共计 6505 个字符，预计需要花费 17 分钟才能阅读完成。
1、分页数据流转流程图
PageBean.java
import java.util.List;
public class PageBean<T> {private List<T> beanList;// 当前页记录数, 需要传递
private int tr;// 总记录数, 需要传递
private int pc;// 当前页码, 需要传递
private int ps;// 每页记录数, 需要传递
private int tp;// 总页数, 计算
// 其他的提供 get/set 方法
// 但 tp 只提供 get 方法
public int getTp(){
tp=tr/ps;
return tr%ps==0?tp:tp+1;
}
public List<T> getBeanList() {return beanList;
}
public void setBeanList(List<T> beanList) {this.beanList = beanList;
}
public int getTr() {return tr;
}
public void setTr(int tr) {this.tr = tr;
}
public int getPc() {return pc;
}
public void setPc(int pc) {this.pc = pc;
}
public int getPs() {return ps;
}
public void setPs(int ps) {this.ps = ps;
}
}
index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<jsp:forward page="/frame.jsp" />
frame.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title> 主页 </title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<frameset rows="20%,*">
<frame src="<c:url value='/top.jsp'/>" name="top"/>
<frame src="<c:url value='/welcome.jsp'/>" name="main"/>
</frameset>
</html>
top.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<!-- 它的作用是为本页面所有的表单和超链接指定显示内容的框架！-->
<base target="main">
<title>My JSP 'top.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body style="text-align: center;">
<a href="<c:url value='/CustomerServlet'/>"> 查询客户 </a>
</body>
</html>
welcome.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>My JSP 'welcome.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h1 align="center"> 欢迎登录本系统 </h1>
</body>
</html>
list.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title> 客户列表 </title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
</head>
<body>
<h3 align="center"> 客户列表 </h3>
<table border="1" width="70%" align="center">
<tr>
<th> 客户姓名 </th>
<th> 性别 </th>
<th> 生日 </th>
<th> 手机 </th>
<th> 邮箱 </th>
<th> 描述 </th>
<th> 操作 </th>
</tr>
<c:forEach items="${pb.beanList}" var="cstm">
<tr>
<td>${cstm.cname}</td>
<td>${cstm.gender}</td>
<td>${cstm.birthday}</td>
<td>${cstm.cellphone}</td>
<td>${cstm.email}</td>
<td>${cstm.description}</td>
<td>
<a href="#"> 编辑 </a>
<a href="#"> 删除 </a>
</td>
</tr>
</c:forEach>
</table>
</br>
<!-- 给出分页相关的链接 -->
<center>
<a href='<c:url value="/CustomerServlet"/>'> 首页 </a>
<a href='<c:url value="/CustomerServlet?pc=${pb.pc-1}"/>'> 上一页 </a>
<a href='<c:url value="/CustomerServlet?pc=${pb.pc+1}"/>'> 下一页 </a>
<a href='<c:url value="/CustomerServlet?pc=${pb.tp}"/>'> 尾页 </a>
</center>
</body>
</html>
CustomerServlet.java
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class CustomerServlet
*/
public class CustomerServlet extends HttpServlet {private static final long serialVersionUID = 1L;
CustomerDao customerDao = new CustomerDao();
/**
* @see HttpServlet#HttpServlet()
*/
public CustomerServlet() {super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {/*
* 1、获取页面传递的 pc
* 2、给定 ps 的值
* 3、使用 pc 和 ps 调用 service 方法，得到 PageBean, 保存到 request 域
* 4、转发到 list.jsp
* */
/*
* 1. 得到 pc
* 如果 pc 参数不存在，说明 pc=1
* 如果 pc 参数存在，需要转换成 int 类型即可
* */
int pc = getPc(request);
int ps = 10;
PageBean pb = customerDao.findAll(pc,ps);
request.setAttribute("pb", pb);
request.getRequestDispatcher("/list.jsp").forward(request, response);
}
public int getPc(HttpServletRequest request) {String value = request.getParameter("pc");
if(value==null || value.trim().isEmpty()) {return 1;
}
return Integer.parseInt(value);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// TODO Auto-generated method stub
doGet(request, response);
}
}
CustomerDao.java
import java.sql.SQLException;
import java.util.List;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class CustomerDao {private QueryRunner qr = new QueryRunner(new ComboPooledDataSource());
/**
* 添加客户
*
* @param c
*/
public void add(Customer c) {try {String sql = "insert into t_customer values(?,?,?,?,?,?,?)";
Object[] params = { c.getCid(), c.getCname(), c.getGender(),
c.getBirthday(), c.getCellphone(), c.getEmail(),
c.getDescription()};
qr.update(sql, params);
} catch(SQLException e) {throw new RuntimeException(e);
}
}
public PageBean findAll(int pc,int ps) {try {/*
* 创建 PageBean 对象 pb
* 设置 pb 的 pc 和 ps
* 得到 tr, 给 pb 设置 tr
* 得到 beanList，设置给 pb
* */
PageBean<Customer> pb = new PageBean<Customer>();
pb.setPc(pc);
pb.setPs(ps);
/*
* 得到 tr
* */
String sql = "select count(*) from t_customer";
Number num = (Number)qr.query(sql, new ScalarHandler());
int tr = num.intValue();
pb.setTr(tr);
/*
* 得到 beanList
* */
sql = "select * from t_customer limit ?,?";
List<Customer> beanList = qr.query(sql,
new BeanListHandler<Customer>(Customer.class),
(pc-1)*pb.getPs(),
pb.getPs());
pb.setBeanList(beanList);
return pb;
} catch(SQLException e) {throw new RuntimeException(e);
}
}
}
正文完
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