目录
- 一. 引言
- 二. 文件上传
- 三. 文件下载
- 四. EMS综合项目
- 4.1 项目需求
- 4.2 项目搭建
- 4.3 项目开发
- 4.3.1 Dbutils工具类
- 4.3.2 EmpManager实体类
- 4.3.3 Emp实体类
- 4.3.4 Page实体类
- 4.3.5 EmpManagerDao
- 4.3.6 EmpDao
- 4.3.7 EmpManagerDaoImpl
- 4.3.8 EmpDaoImpl
- 4.3.9 EmpManagerService
- 4.3.10 EmpService
- 4.3.11 EmpManagerServiceImpl
- 4.3.12 EmpServiceImpl
- 4.3.13 login.jsp
- 4.3.14 empList.jsp
- 4.3.15 addEmp.jsp
- 4.3.16 EmpManagerLoginController
- 4.3.17 CreateCodeController
- 4.3.18 ShowAllEmpController
- 4.3.19 AddEmpController
- 4.3.20 RemoveEmpController
- 4.3.21 ShowEmpController
- 4.3.22 UpdateEmpController
- 4.3.23 EncodingFilter
- 4.3.24 CheckFilter
- 五. Web开发总结
一. 引言
1.1 场景
- 在项目中, 文件的上传和下载是常见的功能, 很多程序或者软件中都经常使用到文件的上传和下载
- 邮箱中有附件的上传和下载
- OA办公系统中有附件材料的上传
二. 文件上传
2.1 概念
- 当用户在前端页面点击文件上传后, 用户上传的文件数据提交给服务器端, 实现保存
2.2 文件上传实现步骤
2.2.1 提交方式
- 提供form表单, method必须是post, 因为post请求无数据限制
<form method="post">
</form>
2.2.2 提交数据格式
- 表单的enctype属性值必须为multipart/form-data
- 以多段的形式进行拼接提交, 以二进制流的方式来处理表单数据, 会把指定的文件内容封装进请求参数中
<form enctype="multipart/form-data" method="post">
</form>
2.2.3 提供组件
- 提供file表单组件, 提供给用户上传文件
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>文件上传页面</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/upload" enctype="multipart/form-data" method="post">
<p>用户名:
<input type="text" name="username">
</p>
<p>密码:
<input type="file" name="file1">
</p>
<p>
<input type="submit" value="上传">
</p>
</form>
</body>
</html>
2.2.4 Controller编写
- 在Servlet 3.0 及其以上版本的容器中进行服务器端文件上传的编程, 是围绕着注解类型MultipartConfig 和 javax.servlet.http.Part 接口进行的, 处理已上传文件的Servlet必须以@MultipartConfig进行注解
package com.dz.servlet;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.File;
import java.io.IOException;
@WebServlet(name = "uploadController",value = "/upload")
@MultipartConfig(maxFileSize = 1024*1024*100,maxRequestSize = 1024*1024*200)
public class uploadController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//实现文件上传
//1. 设置乱码
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//2. 获取请求的数据
String username = request.getParameter("username");
Part part = request.getPart("file1");
//3. 获取上传文件的路径(将上传的文件存到此路径下) 真实路径
String uploadPath = request.getServletContext().getRealPath("/WEB-INF/upload");
File file = new File(uploadPath);
if (!file.exists()) {
file.mkdirs();//新建文件夹
}
//4. 文件上传
part.write(uploadPath+"\"+part.getSubmittedFileName());
//5. 响应客户端 上传成功
response.getWriter().println(part.getSubmittedFileName()+"上传成功!");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
2.3 文件上传细节注意
- 上述代码虽然可以成功将文件上传到服务器的指定目录当中, 但是文件上传功能有许多需要注意的小细节问题
2.3.1 安全问题
- 为保证服务器安全, 上传的文件应该放在外界无法直接访问的目录下, 比如放于WEB-INF目录下
String uploadPath = request.getServletContext().getRealPath("/WEB-INF/upload");
2.3.2 文件覆盖
- 当上传重名的文件时, 为防止文件覆盖的现象发生, 要为上传文件产生一个唯一的文件名
package com.dz.utils;
import java.util.UUID;
public class UploadUtils {
//使用UUID生成唯一标识码, 并拼接上图片的名称
public static String newFileName(String filename) {
return UUID.randomUUID().toString().replaceAll("-","") + "_" + filename;
}
}
//4. 文件上传
// 生成唯一文件名
//String oldName = part.getSubmittedFileName();
//String newName = UploadUtils.newFileName(oldName);
//part.write(uploadPath+"\"+newName);
2.3.3 散列存储
- 为防止一个目录下面出现太多文件, 要使用hash算法生成二级, 三级目录, 散列存储上传的文件
public class UploadUtils {
//使用UUID生成唯一标识码, 并拼接上图片的名称
public static String newFileName(String filename) {
return UUID.randomUUID().toString().replaceAll("-","") + "_" + filename;
}
//生成二三级目录,进行散列存储
public static String newFilePath(String basePath, String fileName) {
