Javaweb简易程序的完善：
今日完善了上周测试的web程序修改功能，做出了最终的修改功能，对于修改功能一直是我以前不太会的点，之前我会修改的函数的编写，但是不太明确在jsp文件中参数的传递，经常导致页面显示修改成功而数据库没有改变的显现，曾经一度想过将修改做成删除加增加，但是今天我在经过学习别人在修改的jsp文件中的操作，学会了修改的操作，完善了之前的测试程序。
修改部分代码
Test.java中修改部分代码:
1 public void revisedata(String biao0,String zheng,String tian,String biao)
2 {
3 Connection connection = getConnection();
4 PreparedStatement preparedStatement=null;
5 try {
6
7 String sql = "update bao set 标题=?,内容=?,坚持天数=? where 标题=?";
8 preparedStatement=connection.prepareStatement(sql);
9 preparedStatement.setString(1,biao);
10 preparedStatement.setString(2,zheng);
11 preparedStatement.setString(3,tian);
12 preparedStatement.setString(4,biao0);
13 preparedStatement.executeUpdate();
14
15 } catch (SQLException e) {
16 e.printStackTrace();
17 }finally{
18 close(preparedStatement);
19 close(connection);
20 }
21 }
jsp文件中修改部分:
revise.jsp
1 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 2 <html> 3 <head> 4 <title>修改</title> 5 </head> 6 <body> 7 <form action="revisejudge.jsp" method="get"> 8 <p style="text-align:center;color: black; font-family: 宋体; font-size: 20px"> 9 <br> 要修改的日记标题: <input type="text" name="biao" /> <br> 10 <br><input type="submit" value="确定" /> 11 <br> <input type="button" value="返回菜单" onclick="location.href='index.jsp'" /> <br> 12 </p> 13 </form> 14 </body> 15 </html>
revisejudge.jsp
1 <%@ page language="java" import="java.sql.*" contentType="text/html; charset=UTF-8"
2 pageEncoding="UTF-8"%>
3 <!DOCTYPE html>
4 <html>
5 <head>
6 <meta charset="UTF-8">
7 </head>
8 <body>
9
10 <jsp:useBean id="util" class="test.Test" scope="page" />
11 <%
12 String biao=(String)request.getParameter("biao");
13 if(biao==""){
14 out.print("<script language='javaScript'> alert('输入为空'); window.history.back(-1); </script>");
15 }
16 else if(!util.isSame(biao))
17 {
18 out.print("<script language='javaScript'> alert('该信息不存在'); window.history.back(-1); </script>");
19 }
20 else{
21 %>
22 <table border="1"style="text-align:center;">
23 <tr>
24 <td align="center" width=6%>标题</td>
25 <td align="center" width=8%>正文</td>
26 <td align="center" width=10%>天数</td>
27 <td align="center" width=3%>修改</td>
28 </tr>
29 <%
30 Connection connection = util.getConnection();
31 PreparedStatement preparedStatement=null;
32 ResultSet rs=null;
33 try {
34 String sql = "select * from bao";
35 preparedStatement=connection.prepareStatement(sql);
36 rs=preparedStatement.executeQuery();
37 while(rs.next()){
38 if(biao.equals(rs.getObject(1)))
39 {
40 %>
41 <tr>
42 <td align="center"><%=rs.getObject(1) %></td>
43 <td align="center"><%=rs.getObject(2) %></td>
44 <td align="center"><%=rs.getObject(3) %></td>
45 <td align="center"><a style="color:blue" href='revisejudge1.jsp?biao0=<%=rs.getObject(1) %>' onclick="javascript:return del()">修改</a> </td>
46 </tr>
47
48 <%
49 }
50 }
51 } catch (SQLException e) {
52 e.printStackTrace();
53 }finally{
54 util.close(rs);
55 util.close(preparedStatement);
56 util.close(connection);
57 }
58 %>
59 </table>
60 <%
61 }
62 %>
63 <%--
64 界面提示
65 --%>
66 <script>
67 function del(){
68 var r = confirm("确定修改这条吗？")
69 if (r == true) {
