Jsp&Servlet入门级项目全程实录第5讲

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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();
          }