Filter处理中文乱码

package 过滤器;import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;@WebFilter("/*")
public class MycourseCourseFilter implements Filter {public void destroy() {}public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {response.setContentType("text/html;charset=utf-8");chain.doFilter(request, response);}public void init(FilterConfig fConfig) throws ServletException {}}

数据库连接池

package 数据库连接池;import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;import javax.sql.DataSource;import org.apache.commons.dbcp.BasicDataSourceFactory;public class ConnectionUtils {private static DataSource dataSource = null;static {try {Properties properties = new Properties();InputStream inStream = ConnectionUtils.class.getClassLoader().getResourceAsStream("db.properties");properties.load(inStream);dataSource = BasicDataSourceFactory.createDataSource(properties);} catch (Exception e) {e.printStackTrace();}}public static DataSource getConnection() {return dataSource;}
}

课程信息javabean
course

package 图书信息javabean;import java.io.Serializable;public class Course implements Serializable {private Integer id;private String name;private String desc;private double price;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getDesc() {return desc;}public void setDesc(String desc) {this.desc = desc;}public double getPrice() {return price;}public void setPrice(double price) {this.price = price;}@Overridepublic String toString() {return "Book [id=" + id + ", name=" + name + ", desc=" + desc + ", price=" + price + "]";}}

mycourse

package 图书信息javabean;import java.io.Serializable;
import java.util.List;public class Mycourse implements Serializable {private Integer id;private Integer bookId;private Integer count;private Course book;public Course getBook() {return book;}public void setBook(Course book) {this.book = book;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Integer getBookId() {return bookId;}public void setBookId(Integer bookId) {this.bookId = bookId;}public Integer getCount() {return count;}public void setCount(Integer count) {this.count = count;}@Overridepublic String toString() {return "Bar [id=" + id + ", bookId=" + bookId + ", count=" + count + "]";}}

coursedao

package dao;import java.sql.SQLException;
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 图书信息javabean.Course;
import 数据库连接池.ConnectionUtils;public class CourseDao {public List<Course> findAll() {QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());String sql = "select *from book";System.out.println("=============================================");try {return runner.query(sql, new BeanListHandler<Course>(Course.class));} catch (SQLException e) {e.printStackTrace();return null;}}public Course findById(Integer id) {QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());String sql = "select *from book where id=?";System.out.println("=============================================");try {return runner.query(sql, new BeanHandler<Course>(Course.class), id);} catch (SQLException e) {e.printStackTrace();return null;}}
}

**`package dao;

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 图书信息javabean.Mycourse;
import 图书信息javabean.Course;
import 数据库连接池.ConnectionUtils;

public class MycourseDao {
public List findAll() {
QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());
String sql = “select * from car”;
try {
return runner.query(sql, new BeanListHandler(Mycourse.class));
} catch (SQLException e) {
e.printStackTrace();
return null;
}
}

public Integer saveCar(Mycourse bar) {QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());String sql = "insert into car(bookId, count)values(?, ?)";try {return runner.update(sql, bar.getBookId(), bar.getCount());} catch (SQLException e) {e.printStackTrace();return 0;}
}public Integer updateCar(Mycourse bar) {QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());String sql = "update car set bookId=?, count=? where id=?";try {return runner.update(sql, bar.getBookId(), bar.getCount(), bar.getId());} catch (SQLException e) {e.printStackTrace();return 0;}
}public Mycourse findByBookId(Integer id) {QueryRunner runner = new QueryRunner(ConnectionUtils.getConnection());String sql = "select *from car where bookId=?";try {Mycourse bar = runner.query(sql, new BeanHandler<Mycourse>(Mycourse.class), id);return bar;} catch (SQLException e) {e.printStackTrace();return null;}
}

}
`**

servlet
CourseServlet

package Servlet;import java.io.IOException;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import dao.CourseDao;
import 图书信息javabean.Course;@WebServlet(value = "/CourseServlet")
public class CourseServlet extends HttpServlet {protected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {CourseDao bookDao = new CourseDao();List<Course> books = bookDao.findAll();
//		System.out.println(books);request.setAttribute("bookList", books);request.getRequestDispatcher("/WEB-INF/course.jsp").forward(request, response);}protected void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