int hashcode = fileName.hashCode();
int path1 = hashcode & 15;//二级目录 与运算 0~15
int path2 = (hashcode>>4) & 15;//三级目录 与运算 0~15
String newPath = basePath + "\" + path1 + "\" + path2;//一二三级目录拼接在一起
File file = new File(newPath);//创建文件夹对象
if (!file.exists()) {//不存在则创建
file.mkdirs();
}
return newPath;//返回新路径
}
}
//4. 文件上传
// 生成唯一文件名
//String oldName = part.getSubmittedFileName();
//String newName = UploadUtils.newFileName(oldName);
//生成二级三级目录, 实现散列存储
//String newPath = UploadUtils.newFilePath(uploadPath, oldName);
//part.write(newPath+"\"+newName);
2.3.4 文件类型限制
- 要限制上传文件的类型, 在收到上传文件名时, 判断后缀名是否合法
//创建一个集合存放允许上传的文件类型(后缀名)
//判断集合中是否包含上传文件的后缀名
List<String> nameList = new ArrayList<>();
nameList.add(".png");
nameList.add(".jpg");
nameList.add(".jpeg");
String extName = oldName.substring(oldName.lastIndexOf("."));//从每个上传文件名中的最后出现点的位置开始截取, 也就是截取 后缀名(包括.)
if (!nameList.contains(extName)) {
response.getWriter().println(oldName + "的文件类型不支持上传!");
return;
}
2.4 多文件上传
package com.dz.servlet;
import com.dz.utils.UploadUtils;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
/**
* @belongsProject: FileUpload
* @belongsPackage: ${PACKAGE_NAME}
* @author: zheng
* @description: ${Description}
* @createTime: 2021-04-17 18:24
* @since v1.0.0
*/
@WebServlet(name = "MoreUploadController",value = "/moreUpload")
@MultipartConfig(maxFileSize = 1024*1024*100, maxRequestSize = 1024*1024*200)
public class MoreUploadController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//实现多文件上传
//1. 设置乱码
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//2. 获取上传文件的保存路径, 将上传的文件存放于WEB-INF目录下, 不允许外界直接访问, 保证上传文件的安全
String basePath = request.getServletContext().getRealPath("/WEB-INF/upload");
File file = new File(basePath);
if (!file.exists()) {
file.mkdirs();//WEB-INF下新建upload文件夹
}
//3. 获得表单提交的所有数据,放在集合里
Collection<Part> parts = request.getParts();
//4. 遍历集合
if (parts != null) {
for (Part part : parts) {
//4.1 获取上传文件的文件名
String fileName = part.getSubmittedFileName();
if (fileName != null) {//文件名不为空后我们认为是 文件数据
//二次判断(看文件名是否为空字符串),避免用户传入空数据
if (fileName.trim().equals("")) {
continue;
}
//4.1.1 调用上传工具类中的newFileName方法生成新的唯一文件名(使用UUID生成唯一标识码)
String newName = UploadUtils.newFileName(fileName);
//4.1.2 创建集合, 里面存放文件的后缀名,如果所上传文件的后缀名不在此集合内, 则不允许上传
List<String> fileNameList = new ArrayList<>();
fileNameList.add(".jpg");
fileNameList.add(".png");
fileNameList.add(".jpeg");
//截取文件后缀名(包括.) 从每个上传文件名中的最后出现点的位置开始截取
String extName = fileName.substring(fileName.lastIndexOf("."));
if (!fileNameList.contains(extName)) {
response.getWriter().println(fileName + "的文件类型不支持上传!");
return;
}
//4.1.3 获取分散后的路径,调用上传工具类中的newFilePath方法生成二级三级目录, 实现散列存储(文件名hashcode的与运算)
String newPath = UploadUtils.newFilePath(basePath,fileName);
//4.1.4 把新文件路径和新文件名进行拼接, 然后写入文件数据
part.write(newPath + "\" + newName);
//4.1.5 响应给客户端结果
response.getWriter().println(part.getSubmittedFileName()+"上传成功!");
}else{//没有获取到文件名则证明是 普通表单
//获取普通表单数据
String username = request.getParameter("username");
System.out.println(username);
}
}
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
三. 文件下载
3.1 概念
- 我们要将Web应用系统中的文件资源提供给用户进行下载, 首先我们要有一个页面列出上传文件目录下的所有文件, 当用户点击文件下载超链接时就进行下载操作
3.2 获取文件列表
3.2.1 DownLoadUtils
package com.dz.utils;
import java.io.File;
import java.util.HashMap;
public class DownLoadUtils {
public static void getFileList(File file, HashMap<String,String> fileMap) {
//获取当前文件对象下的所有内容(文件,文件夹)
File[] files = file.listFiles();
//如果数组不为空, 证明有文件或文件夹
if (files != null) {
