MVC(增删改查)

一.MVC(增删改查)

导入：

1.1、通用分页的jar、自定义mvc框架、自定义标签 导入之前写好的pageTag、自定义mvc.xml

导入Jar

通用的增删改方法

BaseDao

 1     /**
 2      * 
 3      * @param sql 决定增删改的一种
 4      * @param attrs 决定？位置 new String[]{"bid,"bname"}
 5      * @param t 要操作的实体
 6      * @return
 7      * @throws Exception 
 8      * @throws NoSuchFieldException 
 9      */
10     public int executeUpdate (String sql,String[] attrs,T t) throws NoSuchFieldException, Exception {
11         Connection con=DBAccess.getConnection();
12         PreparedStatement ps=con.prepareStatement(sql);
13         for(int i=1;i<=attrs.length;i++) {
14         Field f=t.getClass().getDeclaredField(attrs[i-1]);
15         f.setAccessible(true);
16         ps.setObject(i, f.get(t));
17         }
18         int num=ps.executeUpdate();
19         DBAccess.close(con, ps, null);        
20         return num;
21     }
22

dao方法

BookDao

 1 public class BookDao extends BaseDao<Book>{
 2     /**
 3      * 查询所有
 4      * @param book
 5      * @param pageBean
 6      * @return
 7      * @throws Exception
 8      */
 9   public List<Book> list(Book book,PageBean pageBean) throws Exception{
10       String sql="select * from t_mvc_book where true";
11       String bname=book.getBname();
12       int bid=book.getBid();
13       if(StringUtils.isNotBlank(bname)) {
14           sql+=" and bname like '%"+bname+"%'";
15       }
16       if(bid!=0) {
17           sql+=" and bid="+bid;
18       }
19       return super.executeQuery(sql, Book.class, pageBean); 
20       
21   }
22   /**
23    * 修改
24    * @param book
25    * @return
26  * @throws Exception 
27  * @throws NoSuchFieldException 
28    */
29   public int upde(Book book) throws NoSuchFieldException, Exception {
30       String sql="update t_mvc_book set bname=?,price=? where bid=?";
31   return super.executeUpdate(sql, new String[] {"bname","price","bid"}, book);
32   }
33   
34   /**
35    * 新增
36    * @param book
37    * @return
38  * @throws Exception 
39  * @throws NoSuchFieldException 
40    */
41   public int add(Book book) throws NoSuchFieldException, Exception {
42       String sql="insert into t_mvc_book values(?,?,?)";
43       System.out.println(sql);
44   return super.executeUpdate(sql, new String[] {"bid","bname","price"}, book);
45   }
46   
47   /**
48    * 删除
49    * @param book
50    * @return
51  * @throws Exception 
52  * @throws NoSuchFieldException 
53    */
54   public int del(Book book) throws NoSuchFieldException, Exception {
55       String sql="delete from t_mvc_book where bid=?";
56       
57   return super.executeUpdate(sql, new String[] {"bid"}, book);
58   }
59 }

Book实体类

 1 package mvc.entity;
 2 
 3 public class Book {
 4     private int bid;
 5     private String bname;
 6     private float price;
 7 
 8     @Override
 9     public String toString() {
10         return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
11     }
12 
13     public int getBid() {
14         return bid;
15     }
16 
17     public void setBid(int bid) {
18         this.bid = bid;
19     }
20 
21     public String getBname() {
22         return bname;
23     }
24 
25     public void setBname(String bname) {
26         this.bname = bname;
27     }
28 
29     public float getPrice() {
30         return price;
31     }
32 
33     public void setPrice(float price) {
34         this.price = price;
35     }
36 
37     public Book(int bid, String bname, float price) {
38         super();
39         this.bid = bid;
40         this.bname = bname;
41         this.price = price;
42     }
43 
44     public Book() {
45         super();
46     }
47 
48     
49 }