DownloadServlet`

package Servlet;import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;
import java.nio.file.Files;
import java.nio.file.Paths;@WebServlet("/download")
public class DownloadServlet extends HttpServlet {protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 设置响应数据的 MIME 类型resp.setContentType("application/x-msdownload");// 获取文件名称String fileName = req.getParameter("fileName");// 判断浏览器是否是 IEString userAgent = req.getHeader("User-Agent");if (userAgent.contains("MSIE")) {// IE// 设置文件的名称resp.setHeader("Content-Disposition", "attachment; fileName="+ URLEncoder.encode(fileName, "UTF-8"));} else {// 非IEresp.setHeader("Content-Disposition", "attachment; fileName="+ new String(fileName.getBytes("UTF-8"), "ISO-8859-1"));}// 获取文件所在的路径String path = req.getServletContext().getRealPath("/WEB-INF/download");// 获取指定的文件对象File f = new File(path, fileName);ServletOutputStream out = resp.getOutputStream();// 将文件复制到输出流中，响应给浏览器Files.copy(Paths.get(f.getAbsolutePath()), out);}
}

MycourseServlet

package Servlet;import java.io.IOException;
import java.util.ArrayList;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import dao.MycourseDao;
import dao.CourseDao;
import 图书信息javabean.Mycourse;
import 图书信息javabean.Course;@WebServlet("/MycourseServlet")
public class MycourseServlet extends HttpServlet {protected void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {if (request.getParameter("id") == null) {this.showCar(request, response);return;}Integer para_id = Integer.parseInt(request.getParameter("id"));System.out.println(para_id);CourseDao bookDao = new CourseDao();Course hasBook = bookDao.findById(para_id);System.out.println(hasBook);if (hasBook == null) {request.getRequestDispatcher("/BookServlet").forward(request, response);} else {MycourseDao carDao = new MycourseDao();Mycourse car = carDao.findByBookId(para_id);if (car == null) {car = new Mycourse();car.setBookId(para_id);car.setCount(1);carDao.saveCar(car);} else {car.setCount(car.getCount() + 1);carDao.updateCar(car);}System.out.println(car);this.showCar(request, response);return;}}protected void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}private void showCar(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {CourseDao bookDao = new CourseDao();MycourseDao carDao = new MycourseDao();List<Mycourse> bars = carDao.findAll();System.out.println(bars);for (Mycourse b : bars) {Course book = bookDao.findById(b.getBookId());book.setPrice(book.getPrice() * b.getCount());b.setBook(book);}request.setAttribute("barList", bars);request.getRequestDispatcher("/WEB-INF/mycourse.jsp").forward(request, response);}
}

db.properties
注意密码（我的为空）

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/db
username=root
password=

course.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>课程管理模块</title>
</head>
<body style="text-align:center;"><h2>学生选课表</h2><table width="80%" border="3" align="center"><tr><td>课程代码</td><td>课程名称</td><td>课时</td><td>学生操作</td></tr><c:forEach items="${ bookList }" var="book"><tr><td>${ book.name }</td><td>${ book.desc }</td><td>${ book.price }</td><font color="green"><td><a href="MycourseServlet?id=${ book.id }"><font color="red">我要选课</font></a></td></font></tr></c:forEach></table>&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;<a href="MycourseServlet"><a href="MycourseServlet"><font color="green">点击查看已选课程</a></body>
</html>

mycourse.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>我的选课表</title>
</head>
<body style="text-align:center;"><h2>已选课程</h2><table width="80%" border="5" align="center"><tr><td>课程名</td><td>总课时</td><td>已选学生人数</td></tr><c:forEach items="${ barList }" var="car"><tr><td>${ car.book.name }</td><td>${ car.book.price }</td><td>${ car.count }</td></tr></c:forEach></table>&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;&emsp;<a href="CourseServlet"><font color="green">点击返回选课列表</a><a href="download.jsp"><font color="green">点击下载选课表</a>
</body>
</html>

download.jsp

<%@ 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>Insert title here</title>
</head>
<body><a href="download?fileName=test.png"}>点击下载课程表</a>
</body>
</html>

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>书城主界面</title>
</head>
<body>
//跳转到商品页面ShowServlet
<jsp:forward page="CourseServlet"></jsp:forward>
</body>
</html>