70 return true;
71 } else {
72 return false;
73 }
74 }
75 </script>
76 <p style="text-align:center;color: black; font-family: 宋体; font-size: 20px">
77 <br> <input type="button" value="返回菜单" onclick="location.href='index.jsp'" /> <br>
78 </p>
79 </body>
80 </html>
revisejudge1.jsp
1 <%@ page language="java" import="java.sql.*" contentType="text/html; charset=UTF-8"
2 pageEncoding="UTF-8"%>
3 <!DOCTYPE html>
4 <html>
5 <head>
6 <meta charset="UTF-8">
7 </head>
8 <body>
9 <jsp:useBean id="util" class="test.Test" scope="page" />
10 <%
11 String biao0=(String)request.getParameter("biao0");
12 session.setAttribute("biao0",biao0);
13 %>
14 <table border="1"style="text-align:center;">
15 <tr>
16 <td align="center" width="8%">标题</td>
17 <td align="center" width=8%>正文</td>
18 <td align="center" width=10%>天数</td>
19
20 </tr>
21 <%
22 Connection connection = util.getConnection();
23 PreparedStatement preparedStatement=null;
24 ResultSet rs=null;
25 try {
26 String sql = "select * from bao";
27 preparedStatement=connection.prepareStatement(sql);
28 rs=preparedStatement.executeQuery();
29 while(rs.next()){
30 if(biao0.equals(rs.getObject(1)))
31 {
32 %>
33 <tr>
34 <td align="center"><%=rs.getObject(1)%></td>
35 <td align="center"><%=rs.getObject(2) %></td>
36 <td align="center"><%=rs.getObject(3) %></td>
37 </tr>
38 <%
39 }
40 }
41 } catch (SQLException e) {
42 e.printStackTrace();
43 }finally{
44 util.close(rs);
45 util.close(preparedStatement);
46 util.close(connection);
47 }
48 %>
49 </table>
50
51 <form action="revisejudge2.jsp" method="get">
52 <br>
53 <br>
54 修改信息
55 <br>
56 <br>
57 标题:
58 <br>
59 <input type="text" name="biao">
60 <br>
61 <br>
62 正文:
63 <br>
64 <textarea style="width: auto" name="zheng"></textarea>
65 <br>
66 天数:
67 <br>
68 <input type="text" name="tian">
69 <br><input type="submit" value="提交" />
70 <br>
71 <br> <input type="button" value="返回菜单" onclick="location.href='index.jsp'" /> <br>
72 </form>
73 </body>
74 </html>
revisejudge2.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8"
2 pageEncoding="UTF-8"%>
3 <!DOCTYPE html>
4 <html>
5 <head>
6 <meta charset="UTF-8">
7 </head>
8 <body>
9 <jsp:useBean id="util" class="test.Test" scope="page" />
10 <%
11 request.setCharacterEncoding("UTF-8");
12 String biao0=(String)session.getAttribute("biao0");
13 String biao=(String)request.getParameter("biao");
14 String zheng=(String)request.getParameter("zheng");
15 String tian=(String)request.getParameter("tian");
16
17 if(biao==""||zheng==""||tian=="")
18 {
19 out.print("<script language='javaScript'> alert('输入为空');window.history.back(-1);</script>");
20 }
21 else
22 {
23 util.revisedata(biao0,zheng,tian,biao);
24 out.print("<script language='javaScript'> alert('修改成功');</script>");
25 response.setHeader("refresh", "0;url=search.jsp");
26 }
27 %>
28 <p style="text-align:center;color: black; font-family: 宋体; font-size: 20px">
29 <br> <input type="button" value="返回菜单" onclick="location.href='index.jsp'" /> <br>
30 </p>
31 </body>
32 </html>
标签：总结,10,preparedStatement,20,String,星期二,第三周,修改,jsp From： https://www.cnblogs.com/sgle0722/p/17166239.html