Struts2+Datagrid表格显示（可显示多表内容）

概述

　　最近学到EasyUI的Datagrid数据网格，然后就做了一个小例子，中间层利用Struts2来完成，DAO层用的是Hibernate。

数据库

　　数据库涉及到stuednt（name,noid,password,hobby,tno）表和teacher（tno，tname）表；实体的映射和实体之间关系的配置用的是注解的方式(mapper不能忘哦)。

 @Entity
 @Table
 public class Teacher {
     private String tname;
     @Id
     private String tno;
 //set/get方法略
 }

Teacher.java

 @Entity
 @Table
 public class Student {

     private String name;
     @Id
     private String noid;
     private String password;
     private String hobby;
     @ManyToOne(cascade=CascadeType.ALL,fetch=FetchType.EAGER)
     @JoinColumn(name="tno",nullable=false,insertable=false,updatable=false)
         private Teacher teacher;
     //set/get方法略

 }    

Student.java

　　中间对数据库一个是获得所有的数据库的总条数，一个实现按条件分页查询代码如下：

 public List<Student> queryAllStudent(){
         Session session = factory.openSession();
         Transaction transaction = session.beginTransaction();
         String sql = "from Student";
         List<Student> list = null ;
         try {
              list = (List<Student>) session.createQuery(sql).list();
              transaction.commit();
         } catch (HibernateException e) {
             transaction.rollback();
             // TODO Auto-generated catch block
             e.printStackTrace();
         }finally{

             session.close();
         }
         return list;
     }
     //通过学号姓名查询
     public List<Student> queryStudentByNameOrNoid(String queryName,String queryNoid,int page,int rows){
         String sql = "from Student where 1=1 ";
         List<Student> list = null ;
         boolean ss = null==queryName;
         if((null==queryName) || ("".equals(queryName))){
             sql = sql + "and to_char(1)=?";
             queryName = "1";
         }else{
             sql = sql + "and name=?";
         }
         if((null == queryNoid) || ("".equals(queryNoid))){
             sql = sql + "and to_char(1)=?";
             queryNoid = "1";

         }else{
             sql = sql + "and noid=?";
         }
         Session session = factory.openSession();
         Transaction transaction = session.beginTransaction();
         try {
                  list = (List<Student>) session.createQuery(sql).setParameter(0, queryName)
                          .setParameter(1, queryNoid)
                          .setFirstResult((page-1)*rows)
                          .setMaxResults(rows).list();
              transaction.commit();
         } catch (HibernateException e) {
             transaction.rollback();
             // TODO Auto-generated catch block
             e.printStackTrace();
         }finally{

             session.close();
         }
         return list;
     }
 //其他代码略

中间层（Struts2）

　　中间的配置文件内容（struts.xml）为：

 <struts>
     <constant name="struts.custom.i18n.resources" value="info">
     </constant>
     <constant name="struts.enable.DynamicMethodInvocation" value="true"></constant>
     <package name="hm" namespace="/" extends="struts-default,json-default">
         <action name="queryStudentByNameOrNoid" class="com.lt.action.StudentAction" method="queryStudentByNameOrNoid">
             <result name="success" type="json">
             <param name="root">s</param>
             <param name="excludeProperties">success</param></result>
             <result name="error"></result>
         </action>
 </package>
 </struts>
 //中间其他配置内容略

　　Action的方法为：

 public class StudentAction extends ActionSupport {
     private Map <String,Object>request;  

         private Map <String,Object>session;  

         private Map <String,Object>application;
     private Map<String,Object> s ;
     private Student student;

     private String queryName;
     private String queryNoid;

     private int page;
     private int rows;
     StudentDao studentDao = new StudentDao(); 

 public String queryStudentByNameOrNoid(){
          List<Student> student = new ArrayList<>();
          List<Student> student1 = new ArrayList<>();
          List<Teacher> student2 = new ArrayList<>();
          List<Object> sl = new ArrayList<>();
          s = new HashMap<String, Object>();
          student = studentDao.queryStudentByNameOrNoid(queryName, queryNoid,page,rows);
          student1 = studentDao.queryAllStudent();
          s.put("total", student1.size());
          System.out.println(student1.size());
          s.put("rows", student);
          return SUCCESS;
      }

 //其他略
 }

　页面内容：

 <%@ page language="java" contentType="text/html; charset=utf-8"
     pageEncoding="utf-8"%>
 <!DOCTYPE html>
 <html>
 <head>
     <meta charset="UTF-8">
     <title>DataGrid Complex Toolbar - jQuery EasyUI Demo</title>
     <link rel="stylesheet" type="text/css" href="jquery-easyui-1.5.3/themes/default/easyui.css">
     <link rel="stylesheet" type="text/css" href="jquery-easyui-1.5.3/themes/icon.css">
     <script type="text/javascript" src="jquery-easyui-1.5.3/jquery.min.js"></script>
     <script type="text/javascript" src="jquery-easyui-1.5.3/jquery.easyui.min.js"></script>
 </head>
 <body>
 <script type="text/javascript">
     function lal(){
         queryName = $("#queryName").val();
         queryNoid = $("#queryNoid").val();
         //var url = "queryStudentByNameOrNoid.action";
         //$("#detilfrom").attr("url",url);
         $("#detilfrom").datagrid('load',{queryName:queryName,queryNoid:queryNoid});
         }

