查看原文:http://www.ibloger.net/article/419.html
最近需要使用树形展示权限,所以研究了一下Java Tree,其实java中有不少Tree展示,具体有如下几种:
Tree的几种开源组件:
1.dtree
2.ztree(国内的,api全中文,我用这个)
3.JTree
4.dhtmlxTree(国外的,种类齐全),网址为:http://dhtmlx.com/docs/products/dhtmlxTree/index.shtml
##以后是我找的还不错的Tree组件,还有很多!
具体使用方式请参考zTreeAPI或zTree Demo
(1)编写数据库脚本添加数据
(2)定义一个基本权限类:Competence.java
public class Competence {
private int id; // 编号
private int pId; // 父节点
private int isParent; // 是否父节点
private String name; // 节点名称
private int open; // 是否打开
// 此处省略 get,set方法
}
(3)创建BaseDao.java联接数据库
package com.demo.test;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
* 连接数据源
* @author 小奎
*/
public class BaseDao {
static Connection conn; // 创建联接
PreparedStatement st; // 预执行类
ResultSet rs; // 结果集
/**
* 得到连接
* @return connnection
*/
public static Connection getConnection() {
try {
// 加载驱动
Class.forName("oracle.jdbc.driver.OracleDriver");
try {
// 创建联接
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl", "scott", "scott");
System.out.println("---------------- 打开连接 -----------------");
} catch (SQLException e) {
System.out.println("---------------- 连接失败 -----------------");
e.printStackTrace();
}
} catch (ClassNotFoundException e) {
System.out.println("---------------- 驱动加载失败 -----------------");
e.printStackTrace();
}
return conn;
}
/**
* 关闭连接对象
* @param rs
* @param st
* @param conn
*/
public static void closeConnection(ResultSet rs, Statement st, Connection conn) {
try {
if (rs != null) {
rs.close();
}
if (st != null) {
st.close();
}
if (conn != null && !conn.isClosed()) {
conn.close();
}
System.out.println("---------------- 关闭连接 -----------------");
} catch (SQLException e) {
System.out.println("---------------- 关闭连接失败 -----------------");
e.printStackTrace();
}
}
}
(4) 创建测试的类 Test.java
package com.demo.test;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
public class Test extends BaseDao {
public List getAllAuthorize() {
List authorizes = new ArrayList();
Connection conn = getConnection(); // 得到联接
try {
st = conn.prepareStatement("select * from authorize2 ");
rs = st.executeQuery(); // 得到结果集
while (rs.next()) {
Competence authorize = new Competence();
authorize.setId(rs.getInt("id"));
authorize.setpId(rs.getInt("pid"));
authorize.setOpen(rs.getInt("open"));
authorize.setIsParent(rs.getInt("isParent"));
authorize.setName(rs.getString("name"));
// 添加到集合
authorizes.add(authorize);
}
} catch (SQLException e) {
System.out.println("---------------- 查询authorize失败 -----------------");
e.printStackTrace();
} finally {
closeConnection(rs, st, conn);
}
return authorizes;
}
/**
* 拼接成json类型
* @return
*/
public String getJSONData(){
Test d = new Test();
List list=d.getAllAuthorize();
StringBuffer json=new StringBuffer("[");
String data="";
for (int i = 0; i < list.size(); i++) {
json.append("{id:"+list.get(i).getId()+",");
json.append("pId:"+list.get(i).getpId()+",");
json.append("name:\""+list.get(i).getName()+"\",");
if (list.get(i).getIsParent() !=0) {
json.append("isParent:"+list.get(i).getIsParent()+",");
}
if (list.get(i).getOpen() !=0) {
json.append("open:"+list.get(i).getOpen()+",");
}
data=json.substring(0,json.lastIndexOf(","))+"},";
json=new StringBuffer(data);
}
data=json.substring(0, json.length()-1)+"]";
System.out.println(data);
return data;
}
public static void main(String[] args) {
Test demoTest=new Test();
demoTest.getJSONData();
}
}
(4) 创建加载zTree 树的html或jsp页面 asyncLoad.html
zTree Demo
(5) 创建一个接收的Servlet,本测试使用jsp代替 loadData.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="com.demo.test.*" %>
<%
String id = request.getParameter("id"); // 父节点编号
System.out.print("得到的节点id:"+id);
Test demo=new Test();
String json=demo.getJSONData();
out.print(json);
%>
注:json数据最终会被拼接成array的形式,如下结果:雷同即可显示
[{id:100,pId:0,name:"父节点",isParent:1,open:1},{id:101,pId:100,name:"叶子节点—1",isParent:1},{id:102,pId:100,name:"叶子节点—2",isParent:1},{id:103,pId:100,name:"叶子节点—3",isParent:1},{id:104,pId:0,name:"NB的父节点",isParent:1,open:1},{id:105,pId:104,name:"叶子节点2—1",isParent:1},{id:106,pId:104,name:"叶子节点2—2",isParent:1},{id:107,pId:104,name:"叶子节点2—3"},{id:108,pId:0,name:"郁闷的父节点",isParent:1},{id:109,pId:108,name:"叶子节点3—1"},{id:110,pId:108,name:"叶子节点3—2"},{id:111,pId:108,name:"叶子节点3—3"},{id:112,pId:101,name:"秘书"},{id:113,pId:101,name:"行政"},{id:114,pId:102,name:"助理"},{id:115,pId:102,name:"保安"},{id:116,pId:103,name:"销售"},{id:117,pId:103,name:"前台"},{id:118,pId:103,name:"主管"},{id:119,pId:105,name:"卫生"},{id:120,pId:106,name:"人事"}]
效果如图
这里的小测试使用了子父节点同时加载完毕效果,加载完毕后,单击父节点不会再次访问数据库,会从缓存中加载。所以这里使用的open属性有效果,如果是单击父节点,加载子节点再次访问数据库的方式,open可能无效。
json的数据中如isParent:1,这样的数据1代表true