(jsondata, beantype);
      return t;
    } catch (exception e) {
      e.printstacktrace();
    }
    return null;
  }

  /**
   * 将json数据转换成pojo对象list
   * <p>title: jsontolist</p>
   * <p>description: </p>
   * @param jsondata
   * @param beantype
   * @return
   */
  public static <t>list<t> jsontolist(string jsondata, class<t> beantype) {
    javatype javatype = mapper.gettypefactory().constructparametrictype(list.class, beantype);
    try {
      list<t> list = mapper.readvalue(jsondata, javatype);
      return list;
    } catch (exception e) {
      e.printstacktrace();
    }

    return null;
  }

  public static void main(string[] args) {
    system.out.println("测试字符串对象：" + objecttojson("hello world", 1));
  }

}

4、运行结果

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。