//每次拿到文件对象(文件,文件夹)
for (File file1 : files) {
//如果是文件夹
if (file1.isDirectory()) {
//则递归调用getFileList方法
getFileList(file1,fileMap);
}else {
//获得文件名称
String fileName = file1.getName();
//获取第一个_的下标
int index = fileName.indexOf("_");
//获取源文件名称(去掉UUID_后的文件名)
String realName = fileName.substring(index + 1);
//UUID 键 源文件名 值
fileMap.put(fileName,realName);
}
}
}
}
}
3.2.2 FileListController
package com.dz.servlet;
import com.dz.utils.DownLoadUtils;
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 java.io.File;
import java.io.IOException;
import java.util.HashMap;
@WebServlet(name = "FileListController",value = "/fileList")
public class FileListController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1. 解决乱码
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//2. 获取文件列表
//集合,map key=UUID value=源文件名称
HashMap<String,String> fileMap = new HashMap<>();
String basePath = request.getServletContext().getRealPath("/WEB-INF/upload");
DownLoadUtils.getFileList(new File(basePath),fileMap);
//3. 转发 将fileMap存储到request作用域中并转发到fileList.jsp页面
request.setAttribute("fileMap",fileMap);
request.getRequestDispatcher("/fileList.jsp").forward(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
3.3 下载
3.3.1 fileList.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>文件下载页面</title>
</head>
<body>
<table>
<tr>
<th>文件名</th>
<th>操作</th>
</tr>
<c:forEach var="entry" items="${fileMap}" >
<tr>
<td>${entry.value}</td>
<td><a href="${pageContext.request.contextPath}/downLoad?filename=${entry.key}">下载</a></td>
</tr>
</c:forEach>
</table>
</body>
</html>
3.3.2 DownLoadController
package com.dz.servlet;
import com.dz.utils.UploadUtils;
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.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;
@WebServlet(name = "DownLoadController",value = "/downLoad")
public class DownLoadController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");//处理用户名的乱码
response.setContentType("text/html;charset=UTF-8");
String basePath = request.getServletContext().getRealPath("/WEB-INF/upload");
//1. 获取UUID 文件名
String uuidFilename = request.getParameter("filename");
//通过_拆分 UUID和源文件名称,_后是源文件名称
String filename = uuidFilename.split("_")[1];
//通过上传工具类, 使用源文件名称获得散列存储的路径, 就是要下载的路径
String downLoadPath = UploadUtils.newFilePath(basePath, filename);
//设置响应头, 告诉浏览器响应的文件类型和如何处理该文件, 附件下载
response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(filename,"UTF-8"));
//2. 使用流读取
FileInputStream fis = new FileInputStream(downLoadPath + "\" + uuidFilename);
ServletOutputStream sos = response.getOutputStream();
byte[] buffer = new byte[1024*1024*100];
int len = 0;
while ((len=fis.read(buffer)) != -1) {
sos.write(buffer,0,len);
}
//3. 关闭流
sos.close();
fis.close();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
四. EMS综合项目
4.1 项目需求
- 将提供好的HTML页面, 修改为JSP
- 实现管理员登陆功能, 并应用权限验证
- 对员工实现增删改查
- 查询员工使用分页查询, 并提供首页, 尾页, 上一页, 下一页
4.2 项目搭建
4.2.1 项目目录搭建
- com.dz.ems.utils 工具包
- com.dz.ems.entity 实例类
- com.dz.ems..dao 数据访问接口
- com.dz.ems.dao.impl 数据访问实现类
- com.dz.ems.service 业务逻辑接口
- com.dz.ems..service.impl 业务逻辑实现类
- com.dz.ems.controller 控制器
- com.dz.ems.filter 过滤器
4.2.2 项目资源引入
- 创建EMS项目, 在web的WEB-IF下创建lib目录并导入相关jar文件
- commons-dbutils-1.7.jar
- druid-1.1.5.jar
- jstl.jar
- mysql-connector-java-5.1.25-bin.jar
- standard.jar
- ValidateCode.jar
4.2.3 数据库创建
#创建ems数据库
CREATE DATABASE ems;
#使用ems数据库
USE ems;
#创建员工表
CREATE TABLE emp(
id INT PRIMARY KEY AUTO_INCREMENT,
NAME VARCHAR(20) NOT NULL,
salary DOUBLE NOT NULL,
