第83节:Java中的学生管理系统分页功能
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2022-04-04 20:27:30
第83节:Java中的学生管理系统分页功能 分页功能一般可以做成两种，一种是物理分页，另一种是逻辑分页。这两种功能是有各自的特点的，物理分页是查询的时候，对数据库进行访问，只是查一页数据就进行返回，其特点是对内存中数据量存储不大，只是缺点就是要对数据库不断的进行访问；而对逻辑分页来说，就有所不同，它 ......
第83节:java中的学生管理系统分页功能
分页功能一般可以做成两种，一种是物理分页，另一种是逻辑分页。这两种功能是有各自的特点的，物理分页是查询的时候，对数据库进行访问，只是查一页数据就进行返回，其特点是对内存中数据量存储不大，只是缺点就是要对数据库不断的进行访问；而对逻辑分页来说，就有所不同，它是一下子就把所有的数据全部查询出来，然后放入到内存中，访问速度快，缺点就是对内存空间不足，数据量过大。
select * from stu limit 5;
// offset 偏移前面的多少条，offset 1 跳过前面的一条 select * from stu limit 5 offset 5;
select * from stu limit 5 , 5;
select * from stu limit 5 , 2;
select * from stu limit 2 , 5;
写分页的dao模式
// index.jsp <h3><a href="studentlistpageservlet?currentpage=1">分页显示所有学生</a></h3>
// studentlistpageservlet
//1. 获取需要显示的页码数
int currentpage =integer.parseint( request.getparameter("currentpage"));
// studentdao // 接口中定义的成员都是常量 // 一页显示多少条记录 int page_size = 5; // 分页dao,查询当页的学生数据 list<student> findstudentbypage(int currentpage) throws sqlexception;
// studentdaoimpl
@override
public list<student> findstudentbypage(int currentpage) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
// 第一个问号，一页返回多少条记录，第二个问号，跳过前面的多少条记录
//5 0 --- 第一页 (1-1)*5
//5 5 --- 第二页 (2-1)*5
//5 10 --- 第三页
return runner.query("select * from stu limit ? offset ?", new beanlisthandler<student>(student.class),page_size , (currentpage-1)*page_size);
}
业务逻辑
select count(*) from stu;
业务逻辑
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.pagebean;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* 这是用于分页显示学生列表的servlet
*/
public class studentlistpageservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
//1. 获取需要显示的页码数
int currentpage =integer.parseint( request.getparameter("currentpage"));
//2. 根据指定的页数，去获取该页的数据回来
//list<student> --- list.jsp
studentservice service = new studentserviceimpl();
pagebean pagebean= service.findstudentbypage(currentpage);
request.setattribute("pagebean", pagebean);
//3. 跳转界面。
request.getrequestdispatcher("list_page.jsp").forward(request, response);
} catch (sqlexception e) {
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
// todo auto-generated method stub
doget(request, response);
}
}
去业务逻辑去找
package com.dashucoding.service;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.domain.pagebean;
import com.dashucoding.domain.student;
/*
* 这是学生的业务处理规范
* */
public interface studentservice {
// 分页dao,查询当页的学生数据
// 分页的很多小逻辑业务 可以做到service里面
// 业务做到service里面，做的就是bean了，当前页，总页数，显示条数， 总记录数
// 返回的是一个bean了
// 返回的是pagebean里面的所有数据了
pagebean findstudentbypage(int currentpage) throws sqlexception;
// 根据姓名或性别，查询
list<student> searchstudent(string sname, string sgender) throws sqlexception;
/*
* 查询所有学生 list<student>
*/
list<student> findall() throws sqlexception;
void insert(student student) throws sqlexception;
// sid根据id删除学生
void delete(int sid) throws sqlexception;
// 根据id查询单个学生对象
student findstudentbyid(int sid) throws sqlexception;
// 更新学生信息
void update(student student) throws sqlexception;
}
package com.dashucoding.service.impl;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.dao.studentdao;
import com.dashucoding.dao.impl.studentdaoimpl;
import com.dashucoding.domain.pagebean;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
/*
* 这是学生业务实现
* */
public class studentserviceimpl implements studentservice {
@override
public list<student> findall() throws sqlexception {
studentdao dao = new studentdaoimpl();
return dao.findall();
}
@override
public void insert(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.insert(student);
}
@override
public void delete(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.delete(sid);
}
@override
public student findstudentbyid(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.findstudentbyid(sid);
}
@override
public void update(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.update(student);
}
@override
public list<student> searchstudent(string sname, string sgender) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.searchstudent(sname, sgender);
}
@override