BookAction调用通用分页，自定义mvc框架，自定义标签

  1 package com.mvc.web;
  2 
  3 import java.util.List;
  4 
  5 import javax.servlet.http.HttpServlet;
  6 import javax.servlet.http.HttpServletRequest;
  7 import javax.servlet.http.HttpServletResponse;
  8 
  9 import com.mvc.dao.BookDao;
 10 import com.mvc.entity.Book;
 11 import com.mvc.framework.ActionSupport;
 12 import com.mvc.framework.ModelDrivern;
 13 import com.mvc.util.PageBean;
 14 
 15 public class BookAction extends ActionSupport implements ModelDrivern<Book>{
 16      private Book book=new Book();
 17      private BookDao bookdao=new BookDao();
 18      /**
 19       * 分页查询
 20       * @param request
 21       * @param response
 22       * @return
 23       * @throws Exception
 24       */
 25     
 26      public String list(HttpServletRequest request,HttpServletResponse response) throws Exception {
 27          PageBean pageBean=new PageBean();
 28          pageBean.setRequest(request);
 29          List<Book> list = this.bookdao.list(book, pageBean);
 30          request.setAttribute("booklist", list);
 31          request.setAttribute("pagebean", pageBean);
 32          return "list";
 33      }
 34      
 35      /**
 36       * 
 37       * 跳转到增加或修改页面
 38       * @param request
 39       * @param response
 40       * @return
 41       * @throws Exception
 42       */
 43      public String preSave(HttpServletRequest request,HttpServletResponse response) {
 44         //bid的类型是int类型，而int类型的默认值是0，如果jsp未传递bid的参数值那么bid=0;
 45          if(book.getBid()==0) {
 46             System.out.println("增加逻辑");
 47             
 48           }
 49         else {
 50             //修改数据回显
 51             Book b;
 52             try {
 53                 b = this.bookdao.list(book, null).get(0);
 54                 request.setAttribute("book", b);
 55             } catch (Exception e) {
 56                 // TODO Auto-generated catch block
 57                 e.printStackTrace();
 58             }
 59             
 60         }
 61          return "edit";
 62       
 63      
 64      }
 65      
 66      /**
 67       * 新增
 68       * @param request
 69       * @param response
 70       * @return
 71       * @throws Exception
 72       */
 73      public String add(HttpServletRequest request,HttpServletResponse response) throws Exception {
 74         //新增完了之后刷新页面
 75         this.bookdao.add(book);
 76          return "tolist";
 77      
 78      }
 79      
 80       /**
 81        * 修改
 82        * @param request
 83        * @param response
 84        * @return
 85        * @throws Exception
 86        */
 87      public String upde(HttpServletRequest request,HttpServletResponse response) throws Exception {
 88          //修改完了之后刷新页面
 89           this.bookdao.upde(book);
 90           return "tolist";
 91       
 92       }
 93      /**
 94       * 删除
 95       * @param request
 96       * @param response
 97       * @return
 98       * @throws Exception
 99       */
100      public String del(HttpServletRequest request,HttpServletResponse response) throws Exception {
101           //删除之后刷新页面
102           this.bookdao.del(book);
103           return "tolist";
104        }
105      
106     @Override
107     public Book getModel() {
108         // TODO Auto-generated method stub
109         return book;
110     }
111      
112 }

配置mvc.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2     <!--
 3         config标签:可以包含0~N个action标签
 4     -->
 5 <config>
 6     <!--  <action path="/addCal" type="com.mvc.web.AddCalAction">-->
 7         <!--<forward name="res" path="/res.jsp" redirect="false" />-->
 8     <!--</action>-->
 9     
10     <!--<action path="/delCal" type="com.mvc.web.DelCalAction">-->
11     <!--    <forward name="res" path="/res.jsp" redirect="false" />-->
12     <!--</action>-->
13     
14     <!--<action path="/mulCal" type="com.mvc.web.MulCalAction">-->
15     <!--    <forward name="res" path="/res.jsp" redirect="false" />-->
16     <!--</action>-->
17     
18     <!--<action path="/divCal" type="com.mvc.web.DivCalAction">-->
19     <!--    <forward name="res" path="/res.jsp" redirect="false" />-->
20     <!--</action>-->
21     
22     <action path="/cal" type="com.mvc.web.CalAction">
23         <forward name="res" path="/res.jsp" redirect="false" />
24     </action>
25     
26     <action path="/book" type="com.mvc.web.BookAction">
27         <forward name="list" path="/bookList.jsp" redirect="false" />
28                 <forward name="edit" path="/bookEdit.jsp" redirect="false" />
29         <forward name="toList" path="/book.action?methodName=list"></forward>
30     </action>
31     
32 
33 </config>

页面代码

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3     <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
 4     <%@ taglib uri="/XuFanQi" prefix="x" %>
 5 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 6 <html>
 7 <head>
 8 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 9 <title>Insert title here</title>
10 </head>
11 <body>
12 <h2>小说目录</h2>
13     <br>
14 
15     <form action="${pageContext.request.contextPath}/book.action?methodName=list"
16         method="post">
17         书名：<input type="text" name="bname"> <input type="submit"
18             value="确定">
19             <input type="hidden" name="bname">
20     </form>
21     <a href="${pageContext.request.contextPath}/book.action?methodName=preSave">增加</a>
22     <table border="1" width="100%">
23         <tr>
24             <td>编号</td>
25             <td>名称</td>
26             <td>价格</td>
27             <del>操作</del>
28         </tr>
29         <c:forEach items="${bookList }" var="b">
30             <tr>
31                 <td>${b.bid }</td>
32                 <td>${b.bname }</td>
33                 <td>${b.price }</td>
34                 <td>
35                     <a href="${pageContext.request.contextPath}/book.action?methodName=preSave&&bid=${b.bid}">修改</a>&nbsp;&nbsp;&nbsp;
36                                 <a href="${pageContext.request.contextPath}/book.action?methodName=dele&&bid=${b.bid}">删除</a>&nbsp;&nbsp;&nbsp;
37 
38                 
39                 </td>
40             </tr>
41         </c:forEach>
42     </table>
43 
44     <x:Page pageBean="${pageBean }"></x:Page>
45 </body>
46 </html>

新增修改页面

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10 <form action="${pageContext.request.contextPath}/book.action" method="post">
11    <input type="hidden" name="methodName" value="${book.bname == null?'add':'edit' }">
12    书籍ID:<input type="text" name="bid" value="${book.bid }"><br>
13    书籍名称:<input type="text" name="bname" value="${book.bname }"><br>
14    书籍价格:<input type="text" name="price" value="${book.price }"><br>
15    <input type="submit">
16 </form>
17 </body>
18 </html>

运行效果

查询

新增

修改

删除

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原文地址：https://www.cnblogs.com/xcn123/p/11102877.html