model1纯JSP（实现分页）

比眉伴天荒 2021-11-05 06:40 322阅读 0赞

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<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>登录界面</title>
    </head>
    <body>
    <form action="LoginCl.jsp" method="post">
    <table >
                    <tr><td>用户名</td><td><input type="text" name="username"/></td></tr>
                    <tr><td>密    码</td><td><input type="text" name="password"/></td></tr>
                    <tr><td><input type="submit" value="登录" /></td><td><input type="reset" value="清空"/></td></tr>
                </table>
    </form>
    </body>
    </html>

LoginCL.jsp

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改进版:

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标准版：

LoginCL.jsp

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Main.jsp

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实现分页版：

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LoginCl.jsp

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Welcom.jsp(分页)

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<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"
        import="java.sql.*"
        %>
    <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    </head>
    <body>
    欢迎来到新的页面！ <a href="Login.jsp">返回主页面</a>
       <hr/>
    <%
    //定义分页可以用到的变量
    int pageSize=3;
    int pageNow=1;
    int rowCount=0;
    int pageCount=0;
    String page1=request.getParameter("pageNow");
    if(page!=null){
        pageNow=Integer.parseInt(page1);
    }
    String name=request.getParameter("user");
    //查询得到
    Connection conn = null;
    PreparedStatement ps = null;
    ResultSet rs = null;
    try{
        Class.forName("com.mysql.jdbc.Driver");
        conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/user", "root", "123456");
    
        String sql = "select count(*) from user";
        ps = conn.prepareStatement(sql);
        // 结果
        rs = ps.executeQuery();
        if (rs.next()) {
         //next不要忘了
            rowCount=rs.getInt(1);
            out.print(rowCount);
        }     
        ps.close();
        rs.close();
        //计算PageCount
        if(rowCount%pageSize==0){
            pageCount=rowCount/pageSize;
        }else {
            pageCount=rowCount/pageSize+1;
        }
        out.print("pageCount="+pageCount);
        //查询出需要显示的页面
        if(rowCount>=pageNow*pageSize){
            sql="select *from user limit "+(pageNow-1)*pageSize+","+pageSize;        
        }
        else{
            sql="select *from user limit "+(pageNow-1)*pageSize+","+(rowCount-(pageNow-1)*pageSize);
        }
        out.print(sql);
                ps = conn.prepareStatement(sql);
        // 结果
        rs = ps.executeQuery();  
       %>
       <table border="1px" >
      <tr><td>用户ID</td><td>用户名</td><td>邮箱</td><td>等级</td><td>密码</td></tr>
       <%
       while(rs.next()){
          %>
          <tr><td><%=rs.getInt(1)%></td><td><%=rs.getString(2)%></td><td><%=rs.getString(3)%></td><td><%=rs.getInt(4)%></td><td><%=rs.getString(5)%></td></tr>
          <%  
       }
       %>
       </table>
       <%
       if(pageNow!=1){
       out.print("<a href='Welcom.jsp?pageNow="+(pageNow-1)+"'>上一页</a>");}
       //显示超链接
       for(int i=1;i<=pageCount;i++){
           out.print("<a href='Welcom.jsp?pageNow="+i+"'>["+i+"]</a>");
       }
       if(pageNow!=pageCount){
       out.print("<a href='Welcom.jsp?pageNow="+(pageNow+1)+"'>下一页</a>");}
        }catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                rs.close();
                ps.close();
                conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            }
    %>
    <hr/>
    </body>
    </html>

缺点分析;

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转载于:https://www.cnblogs.com/helloworld2019/p/11052328.html

[1591298-20190619171143369-1435164649.png]: /images/20211104/6550283b667246a397e024fab7cf2c30.png
[ContractedBlock.gif]: https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif
[ExpandedBlockStart.gif]: /images/20211104/e3a23dee0c4345fd87abe0005fc9fc0c.png
[1591298-20190619214740936-1417463959.png]: /images/20211104/b397e9a9110248afb68a75049e2b6f53.png