age INT NOT NULL
)CHARSET=utf8;
#创建管理员表
CREATE TABLE empManager(
username VARCHAR(20) NOT NULL,
PASSWORD VARCHAR(20) NOT NULL
)CHARSET=utf8;
#请自行插入多条数据
INSERT INTO emp(NAME,salary,age) VALUES('DZ1',1000,18);
INSERT INTO empManager(username,PASSWORD) VALUES('admin','admin');
4.3.4 database.properties
#<!-- 连接设置 -->
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/ems?useUnicode=true&characterEncoding=UTF-8
username=root
password=root
#<!-- 初始化连接 -->
initialSize=10
#<!-- 最大连接数量 -->
maxActive=50
#<!-- 最小空闲连接 -->
minIdle=5
#<!-- 超时等待时间以毫秒为单位 60000毫秒/1000等于60秒 -->
maxWait=5000
4.3 项目开发
4.3.1 Dbutils工具类
public class DbUtils {
private static DruidDataSource ds;
private static final ThreadLocal<Connection> THREAD_LOCAL = new ThreadLocal<>();
static {
Properties properties = new Properties();
InputStream inputStream = DbUtils.class.getResourceAsStream("/database.properties");
try {
properties.load(inputStream);
ds = (DruidDataSource) DruidDataSourceFactory.createDataSource(properties);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
public static Connection getConnection(){
Connection conn = THREAD_LOCAL.get();
try {
if (conn == null) {
conn = ds.getConnection();
THREAD_LOCAL.set(conn);
}
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return conn;
}
public static void begin() {
Connection conn = null;
try {
conn = getConnection();
conn.setAutoCommit(false);
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
public static void commit() {
Connection conn = null;
try {
conn = getConnection();
conn.commit();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll(conn,null,null);
}
}
public static void rollback() {
Connection conn = null;
try {
conn = getConnection();
conn.rollback();
} catch (SQLException throwables) {
throwables.printStackTrace();
} finally {
closeAll(conn,null,null);
}
}
public static void closeAll(Connection conn, Statement statement, ResultSet resultSet) {
try {
if (resultSet != null) {
resultSet.close();
}
if (statement != null) {
statement.close();
}
if (conn != null) {
conn.close();
THREAD_LOCAL.remove();
}
} catch (SQLException throwables) {
throwables.printStackTrace();
}
}
}
4.3.2 EmpManager实体类
public class EmpManager {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public EmpManager(String username, String password) {
this.username = username;
this.password = password;
}
public EmpManager() {
}
}
4.3.3 Emp实体类
public class Emp {
private int id;
private String name;
private double salary;
private int age;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Emp(int id, String name, double salary, int age) {
this.id = id;
this.name = name;
this.salary = salary;
this.age = age;
}
public Emp(String name, double salary, int age) {
this.name = name;
this.salary = salary;
this.age = age;
}
public Emp() {
}
}
4.3.4 Page实体类
public class Page {
private Integer pageIndex;//页码
private Integer pageSize;//单页数据量
private Integer totalCounts;//数据总量
private Integer totalPages;//总页数
private Integer beginRow;//起始行
public Page(Integer pageIndex, Integer pageSize) {
this.pageIndex = pageIndex;
this.pageSize = pageSize;
this.setBeginRow((pageIndex-1) * pageSize);
}
public Page(Integer pageIndex) {
this(pageIndex,5);
}
public Integer getPageIndex() {
return pageIndex;
}
public void setPageIndex(Integer pageIndex) {
this.pageIndex = pageIndex;
}
public Integer getPageSize() {
return pageSize;
}
public void setPageSize(Integer pageSize) {
this.pageSize = pageSize;
}