public pagebean findstudentbypage(int currentpage) throws sqlexception {
// todo auto-generated method stub
// 封装分页的该页的数据
pagebean<student> pagebean = new pagebean<student>();
int pagesize = studentdao.page_size;
// 设置当前页
pagebean.setcurrentpage(currentpage);
// 每条记录
pagebean.setpagesize(pagesize);
studentdao dao = new studentdaoimpl();
list<student> list = dao.findstudentbypage(currentpage);
pagebean.setlist(list);
// 总记录数，总页数
int count = dao.findcount();
pagebean.settotalsize(count);
// 总页数
pagebean.settotalpage(count % pagesize == 0 ? count / pagesize : (count / pagesize) + 1);
return null;
}
}
// 封装的数据
package com.dashucoding.domain;
import java.util.list;
// 一个用于封装了分页的数据
// 有： 当前学生集合数据，总的记录数，总的页数，当前页，每页的显示记录数
public class pagebean<t> {
private int currentpage; // 当前页
private int totalpage;// 总页数
private int pagesize;// 每页的记录数，每页要显示多少记录
private int totalsize; // 总的记录数
private list<t> list; // 当前页的学生集合
public int getcurrentpage() {
return currentpage;
}
public void setcurrentpage(int currentpage) {
this.currentpage = currentpage;
}
public int gettotalpage() {
return totalpage;
}
public void settotalpage(int totalpage) {
this.totalpage = totalpage;
}
public int getpagesize() {
return pagesize;
}
public void setpagesize(int pagesize) {
this.pagesize = pagesize;
}
public int gettotalsize() {
return totalsize;
}
public void settotalsize(int totalsize) {
this.totalsize = totalsize;
}
public list<t> getlist() {
return list;
}
public void setlist(list<t> list) {
this.list = list;
}
}
最后就靠显示页面逻辑
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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>学生列表页面</title>
<script type="text/javascript">
function dodelete(sid) {
/* 如果这里弹出的对话框，用户点击的是确定，就马上去请求servlet。
如何知道用户点击的是确定。
如何在js的方法中请求servlet。 */
var flag = confirm("是否确定删除?");
if(flag){
//表明点了确定。 访问servlet。 在当前标签页上打开 超链接，
//window.location.href="deleteservlet?sid="+sid;
location.href="deleteservlet?sid="+sid;
}
}
</script>
</head>
<body>
<form action="searchstudentservlet" method="post">
<table border="1" width="700">
<tr >
<td colspan="8">
按姓名查询:<input type="text" name="sname"/>
按性别查询:<select name="sgender">
<option value="">--请选择--
<option value="男">男
<option value="女">女
</select>
<input type="submit" value="查询">
<a href="add.jsp">添加</a>
</td>
</tr>
<tr align="center">
<td>编号</td>
<td>姓名</td>
<td>性别</td>
<td>电话</td>
<td>生日</td>
<td>爱好</td>
<td>简介</td>
<td>操作</td>
</tr>
<c:foreach items="${pagebean.list }" var="stu">
<tr align="center">
<td>${stu.sid }</td>
<td>${stu.sname }</td>
<td>${stu.gender }</td>
<td>${stu.phone }</td>
<td>${stu.birthday }</td>
<td>${stu.hobby }</td>
<td>${stu.info }</td>
<td><a href="editservlet?sid=${stu.sid }">更新</a> <a href="#" onclick="dodelete(${stu.sid})">删除</a></td>
</tr>
</c:foreach>
<tr>
<td colspan="8">
第 ${pagebean.currentpage } / ${pagebean.totalpage }
每页显示${pagebean.pagesize }条
总的记录数${pagebean.totalsize }
<c:if test="${pagebean.currentpage !=1 }">
<a href="studentlistpageservlet?currentpage=1">首页</a>
| <a href="studentlistpageservlet?currentpage=${pagebean.currentpage-1 }">上一页</a>
</c:if>
<c:foreach begin="1" end="${pagebean.totalpage }" var="i">
<c:if test="${pagebean.currentpage == i }">
${i }
</c:if>
<c:if test="${pagebean.currentpage != i }">
<a href="studentlistpageservlet?currentpage=${i }">${i }</a>
</c:if>
</c:foreach>
<c:if test="${pagebean.currentpage !=pagebean.totalpage }">
<a href="studentlistpageservlet?currentpage=${pagebean.currentpage+1 }">下一页</a> |
<a href="studentlistpageservlet?currentpage=${pagebean.totalpage }">尾页</a>
</c:if>
</td>
</tr>
</table>
</form>
</body>
</html>
我的源码
package com.dashucoding.dao;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.domain.student;
/*
* 这是针对学生表的数据访问
*
* */
public interface studentdao {
// 接口中定义的成员都是常量
// 一页显示多少条记录
int page_size = 5;
// 分页dao,查询当页的学生数据
list<student> findstudentbypage(int currentpage) throws sqlexception;
// 根据姓名或性别，查询
list<student> searchstudent(string sname, string sgender) throws sqlexception;
/*
* 查询所有学生 list<student>
*/
list<student> findall() throws sqlexception;
void insert(student student) throws sqlexception;
