Jsp&Servlet入门级项目全程实录第4讲

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1、添加搜索、添加、修改、删除按钮
<div id="tb">
          <div>
               <a href="#" class="easyui-linkbutton" iconCls="icon-add" plain="true" >添加</a>|
               <a href="#" class="easyui-linkbutton" iconCls="icon-edit" plain="true" >修改</a>|
               <a href="javascript:deleteGrade()" class="easyui-linkbutton" iconCls="icon-remove" plain="true" >删除</a>
          </div>
          <div>&nbsp;班级名称:<input type="text" name="s_gradeName" id="s_gradeName" /><a href="javascript:searchGrade()" class="easyui-linkbutton" iconCls="icon-search" plain="true" >搜索</a></div>
     </div>

2、实现搜索功能
     dao
     public ResultSet gradeList(Connection con,PageBean pageBean,Grade grade)throws Exception{
          StringBuffer sb=new StringBuffer("select * from t_grade");
          if(StringUtil.isNotEmpty(grade.getGradeName())){
               sb.append(" and gradeName like '%"+grade.getGradeName()+"%'");
          }
          if(pageBean!=null){
               sb.append(" limit "+pageBean.getStart()+","+pageBean.getRows());
          }
          PreparedStatement pstmt=con.prepareStatement(sb.toString().replaceFirst("and", "where"));
          return pstmt.executeQuery();
     }

     封装
     String gradeName=request.getParameter("gradeName");
          if(gradeName==null){
               gradeName="";
          }
     Grade grade=new Grade();
     grade.setGradeName(gradeName);

     前端
     <a href="javascript:searchGrade()" class="easyui-linkbutton" iconCls="icon-search" plain="true" >搜索</a>

     function searchGrade(){
          $('#dg').datagrid('load',{
               gradeName:$('#s_gradeName').val()
          })
     }

3、删除功能实现
     dao
     /**
     * delete from tableName where field in(1,3,5)
     * @param con
     * @param delIds
     * @return
     * @throws Exception
     */
     public int gradeDelect(Connection con,String delIds)throws Exception{
          String sql="delete from t_grade where id in("+delIds+")";
          PreparedStatement pstmt=con.prepareStatement(sql);
          return pstmt.executeUpdate();
     }

     删除Servlet配置web.xml
     <servlet>
    <servlet-name>gradeDeleteServlet</servlet-name>
    <servlet-class>com.java1234.web.GradeDeleteServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>gradeDeleteServlet</servlet-name>
    <url-pattern>/gradeDelete</url-pattern>
  </servlet-mapping> 

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

          Connection con=null;
          try {
               con=dbUtil.getCon();
               JSONObject result=new JSONObject();
               int delNums=gradeDao.gradeDelect(con, delIds);
               if(delNums>0){
                    result.put("success", "true");
                    result.put("delNums", delNums);
               }else{
                    result.put("errorMeg", "删除失败");
               }
               result.put("delNum", delNums);
               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();
               }
          }
     }

     前端
     <a href="javascript:deleteGrade()" class="easyui-linkbutton" iconCls="icon-remove" plain="true" >删除</a>

     function deleteGrade(){
          var selectedRows=$("#dg").datagrid('getSelections');
          if(selectedRows.length==0){
               $.messager.alert("系统提示","请选择要删除的数据！");
               return;
          }
          var strIds=[];
          for(var i=0;i<selectedRows.length;i++){
               strIds.push(selectedRows[i].id);
          }
          var ids=strIds.join(",");
          $.messager.confirm("系统提示","您确认要删掉这<font color=red>"+selectedRows.length+"</font>条数据吗？",function(r){
               if(r){
                    $.post("gradeDelete",{delIds:ids},function(result){
                         if(result.success){
                              $.messager.alert("系统提示","您已成功删除<font color=red>"+result.delNum+"</font>条数据!");
                              $("#dg").datagrid("reload");
                         }else{
                              $.messager.alert("系统提示",result.errorMsg);
                         }
                    },"json");
               }
          });
     }