 </script>
     <h2>DataGrid Complex Toolbar</h2>

     <div style="margin:20px 0;"></div>
     <table id="detilfrom" class="easyui-datagrid" title="学生列表" style="width:450px;height:300px"
      pagination="true"
             data-options="rownumbers:true,singleSelect:true,url:'queryStudentByNameOrNoid.action',method:'get',toolbar:'#tb,#ft',footer:'#ft'">
         <thead>
             <tr>
                 <th data-options="field:'name',width:80">姓名</th>
                 <th data-options="field:'noid',width:100">学号</th>
                 <th data-options="field:'password',width:80,align:'right'">密码</th>
                 <th data-options="field:'hobby',width:80,align:'right'">爱好</th>
                 <th data-options="field:'tname',width:80,align:'right', formatter: function (value, rec) {
                         return rec.teacher['tname'];}">教师姓名</th>
             </tr>
         </thead>
     </table>
     <div id="tb" style="padding:2px 5px;">
         姓名: <input id="queryName"  style="width:110px">
         学号: <input id="queryNoid"  style="width:110px">
         <a href="#" class="easyui-linkbutton" iconCls="icon-search" onclick="lal()">Search</a>
     </div>
     <div id="ft" style="padding:2px 5px;">
         <a href="#" class="easyui-linkbutton" iconCls="icon-add" plain="true"></a>
         <a href="#" class="easyui-linkbutton" iconCls="icon-edit" plain="true"></a>
         <a href="#" class="easyui-linkbutton" iconCls="icon-save" plain="true"></a>
         <a href="#" class="easyui-linkbutton" iconCls="icon-cut" plain="true"></a>
         <a href="#" class="easyui-linkbutton" iconCls="icon-remove" plain="true"></a>
     </div>
 </body>
 </html>

　　需要注意的是：

　　1.datagrid接收的数据格式为（从EasyUI的Demo中copy）：

{"total":28,"rows":[
	{"productid":"FI-SW-01","unitcost":10.00,"status":"P","listprice":36.50,"attr1":"Large","itemid":"EST-1"},
	{"productid":"K9-DL-01","unitcost":12.00,"status":"P","listprice":18.50,"attr1":"Spotted Adult Female","itemid":"EST-10"},
	{"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":28.50,"attr1":"Venomless","itemid":"EST-11"},
	{"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":26.50,"attr1":"Rattleless","itemid":"EST-12"},
	{"productid":"RP-LI-02","unitcost":12.00,"status":"P","listprice":35.50,"attr1":"Green Adult","itemid":"EST-13"},
	{"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":158.50,"attr1":"Tailless","itemid":"EST-14"},
	{"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":83.50,"attr1":"With tail","itemid":"EST-15"},
	{"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":63.50,"attr1":"Adult Female","itemid":"EST-16"},
	{"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":89.50,"attr1":"Adult Male","itemid":"EST-17"},
	{"productid":"AV-CB-01","unitcost":92.00,"status":"P","listprice":63.50,"attr1":"Adult Male","itemid":"EST-18"}
],"footer":[
	{"unitcost":19.80,"listprice":60.40,"productid":"Average:"},
	{"unitcost":198.00,"listprice":604.00,"productid":"Total:"}
]}

　　其中total和rows必不可少，total为总条数，rows为内容。

　　2.在上述的数据格式中若有嵌套的json数据，要想在表格中展示可以利用formatter属性（见jsp页面中的‘’教师姓名‘’列）；我的表格中的数据格式为（student实体属性中包含teache属性，为俩张变中的内容，现在利用formatter可以全部显示）

对于datagrid显示多表数据也可以利用后台数据输出格式来控制（可以利用mybatis查询的结果控制）：

 {"total":2,"rows":[{"hobby":"123","name":"刘晓杰","noid":"123","password":"123","teacher":{"tname":"小刘","tno":"012"}},{"hobby":"456","name":"拉拉","noid":"456","password":"456","teacher":{"tname":"小拉","tno":"125"}}]}

　　3.下面是查询的标签设置，若像下面书写，href为#时，点击查询只发送一条请求，若为其他则会发送俩次请求，导致查询结果出错。查看其他的解决datagrid发送俩次请求的解决方式—— 一种是去掉class，一种是去除url设置。由于和此处的用法有出入，因此没用采用。

<a href="#" class="easyui-linkbutton" iconCls="icon-search" onclick="lal()">Search</a>

参考内容：

http://www.cnblogs.com/easypass/archive/2012/12/16/2820996.html

http://blog.csdn.net/qiushisoftware/article/details/37991591