// sid根据id删除学生
void delete(int sid) throws sqlexception;
// 根据id查询单个学生对象
student findstudentbyid(int sid) throws sqlexception;
// 更新学生信息
void update(student student) throws sqlexception;
// 查询总的学生记录数
int findcount() throws sqlexception;
}
package com.dashucoding.dao.impl;
import java.sql.connection;
import java.sql.sqlexception;
import java.util.arraylist;
import java.util.list;
import org.apache.commons.dbutils.queryrunner;
import org.apache.commons.dbutils.handlers.beanhandler;
import org.apache.commons.dbutils.handlers.beanlisthandler;
import org.apache.commons.dbutils.handlers.scalarhandler;
import com.dashucoding.dao.studentdao;
import com.dashucoding.domain.student;
import com.dashucoding.util.jdbcutil02;
import com.dashucoding.util.textutils;
/*
*这是studentdao的实现,针对前面定义的规范,做出具体的实现
* */
public class studentdaoimpl implements studentdao {
/*
* 查询所有学生
*/
@override
public list<student> findall() throws sqlexception {
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
return runner.query("select * from stu", new beanlisthandler<student>(student.class));
}
@override
public void insert(student student) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
runner.update("insert into stu values(null, ?,?,?,?,?,?)",
student.getsname(),
student.getgender(),
student.getphone(),
student.getbirthday(),
student.gethobby(),
student.getinfo()
);
}
@override
public void delete(int sid) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
runner.update("delete from stu where sid=?", sid);
}
@override
public student findstudentbyid(int sid) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
return runner.query("select * from stu where sid = ?", new beanhandler<student>(student.class), sid);
}
@override
public void update(student student) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
runner.update("update stu set sname=?, gender=?, phone=?, birthday=?, hobby=?, info=? where sid=?",
student.getsname(),
student.getgender(),
student.getphone(),
student.getbirthday(),
student.gethobby(),
student.getinfo(),
student.getsid());
}
// 模糊查询
@override
public list<student> searchstudent(string sname, string sgender) throws sqlexception {
// todo auto-generated method stub
/*system.out.println(sname + sgender);*/
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
/*
* string sql = "select * from stu where sname=? or sgender=?";
* select * from stu where sname like ?;
* select * from stu where gender = ?;
* select * from stu where sname like ? and gender = ?;
* 如果两个都没有就查询所有
* sql = "select * from stu"
* if(姓名){
* sql = sql + "where sname like ?";
* }
* if(性别){
* sql = sql + "where gender = ?";
* }
*
* string sql = "select * from stu where 1=1";
* if(姓名){
* sql = sql + " and sname like ? ";
* }
* if(性别){
* sql = sql + " and gender = ? ";
* }
* */
string sql = "select * from stu where 1=1";
list<string> list = new arraylist<string>();
if(!textutils.isempty(sname)) {
sql = sql + " and sname like ? ";
list.add("%"+sname+"%");
}
if(!textutils.isempty(sgender)) {
sql = sql + " and gender = ? ";
list.add(sgender);
}
/*list.toarray()*/
return runner.query(sql, new beanlisthandler<student>(student.class),list.toarray());
}
@override
public list<student> findstudentbypage(int currentpage) throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
// 第一个问号，一页返回多少条记录，第二个问号，跳过前面的多少条记录
//5 0 --- 第一页 (1-1)*5
//5 5 --- 第二页 (2-1)*5
//5 10 --- 第三页
return runner.query("select * from stu limit ? offset ?", new beanlisthandler<student>(student.class),page_size , (currentpage-1)*page_size);
}
// 查询总的记录数
@override
public int findcount() throws sqlexception {
// todo auto-generated method stub
queryrunner runner = new queryrunner(jdbcutil02.getdatasource());
// 用于处理平均值，总的个数
long result = (long) runner.query("select count(*) from stu", new scalarhandler());
return result.intvalue();
}
}
package com.dashucoding.domain;
import java.util.list;
// 一个用于封装了分页的数据
// 有： 当前学生集合数据，总的记录数，总的页数，当前页，每页的显示记录数
public class pagebean<t> {
private int currentpage; // 当前页
private int totalpage;// 总页数
private int pagesize;// 每页的记录数，每页要显示多少记录
