学生管理系统的添加

1:后台方法的实现

//班级的添加的实现    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();    }    //班级的修改的实现    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.getGradeDesc());        pstmt.setString(2, grade.getGradeDesc());        pstmt.setInt(3, grade.getId());                        return pstmt.executeUpdate();    }

2：在新建一个servlet类，建好这个类之后就再web.xml配置：

           
      
       gradeSaveServlet
            
      
       com.fxr.web.GradeSaveServlet
        
         
           
      
       gradeSaveServlet
            
      
       /gradeSave
        
     

3：编写前台的界面：

1. 首先引入JQuery的easyui-dialog对话框

easyui-validatebox表单验证功能

对话框的代码：

         
     
                  
      
           
       
                              
         
                              
班级名称：
                              
                               
                               
                              
班级描述：
                              
                    
                                                               
       
                           
      
                 
     
        
     
        
      保存        
      关闭    
     

用Javascript做点击添加按钮的操作弹出对话框：

添加

function openGradeAddDialog(){        $("#dlg").dialog("open").dialog("setTitle","添加班级信息");        url="gradeSave";//提交给那个servlet处理    }

同样的方式修改的对话框：

修改

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;    }

保存的按钮操作：

     
        
      保存        
      关闭    
     

保存的javascript方法的实现：

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");                }            }        });    }

function resetValue(){

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

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

}

 后台servlet的代码的实现：

package com.fxr.web;import java.io.IOException;import java.sql.Connection;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import net.sf.json.JSONObject;import com.fxr.dao.GradeDao;import com.fxr.model.Grade;import com.fxr.util.DbUtil;import com.fxr.util.ResponseUtil;import com.fxr.util.StringUtil;public class GradeSaveServlet extends HttpServlet{    DbUtil dbUtil=new DbUtil();    GradeDao gradeDao=new GradeDao();        @Override    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        this.doPost(request, response);    }    @Override    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        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("errorMsg", "保存失败");            }            ResponseUtil.write(response, result);        }catch(Exception e){            e.printStackTrace();        }finally{            try {                dbUtil.closeCon(con);            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }    }        }