public Integer getTotalCounts() {
return totalCounts;
}
public void setTotalCounts(Integer totalCounts) {
this.totalCounts = totalCounts;
this.setTotalPages(totalCounts % pageSize == 0?totalCounts/pageSize:totalCounts/pageSize+1);
}
public Integer getTotalPages() {
return totalPages;
}
public void setTotalPages(Integer totalPages) {
this.totalPages = totalPages;
}
public Integer getBeginRow() {
return beginRow;
}
public void setBeginRow(Integer beginRow) {
this.beginRow = beginRow;
}
}
4.3.5 EmpManagerDao
public interface EmpManagerDao {
EmpManager select(String username);
}
4.3.6 EmpDao
public interface EmpDao {
int insert(Emp emp);
int delete(int id);
int update(Emp emp);
Emp select(int id);
//分页查询所有
List<Emp> selectAll(Page page);
//查询数据总行数
long selectCounts();
}
4.3.7 EmpManagerDaoImpl
public class EmpManagerDaoImpl implements EmpManagerDao {
private QueryRunner queryRunner = new QueryRunner();
@Override
public EmpManager select(String username) {
try {
EmpManager empManager = queryRunner.query(DbUtils.getConnection(), "select * from empManager where username=?", new BeanHandler<EmpManager>(EmpManager.class), username);
return empManager;
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return null;
}
}
4.3.8 EmpDaoImpl
package com.dz.dao.impl;
import com.dz.dao.EmpDao;
import com.dz.entity.Emp;
import com.dz.entity.Page;
import com.dz.utils.DbUtils;
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 java.sql.SQLException;
import java.util.List;
public class EmpDaoImpl implements EmpDao {
private QueryRunner queryRunner = new QueryRunner();
@Override
public int insert(Emp emp) {
try {
return queryRunner.update(DbUtils.getConnection(), "insert into emp(name,salary,age) values(?,?,?)", emp.getName(), emp.getSalary(), emp.getAge());
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return 0;
}
@Override
public int delete(int id) {
try {
return queryRunner.update(DbUtils.getConnection(),"delete from emp where id=?",id);
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return 0;
}
@Override
public int update(Emp emp) {
try {
return queryRunner.update(DbUtils.getConnection(),"update emp set name=?,salary=?,age=? where id=?",emp.getName(),emp.getSalary(),emp.getAge(),emp.getId());
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return 0;
}
@Override
public Emp select(int id) {
try {
return queryRunner.query(DbUtils.getConnection(),"select * from emp where id=?",new BeanHandler<Emp>(Emp.class),id);
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return null;
}
@Override
public List<Emp> selectAll(Page page) {
try {
return queryRunner.query(DbUtils.getConnection(),"select * from emp limit ?,?",new BeanListHandler<Emp>(Emp.class),page.getBeginRow(),page.getPageSize());
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return null;
}
@Override
public long selectCounts() {
try {
return queryRunner.query(DbUtils.getConnection(),"select count(*) from emp",new ScalarHandler<>());
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return 0;
}
}
4.3.9 EmpManagerService
public interface EmpManagerService {
EmpManager login(String username,String password);
}
4.3.10 EmpService
public interface EmpService {
int addEmp(Emp emp);
int removeEmp(int id);
int modifyEmp(Emp emp);
Emp showEmp(int id);
List<Emp> showAllEmp(Page page);
}
4.3.11 EmpManagerServiceImpl
public class EmpManagerServiceImpl implements EmpManagerService {
private EmpManagerDao empManagerDao = new EmpManagerDaoImpl();
