1、修改功能实现

     dao

     public int gradeAdd(Connection con,Grade grade)throws Exception{

          String sql="update t_grade set gradeName=?,gradeDesc=? where id=?";

          PreparedStatement pstmt=con.prepareStatement(sql);

          pstmt.setString(1, grade.getGradeName());

          pstmt.setString(2, grade.getGradeDesc());

          pstmt.setInt(3, grade.getId());

          return pstmt.executeUpdate();

     }

2、dialog对话框组件

    <div id="dig" class="easyui-dialog" style="width:400px;height:280px;padding:10px 20px;" closed="true" buttons="#dlg-buttons">

          <form id="fm" method="post" >

               <table>

                    <tr>

                         <td>班级名称：</td>

                         <td><input type="text" name="gradeName" id="gradeName" class="easyui-validatebox" required="true" ></td>

                    </tr>

                    <tr>

                         <td valign="top">班级描述：</td>

                         <td><textarea rows="7" cols="30" name="gradeDesc" id="gradeDesc" ></textarea></td>

                    </tr>

               </table>

          </form>

     </div>

     <div id="dlg-buttons">

          <a href="#" class="easyui-linkbutton" iconCls="icon-ok" >保存</a>

          <a href="#" class="easyui-linkbutton" iconCls="icon-cancel" >关闭</a>

     </div>

     <a href="javascript:openGradeAddDialog()" class="easyui-linkbutton" iconCls="icon-add" plain="true" >添加</a>|

     //添加标题

     function openGradeAddDialog(){

          $("#dig").dialog("open").dialog("setTitle","添加班级信息");

     }

3、关闭

     <a href="javascript:closeGradeDialog()" class="easyui-linkbutton" iconCls="icon-cancel" >关闭</a>

     function closeGradeDialog(){

          $("#dig").dialog("close");

          resetValue();

     }

4、重置

     function resetValue(){

          $("#gradeName").val("");

          $("#gradeDesc").val("");

     }

5、乱码（tomcat默认不是utf-8）

      request.setCharacterEncoding("utf-8");

6、添加

     function saveGrade(){

          $("#fm").form("submit",{

               url:url,

               onSubmit:function(){

                    return $(this).form("validate");

               },

               success:function(result){

                    if(result.errorMsg){

                         $.messager.alert("系统提示",result.errorMsg);

                         return;

                    }else{

                         $.messager.alert("系统提示","保存成功");

                         resetValue();

                         $("#dlg").dialog("close");

                         $("#dg").datagrid("reload");

                    }

               }

          });

     }

          request.setCharacterEncoding("utf-8");

          String gradeName=request.getParameter("gradeName");

          String gradeDesc=request.getParameter("gradeDesc");

          Grade grade=new Grade(gradeName,gradeDesc);

          if(StringUtil.isNotEmpty(id)){

               grade.setId(Integer.parseInt(id));

          }

          Connection con=null;

          try {

               con=dbUtil.getCon();

               int saveNums=0;

               JSONObject result=new JSONObject();

               if(StringUtil.isNotEmpty(id)){

                    saveNums=gradeDao.gradeModify(con, grade);

               }else{

                    saveNums=gradeDao.gradeAdd(con, grade);

               }

               if(saveNums>0){

                    result.put("success", "true");

               }else{

                    result.put("success", "true");

                    result.put("errorMeg", "删除失败");

               }

               ResponseUtil.write(response, result);

          } catch (Exception e) {

               // TODO Auto-generated catch block

               e.printStackTrace();

          }finally{

               try {

                    dbUtil.closeCon(con);

               } catch (Exception e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

               }

          }

     }

          public int gradeAdd(Connection con,Grade grade)throws Exception{

          String sql="insert into t_grade values(null,?,?)";

          PreparedStatement pstmt=con.prepareStatement(sql);

          pstmt.setString(1, grade.getGradeName());

          pstmt.setString(2, grade.getGradeDesc());

          return pstmt.executeUpdate();

          }

7、修改

     <a href="javascript:openGradeModifyDialog()" class="easyui-linkbutton" iconCls="icon-edit" plain="true" >修改</a>|

function openGradeModifyDialog(){

          var selectedRows=$("#dg").datagrid('getSelections');

          if(selectedRows.length!=1){

               $.messager.alert("系统提示","请选择一条要编辑的数据！");

               return;

          }

          var row=selectedRows[0];

          $("#dlg").dialog("open").dialog("setTitle","编辑班级信息");

          $("#fm").form("load",row);

          url="gradeSave?id="+row.id;

     }

          request.setCharacterEncoding("utf-8");

          String gradeName=request.getParameter("gradeName");

          String gradeDesc=request.getParameter("gradeDesc");

          String id=request.getParameter("id");

          Grade grade=new Grade(gradeName,gradeDesc);

          if(StringUtil.isNotEmpty(id)){

               grade.setId(Integer.parseInt(id));

          }

          Connection con=null;

          try {

               con=dbUtil.getCon();

               int saveNums=0;

               JSONObject result=new JSONObject();

               if(StringUtil.isNotEmpty(id)){

                    saveNums=gradeDao.gradeModify(con, grade);

               }else{

                    saveNums=gradeDao.gradeAdd(con, grade);

               }

               if(saveNums>0){

                    result.put("success", "true");

               }else{

                    result.put("success", "true");

                    result.put("errorMeg", "删除失败");

               }

               ResponseUtil.write(response, result);

          } catch (Exception e) {

               // TODO Auto-generated catch block

               e.printStackTrace();

          }finally{

               try {

                    dbUtil.closeCon(con);

               } catch (Exception e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

               }

          }

          public int gradeModify(Connection con,Grade grade)throws Exception{

          String sql="update t_grade set gradeName=?,gradeDesc=? where id=?";

          PreparedStatement pstmt=con.prepareStatement(sql);

          pstmt.setString(1, grade.getGradeName());

          pstmt.setString(2, grade.getGradeDesc());

          pstmt.setInt(3, grade.getId());

          return pstmt.executeUpdate();

          }