private int totalsize; // 总的记录数
private list<t> list; // 当前页的学生集合
public int getcurrentpage() {
return currentpage;
}
public void setcurrentpage(int currentpage) {
this.currentpage = currentpage;
}
public int gettotalpage() {
return totalpage;
}
public void settotalpage(int totalpage) {
this.totalpage = totalpage;
}
public int getpagesize() {
return pagesize;
}
public void setpagesize(int pagesize) {
this.pagesize = pagesize;
}
public int gettotalsize() {
return totalsize;
}
public void settotalsize(int totalsize) {
this.totalsize = totalsize;
}
public list<t> getlist() {
return list;
}
public void setlist(list<t> list) {
this.list = list;
}
}
package com.dashucoding.domain;
import java.util.date;
/*
* 这是学生封装的对象bean
*
* */
public class student {
private int sid;
private string sname;
private string gender;
private string phone;
private string hobby;
private string info;
private date birthday;
public student() {
super();
// todo auto-generated constructor stub
}
public student(int sid, string sname, string gender, string phone, string hobby, string info, date birthday) {
super();
this.sid = sid;
this.sname = sname;
this.gender = gender;
this.phone = phone;
this.hobby = hobby;
this.info = info;
this.birthday = birthday;
}
public student(string sname, string gender, string phone, string hobby, string info, date birthday) {
super();
this.sname = sname;
this.gender = gender;
this.phone = phone;
this.hobby = hobby;
this.info = info;
this.birthday = birthday;
}
public int getsid() {
return sid;
}
public void setsid(int sid) {
this.sid = sid;
}
public string getsname() {
return sname;
}
public void setsname(string sname) {
this.sname = sname;
}
public string getgender() {
return gender;
}
public void setgender(string gender) {
this.gender = gender;
}
public string getphone() {
return phone;
}
public void setphone(string phone) {
this.phone = phone;
}
public string gethobby() {
return hobby;
}
public void sethobby(string hobby) {
this.hobby = hobby;
}
public string getinfo() {
return info;
}
public void setinfo(string info) {
this.info = info;
}
public date getbirthday() {
return birthday;
}
public void setbirthday(date birthday) {
this.birthday = birthday;
}
@override
public string tostring() {
return "student [sid=" + sid + ", sname=" + sname + ", gender=" + gender + ", phone=" + phone + ", hobby="
+ hobby + ", info=" + info + ", birthday=" + birthday + "]";
}
}
package com.dashucoding.service;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.domain.pagebean;
import com.dashucoding.domain.student;
/*
* 这是学生的业务处理规范
* */
public interface studentservice {
// 分页dao,查询当页的学生数据
// 分页的很多小逻辑业务 可以做到service里面
// 业务做到service里面，做的就是bean了，当前页，总页数，显示条数， 总记录数
// 返回的是一个bean了
// 返回的是pagebean里面的所有数据了
pagebean findstudentbypage(int currentpage) throws sqlexception;
// 根据姓名或性别，查询
list<student> searchstudent(string sname, string sgender) throws sqlexception;
/*
* 查询所有学生 list<student>
*/
list<student> findall() throws sqlexception;
void insert(student student) throws sqlexception;
// sid根据id删除学生
void delete(int sid) throws sqlexception;
// 根据id查询单个学生对象
student findstudentbyid(int sid) throws sqlexception;
// 更新学生信息
void update(student student) throws sqlexception;
}
package com.dashucoding.service.impl;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.dao.studentdao;
import com.dashucoding.dao.impl.studentdaoimpl;
import com.dashucoding.domain.pagebean;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
/*
* 这是学生业务实现
* */
public class studentserviceimpl implements studentservice {
@override
public list<student> findall() throws sqlexception {
studentdao dao = new studentdaoimpl();
return dao.findall();
}
@override
public void insert(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.insert(student);
}
@override
public void delete(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.delete(sid);
}
@override
public student findstudentbyid(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.findstudentbyid(sid);
}
@override
public void update(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.update(student);
}
@override
public list<student> searchstudent(string sname, string sgender) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.searchstudent(sname, sgender);
}
@override
public pagebean findstudentbypage(int currentpage) throws sqlexception {
// todo auto-generated method stub
// 封装分页的该页的数据
pagebean<student> pagebean = new pagebean<student>();
int pagesize = studentdao.page_size;
// 设置当前页
pagebean.setcurrentpage(currentpage);
// 每条记录
pagebean.setpagesize(pagesize);
studentdao dao = new studentdaoimpl();
list<student> list = dao.findstudentbypage(currentpage);
pagebean.setlist(list);
// 总记录数，总页数
int count = dao.findcount();
pagebean.settotalsize(count);
// 总页数
pagebean.settotalpage(count % pagesize == 0 ? count / pagesize : (count / pagesize) + 1);
return null;
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.text.simpledateformat;
import java.util.arrays;
import java.util.date;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* 用于处理学生的添加请求
*/
public class addservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
request.setcharacterencoding("utf-8");
try {
// 1. 获取客户端提交上来的数据
string sname = request.getparameter("sname");
string gender = request.getparameter("gender");
string phone = request.getparameter("phone");
string birthday = request.getparameter("birthday");
string info = request.getparameter("info");
// string hobby = request.getparameter("hobby");//hobby : 游泳，写字， 足球。
string[] h = request.getparametervalues("hobby");
string hobby = arrays.tostring(h);
hobby = hobby.substring(1, hobby.length() - 1);
// 2. 添加到数据库
// string -- date
date date = new simpledateformat("yyyy-mm-dd").parse(birthday);
student student = new student(sname, gender, phone, hobby, info, date);
studentservice service = new studentserviceimpl();
service.insert(student);
// 3. 跳转到列表页
request.getrequestdispatcher("studentlistservlet").forward(request, response);
} catch (exception e) {
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
doget(request, response);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* 用于处理删除学生
*/
public class deleteservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
try {
int sid = integer.parseint(request.getparameter("sid"));
// system.out.println("sid="+sid);
// 执行删除
studentservice service = new studentserviceimpl();
service.delete(sid);
// 跳转到列表页
request.getrequestdispatcher("studentlistservlet").forward(request, response);
} catch (sqlexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
doget(request, response);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* 处理单个学生的更新，查询学生的信息，跳转到更新的页面
*/
public class editservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
try {
// 接收id
int sid = integer.parseint(request.getparameter("sid"));
// 查询学生数据
studentservice service = new studentserviceimpl();
student stu = service.findstudentbyid(sid);
// 显示数据
// 存储数据
request.setattribute("stu", stu);
// 跳转
request.getrequestdispatcher("edit.jsp").forward(request, response);
} catch (sqlexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
/**
* @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);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import java.util.list;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* servlet implementation class searchstudentservlet
*/
public class searchstudentservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
request.setcharacterencoding("utf-8");
try {
// 取到了要查询的关键数据
string sname = request.getparameter("sname");
string sgender = request.getparameter("sgender");
// 找service查询
studentservice service = new studentserviceimpl();
list<student> list = service.searchstudent(sname, sgender);
/*for(student student : list) {
system.out.println("stu=" + student);
}*/
request.setattribute("list", list);
// 跳转界面
request.getrequestdispatcher("list.jsp").forward(request, response);
} catch (sqlexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
// todo auto-generated method stub
doget(request, response);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.pagebean;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* 这是用于分页显示学生列表的servlet
*/
public class studentlistpageservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
//1. 获取需要显示的页码数
int currentpage =integer.parseint( request.getparameter("currentpage"));
//2. 根据指定的页数，去获取该页的数据回来
//list<student> --- list.jsp
studentservice service = new studentserviceimpl();
pagebean pagebean= service.findstudentbypage(currentpage);
request.setattribute("pagebean", pagebean);
//3. 跳转界面。
request.getrequestdispatcher("list_page.jsp").forward(request, response);
} catch (sqlexception e) {
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
// todo auto-generated method stub
doget(request, response);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.sql.sqlexception;
import java.util.list;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.dao.studentdao;
import com.dashucoding.dao.impl.studentdaoimpl;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
public class studentlistservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
// 查询所有的学生
studentservice service = new studentserviceimpl();
list<student> list = service.findall();
// 把数据存储到作用域中
request.setattribute("list", list);
// 跳转页面
request.getrequestdispatcher("list.jsp").forward(request,response);
} catch (sqlexception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
doget(request, response);
}
}
package com.dashucoding.servlet;
import java.io.ioexception;
import java.text.simpledateformat;
import java.util.arrays;
import java.util.date;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
import com.dashucoding.service.impl.studentserviceimpl;
/**
* servlet implementation class updateservlet
*/
public class updateservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
request.setcharacterencoding("utf-8");
try {
// 1. 获取客户端提交上来的数据
int sid = integer.parseint(request.getparameter("sid"));
string sname = request.getparameter("sname");
string gender = request.getparameter("gender");
string phone = request.getparameter("phone");
string birthday = request.getparameter("birthday");
string info = request.getparameter("info");
// string hobby = request.getparameter("hobby");
string[] h = request.getparametervalues("hobby");
string hobby = arrays.tostring(h);
hobby = hobby.substring(1, hobby.length() - 1);
// 2. 添加到数据库
date date = new simpledateformat("yyyy-mm-dd").parse(birthday);
student student = new student(sid, sname, gender, phone, hobby, info, date);
// 2. 更新数据库数据
studentservice service = new studentserviceimpl();
service.update(student);
// 3. 跳转界面
request.getrequestdispatcher("studentlistservlet").forward(request, response);
} catch (exception e) {
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response)
throws servletexception, ioexception {
// todo auto-generated method stub
doget(request, response);
}
}
package com.dashucoding.util;
import java.io.fileinputstream;
import java.io.inputstream;
import java.sql.connection;
import java.sql.drivermanager;
import java.sql.resultset;
import java.sql.sqlexception;
import java.sql.statement;
import java.util.properties;
import javax.sql.datasource;
import com.mchange.v2.c3p0.combopooleddatasource;
public class jdbcutil02 {
static combopooleddatasource datasource = null;
static {
datasource = new combopooleddatasource();
}
public static datasource getdatasource() {
return datasource;
}
/**
* 获取连接对象
* @return
* @throws sqlexception
*/
public static connection getconn() throws sqlexception{
return datasource.getconnection();
}
/**
* 释放资源
* @param conn
* @param st
* @param rs
*/
public static void release(connection conn , statement st , resultset rs){
closers(rs);
closest(st);
closeconn(conn);
}
public static void release(connection conn , statement st){
closest(st);
closeconn(conn);
}
private static void closers(resultset rs){
try {
if(rs != null){
rs.close();
}
} catch (sqlexception e) {
e.printstacktrace();
}finally{
rs = null;
}
}
private static void closest(statement st){
try {
if(st != null){
st.close();
}
} catch (sqlexception e) {
e.printstacktrace();
}finally{
st = null;
}
}
private static void closeconn(connection conn){
