extjs3 tree 从数据库创建设计、处理到前台展示

 在网上看到很多关于extjs树的文章，他们说的都是如何还回json格式，但是并没有涉及到后台数据库表的结构，本文简单介绍下从表的设计到前台的展示。

sql：

create table tree(

   id int primary key,

   parent_id int not null,

   code varchar(50)

)

 

insert into tree values(1,0,'根节点');

insert into tree values(2,1,'一级菜单');

insert into tree values(3,1,'一级菜单');

insert into tree values(4,2,'二级菜单');

insert into tree values(5,2,'二级菜单');

insert into tree values(6,3,'二级菜单');

insert into tree values(7,4,'三级菜单');

insert into tree values(8,4,'三级菜单');

 

 

读取数据库表信息

 

 package dao;

 

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.List;

 

import com.wang.util.Menu;

 

public class AllBook {

 

public static final String URL = "jdbc:sqlserver://localhost:14333;DatabaseName=gm";

public static final String serName = "sa";

public static final String Pwd = "jinbingchuan";

 

public List<Tree> fillbook() {

List<Tree> bookList = new ArrayList<Tree>();

Connection con = null;

Statement st = null;

ResultSet rs = null;

try {

   con = getConnection();

   st = con.createStatement();

String sql = "select * from tree order by id desc"; // 查询数据SQL语句s

   rs = st.executeQuery(sql); // 获取结果集

while (rs.next()) {

Tree tree = new Tree();

tree.setId(rs.getInt("id"));

tree.setCode(rs.getString("Code"));

tree.setParentId(rs.getInt("parent_id"));

bookList.add(tree);

}

 

} catch (Exception ex) {

ex.printStackTrace(); // 输出出错信息

}

finally{

try {

rs.close();

st.close();

con.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} // 关闭连接

}

return bookList;

}

 

public static Connection getConnection() {

Connection conn = null;

try {

Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

conn = DriverManager.getConnection(URL, serName, Pwd); // 得到连接

} catch (ClassNotFoundException e) {

e.printStackTrace();

} catch (SQLException e) {

e.printStackTrace();

}

 

return conn;

}

 

public void recurison(List<Tree> books,Menu menu){

if(hasChildren(books,menu)){

menu.setLeaf(false);

menu.setId(menu.getId());

menu.setText(menu.getText());

List<Menu> children = getChildren(books,menu);

menu.setChildren(children);

for(Menu n:children){

recurison(books,n);

}

}

else{

menu.setLeaf(true);

menu.setId(menu.getId());

menu.setText(menu.getText());

}

}

 

public Menu getRoot(List<Tree> books){

for(Tree b:books){

if(b.getParentId().intValue() == 0){

Menu menu = new Menu();

menu.setId(b.getId());

menu.setText(b.getCode());

return menu;

}

}

return null;

}

 

public boolean hasChildren(List<Tree> books,Menu menu){

for(Tree b:books){

if(b.getParentId().intValue() == menu.getId().intValue())

return true;

}

return false;

}

 

public List<Menu> getChildren(List<Tree> books,Menu menus){

List<Menu> bookList = new ArrayList<Menu>();

for(Tree b:books){

if(b.getParentId().intValue() == menus.getId().intValue()){

Menu menu = new Menu();

menu.setId(b.getId());

menu.setText(b.getCode());

bookList.add(menu);

}

}

return bookList;

}

 

public Menu getAllBooks() {

List<Tree> books = fillbook();

Menu menu = getRoot(books);

recurison(books,menu);

return menu;

}

 

}

 

 

 tree.java如下：

 

          package dao;

 

public class Tree {

private Integer id;

private Integer parentId;

private String Code;

 

 

 

public Tree() {

super();

// TODO Auto-generated constructor stub

}

 

public Tree(Integer id, Integer parentId, String code) {

super();

this.id = id;

this.parentId = parentId;

Code = code;

}

 

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 getCode() {

return Code;

}

 

public void setCode(String code) {

Code = code;

}

 

 

@Override

public String toString() {

return "Book [BookName=" 

+ ", Code=" + Code + ", id=" + id + ", parentId=" + parentId

+ "]";

}

 

}

 

 

Menu.java:

 

 

import java.util.List;

 

public class Menu {

 

 

private String text;

 

private Integer id;

 

private String cls;

 

private boolean leaf;

 

private String href;

 

 

private List<Menu> children;

 

private String hrefTarget;

 

public String getHrefTarget() {

return hrefTarget;

}

 

public void setHrefTarget(String hrefTarget) {

this.hrefTarget = hrefTarget;

}

 

public String getText() {

return text;

}

 

public void setText(String text) {

this.text = text;

}

 

public Integer getId() {

return id;

}

 

public void setId(Integer string) {

this.id = string;

}

 

public String getCls() {

return cls;

}

 

public void setCls(String cls) {

this.cls = cls;

}

 

public boolean isLeaf() {

return leaf;

}

 

public void setLeaf(boolean string) {

this.leaf = string;

}

 

public List<Menu> getChildren() {

return children;

}

 

public void setChildren(List<Menu> children) {

this.children = children;

}

 

public String getHref() {

return href;

}

 

public void setHref(String href) {

this.href = href;

}

 

 

}

 

 

 

servlet:

 

package com.wang.servlet.ext;

 

import java.io.IOException;

import java.io.PrintWriter;

 

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

 

import net.sf.json.JSONArray;

 

import com.wang.util.Menu;

 

import dao.AllBook;

 

public class BookServlet extends HttpServlet {

 

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

 

this.doPost(request, response);

}

 

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

               String menuString = null;

request.setCharacterEncoding("UTF-8");

response.setCharacterEncoding("UTF-8");

AllBook allBook = new AllBook();

Menu menu = allBook.getAllBooks();

PrintWriter out = response.getWriter();

JSONArray jsonObject = JSONArray.fromObject(menu);

try {

menuString = jsonObject.toString();

System.out.println("menuString=="+menuString);

} catch (Exception e) {

 

e.printStackTrace();

}

out.print(menuString);

}

 

}

 

 

前台页面显示

 

<script type="text/javascript">

Ext.onReady(function() {

var Tree = Ext.tree;

   

    var tree = new Tree.TreePanel({

        el:'tree-div',

        autoScroll:true,

        animate:true,

        enableDD:true,

        containerScroll: true,

        loader: new Tree.TreeLoader({

            dataUrl:'<%=path%>/BookServlet'

        })

    });

 

    // set the root node

    var root = new Tree.AsyncTreeNode({

        text: 'Root',

        draggable:false,

        id:'source'

    });

    tree.setRootNode(root);

 

    // render the tree

    tree.render();

    tree.expandAll();

});

</script>

</head>

<body>

<div id="tree-div"></div>

</body>

 

显示效果: