玩转Web之easyui(二)-----easy ui 异步加载生成树节点（Tree），点击树生成tab(选项卡)

关于easy ui 异步加载生成树及点击树生成选项卡，这里直接给出代码，重点部分代码中均有注释

前台：

$('#tree').tree({

url: '../servlet/School_Tree?id=-1',  //向后台传送id,获取根节点
lines:true,
onBeforeExpand:function(node,param){
$('#tree').tree('options').url = "../servlet/School_Tree?id=" + node.id;  //动态获取节点
},
loadFilter: function(data){
if (data.msg){
return data.msg;
} else {
return data;
}
},
onClick:function(node){                      //节点的点击事件
var url='information_'+node.id+'.jsp';
tab(node.text,url);

}

});

function tab(text,url) {
if ($("#tabs").tabs('exists', text)) {   //若选项卡已存在，选择该选项卡
$("#tabs").tabs('select', text);
} else {
var content = "<iframe frameborder='0' scrolling='auto' style='width:100%;height:100%' src="
+ url + "></iframe>";

$("#tabs").tabs('add', {   //生成新的选项卡，
title : text,
closable : true,
content :content,

});
}
}

servlet:

package thejavabean;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;

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 net.sf.json.JSONObject;

public class School_Tree extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
String theIdString = request.getParameter("id");//父节点id
int id=Integer.parseInt(theIdString);
List<School> list=schoolTree(id);  //获取以id为父节点的数据
String sc="[";
for(School school:list){
sc+="{";
List<School> l=schoolTree(school.getId());  //判断id节点的儿子节点是否有儿子节点，即判断school中的数据是否为根节点
if(l.size()!=0){
sc+=String.format("\"id\": \"%s\", \"text\": \"%s\", \"state\": \"closed\"", school.getId() ,school.getName());
}else{
sc+=String.format("\"id\": \"%s\", \"text\": \"%s\", \"state\": \"\"", school.getId() ,school.getName());
}
sc+="},";
}
sc=sc.substring(0, sc.length() - 1);
sc+="]";
JSONObject  jobj = new JSONObject();
jobj.put("msg",sc);
response.getWriter().write(jobj.toString());
System.out.println(jobj.toString());

}
public List<School> schoolTree(int id){
StudentManage sm=new StudentManage();
School school=new School();
school.setId(id);
return sm.SchoolTree(school);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);

}

}

javabean:

package thejavabean;

public class School {

private int id;
private int pid;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getPid() {
return pid;
}
public void setPid(int pid) {
this.pid = pid;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}

}

public List<School> SchoolTree(School school) {
List<School> list = null;
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "";

try {
list = new ArrayList<School>();
conn = dbc.getConnection();
sql = "SELECT id,pid,name FROM SchoolManage where pid= "+school.getId();
sql.toUpperCase();
ps = conn.prepareStatement(sql);
rs = ps.executeQuery();
School s = null;
while (rs.next()) {
s = new School();
s.setId(rs.getInt("id"));
s.setPid(rs.getInt("pid"));
s.setName(rs.getString("name"));
list.add(s);
}
} catch (SQLException e) {
e.printStackTrace();
}finally {
dbc.colseDB(conn, ps, rs);
}
return list;
}

再来说一下数据表，共有三个字段，id，pid，name,大家可以自己写个数据表进行测试，还有DB是我简单封装过的，大家可以稍微结合自己的情况进行修改