try {
if(conn != null){
conn.close();
}
} catch (sqlexception e) {
e.printstacktrace();
}finally{
conn = null;
}
}
}
package com.dashucoding.util;
public class textutils {
/**
* 判断某一个字符串是否为空。
*
* @param s
* @return
*/
public static boolean isempty(charsequence s) {
return s == null || s.length() == 0;
}
}
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>添加学生页面</title>
</head>
<body>
<form method="post" action="addservlet">
<table border="1" width="600">
<tr>
<td>姓名</td>
<td><input type="text" name="sname"></td>
</tr>
<tr>
<td>性别</td>
<td><input type="radio" name="gender" value="男">男 <input
type="radio" name="gender" value="女">女</td>
</tr>
<tr>
<td>电话</td>
<td><input type="text" name="phone"></td>
</tr>
<tr>
<td>生日</td>
<td><input type="text" name="birthday"></td>
</tr>
<tr>
<td>爱好</td>
<td><input type="checkbox" name="hobby" value="游泳">游泳 <input
type="checkbox" name="hobby" value="篮球">篮球 <input
type="checkbox" name="hobby" value="足球">足球 <input
type="checkbox" name="hobby" value="看书">看书 <input
type="checkbox" name="hobby" value="写字">写字</td>
</tr>
<tr>
<td>简介</td>
<td><textarea name="info" rows="3" cols="20"></textarea></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="添加"></td>
</tr>
</table>
</form>
</body>
</html>
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<!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>更新学生页面</title>
</head>
<body>
<h3>更新学生页面</h3>
<form method="post" action="updateservlet">
<input type="hidden" name="sid" value="${stu.sid }">
<table border="1" width="600">
<tr>
<td>姓名</td>
<td><input type="text" name="sname" value="${stu.sname }"></td>
</tr>
<tr>
<td>性别</td>
<td>
<input type="radio" name="gender" value="男" <c:if test="${stu.gender == '男'}">checked</c:if>>男
<input type="radio" name="gender" value="女" <c:if test="${stu.gender == '女'}">checked</c:if>>女
</td>
</tr>
<tr>
<td>电话</td>
<td><input type="text" name="phone" value="${stu.phone }"></td>
</tr>
<tr>
<td>生日</td>
<td><input type="text" name="birthday" value="${stu.birthday }"></td>
</tr>
<tr>
<td>爱好</td>
<td>
<input type="checkbox" name="hobby" value="游泳" <c:if test="${fn:contains(stu.hobby,'游泳') }">checked</c:if>>游泳
<input type="checkbox" name="hobby" value="篮球" <c:if test="${fn:contains(stu.hobby,'篮球') }">checked</c:if>>篮球
<input type="checkbox" name="hobby" value="足球" <c:if test="${fn:contains(stu.hobby,'足球') }">checked</c:if>>足球
<input type="checkbox" name="hobby" value="看书" <c:if test="${fn:contains(stu.hobby,'看书') }">checked</c:if>>看书
<input type="checkbox" name="hobby" value="写字" <c:if test="${fn:contains(stu.hobby,'写字') }">checked</c:if>>写字
</td>
</tr>
<tr>
<td>简介</td>
<td><textarea name="info" rows="3" cols="20">${stu.info }</textarea></td>
</tr>
<tr>
<td colspan="2"> <input type="submit" value="更新"> </td>
</tr>
</table>
</form>
</body>
</html>
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>首页</title>
</head>
<body>
<h3><a href="studentlistservlet">显示所有学生列表</a></h3><br>
<h3><a href="studentlistpageservlet?currentpage=1">分页显示所有学生</a></h3>
</body>
</html>
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>学生列表页面</title>
<script type="text/javascript">
function dodelete(sid) {
// 弹出对话框，点击确定，请求servlet
var flag = confirm("是否确定删除?");
if(flag){
//访问servlet
//window.location.href="deleteservlet?sid="+sid;
location.href="deleteservlet?sid="+sid;
}
}
</script>
</head>
<body>
<form action="searchstudentservlet" method="post">
<table border="1" width="700">
<tr >
<td colspan="8">
按姓名查询:<input type="text" name="sname"/>
按性别查询:<select name="sgender">
<option value="">--请选择--
<option value="男">男
<option value="女">女
</select>
<input type="submit" value="查询">
<a href="add.jsp">添加</a>
</td>
</tr>
<tr align="center">
<td>编号</td>
<td>姓名</td>
<td>性别</td>
<td>电话</td>
<td>生日</td>
<td>爱好</td>
<td>简介</td>
<td>操作</td>
</tr>
<c:foreach items="${list }" var="stu">
<tr align="center">
<td>${stu.sid }</td>
<td>${stu.sname }</td>
<td>${stu.gender }</td>
<td>${stu.phone }</td>
<td>${stu.birthday }</td>
<td>${stu.hobby }</td>
<td>${stu.info }</td>
<td><a href="editservlet?sid=${stu.sid }">更新</a> <a href="#" onclick="dodelete(${stu.sid})">删除</a></td>
</tr>
</c:foreach>
</table>
</form>
</body>
</html>
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>学生列表页面</title>
<script type="text/javascript">
function dodelete(sid) {
// 弹出对话框，点击确定，请求servlet
var flag = confirm("是否确定删除?");
if(flag){
//访问servlet
//window.location.href="deleteservlet?sid="+sid;
location.href="deleteservlet?sid="+sid;
}
}
</script>
</head>
<body>
<form action="searchstudentservlet" method="post">
<table border="1" width="700">
<tr>
<td colspan="8">按姓名查询:<input type="text" name="sname" />
按性别查询:<select name="sgender">
<option value="">--请选择--
<option value="男">男
<option value="女">女
</select> <input type="submit" value="查询">
<a href="add.jsp">添加</a>
</td>
</tr>
<tr align="center">
<td>编号</td>
<td>姓名</td>
<td>性别</td>
<td>电话</td>
<td>生日</td>
<td>爱好</td>
<td>简介</td>
<td>操作</td>
</tr>
<c:foreach items="${pagebean.list }" var="stu">
<tr align="center">
<td>${stu.sid }</td>
<td>${stu.sname }</td>
<td>${stu.gender }</td>
<td>${stu.phone }</td>
<td>${stu.birthday }</td>
<td>${stu.hobby }</td>
<td>${stu.info }</td>
<td><a href="editservlet?sid=${stu.sid }">更新</a> <a href="#"
onclick="dodelete(${stu.sid})">删除</a></td>
</tr>
</c:foreach>
<tr>
<td colspan="8">第 ${pagebean.currentpage } /
${pagebean.totalpage } 每页显示${pagebean.pagesize }条
总的记录数${pagebean.totalsize } <c:if
test="${pagebean.currentpage !=1 }">
<a href="studentlistpageservlet?currentpage=1">首页</a>
| <a
href="studentlistpageservlet?currentpage=${pagebean.currentpage-1 }">上一页</a>
</c:if> <c:foreach begin="1" end="${pagebean.totalpage }" var="i">
<c:if test="${pagebean.currentpage == i }">
${i }
</c:if>
<c:if test="${pagebean.currentpage != i }">
<a href="studentlistpageservlet?currentpage=${i }">${i }</a>
</c:if>
</c:foreach> <c:if test="${pagebean.currentpage !=pagebean.totalpage }">
<a
href="studentlistpageservlet?currentpage=${pagebean.currentpage+1 }">下一页</a> |
<a
href="studentlistpageservlet?currentpage=${pagebean.totalpage }">尾页</a>
</c:if>
</td>
</tr>
</table>
</form>
</body>
</html>
package com.dashucoding.service.impl;
import java.sql.sqlexception;
import java.util.list;
import com.dashucoding.dao.studentdao;
import com.dashucoding.dao.impl.studentdaoimpl;
import com.dashucoding.domain.pagebean;
import com.dashucoding.domain.student;
import com.dashucoding.service.studentservice;
/*
* 这是学生业务实现
* */
public class studentserviceimpl implements studentservice {
@override
public list<student> findall() throws sqlexception {
studentdao dao = new studentdaoimpl();
return dao.findall();
}
@override
public void insert(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.insert(student);
}
@override
public void delete(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.delete(sid);
}
@override
public student findstudentbyid(int sid) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.findstudentbyid(sid);
}
@override
public void update(student student) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
dao.update(student);
}
@override
public list<student> searchstudent(string sname, string sgender) throws sqlexception {
// todo auto-generated method stub
studentdao dao = new studentdaoimpl();
return dao.searchstudent(sname, sgender);
}
@override
public pagebean findstudentbypage(int currentpage) throws sqlexception {
// 封装分页的该页数据
pagebean<student> pagebean = new pagebean<student>();
int pagesize = studentdao.page_size;
pagebean.setcurrentpage(currentpage);
// 设置当前页
pagebean.setpagesize(pagesize);
// 设置每页显示多少记录
studentdao dao = new studentdaoimpl();
list<student> list = dao.findstudentbypage(currentpage);
pagebean.setlist(list);
// 设置这一页的学生数据
// 总的记录数， 总的页数。
int count = dao.findcount();
pagebean.settotalsize(count);
// 设置总的记录数
pagebean.settotalpage(count % pagesize == 0 ? count / pagesize : (count / pagesize) + 1); // 总页数
return pagebean;
}
}
结言
好了，欢迎在留言区留言，与大家分享你的经验和心得。
感谢你学习今天的内容，如果你觉得这篇文章对你有帮助的话，也欢迎把它分享给更多的朋友，感谢。
达叔小生：往后余生，唯独有你
you and me, we are family !
90后帅气小伙，良好的开发习惯；独立思考的能力；主动并且善于沟通
简书博客： 达叔小生
结语
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