@Override
public EmpManager login(String username, String password) {
EmpManager empManager = null;
try {
DbUtils.begin();
EmpManager temp = empManagerDao.select(username);
if (temp != null) {
if (temp.getPassword().equals(password)) {
empManager = temp;
}
}
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return empManager;
}
}
4.3.12 EmpServiceImpl
public class EmpServiceImpl implements EmpService {
private EmpDao empDao = new EmpDaoImpl();
@Override
public int addEmp(Emp emp) {
int result = 0;
try {
DbUtils.begin();
result = empDao.insert(emp);
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return result;
}
@Override
public int removeEmp(int id) {
int result = 0;
try {
DbUtils.begin();
result = empDao.delete(id);
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return result;
}
@Override
public int modifyEmp(Emp emp) {
int result = 0;
try {
DbUtils.begin();
result = empDao.update(emp);
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return result;
}
@Override
public Emp showEmp(int id) {
Emp emp = null;
try {
DbUtils.begin();
emp = empDao.select(id);
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return emp;
}
@Override
public List<Emp> showAllEmp(Page page) {
List<Emp> empList = new ArrayList<>();
try {
DbUtils.begin();
long counts = empDao.selectCounts();
page.setTotalCounts((int)counts);//赋值总条数,计算总页数
empList = empDao.selectAll(page);
DbUtils.commit();
} catch (Exception e) {
DbUtils.rollback();
e.printStackTrace();
}
return empList;
}
}
4.3.13 login.jsp
<%@ page import="java.util.Date" %>
<%@ page import="java.time.LocalDate" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登陆页面</title>
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/css/style.css" />
</head>
<body>
<div id="wrap">
<div id="top_content">
<div id="header">
<div id="rightheader">
<p>
<%=LocalDate.now()%> <br />
</p>
</div>
<div id="topheader">
<h1 id="title">
<a href="#">管理员登陆</a>
</h1>
</div>
<div id="navigation"></div>
</div>
<div id="content">
<p id="whereami"></p>
<h1>login</h1>
<form action="${pageContext.request.contextPath}/manager/empManagerLogin" method="post">
<table cellpadding="0" cellspacing="0" border="0"
class="form_table">
<tr>
<td valign="middle" align="right">用户名:</td>
<td valign="middle" align="left"><input type="text"
class="inputgri" name="username" /></td>
</tr>
<tr>
<td valign="middle" align="right">密码:</td>
<td valign="middle" align="left"><input type="password"
class="inputgri" name="password" /></td>
</tr>
<tr>
<td valign="middle" align="right">验证码:</td>
<td valign="middle" align="left"><input type="text"
class="inputgri" name="validateCode" /><img src="${pageContext.request.contextPath}/createCode"
alt="验证码"></td>
</tr>
</table>
<p>
<input type="submit" class="button" value="Submit »" />
</p>
</form>
</div>
</div>
<div id="footer">
<div id="footer_bg">EMS/login.jsp</div>
</div>
</div>
</body>
</html>
4.3.14 empList.jsp
<%@ page import="java.time.LocalDate" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>用户列表</title>
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/css/style.css" />
</head>
<body>
<div id="wrap">
<div id="top_content">
<div id="header">
<div id="rightheader">
<p>
<%=LocalDate.now()%>
<br />
</p>
</div>
<div id="topheader">
<h1 id="title">
<a href="#">员工列表</a>
</h1>
</div>
<div id="navigation">
</div>
</div>
<div id="content">
<p id="whereami">
</p>
<h1>
${empManager.username},Welcome!
</h1>
<table class="table">
<tr class="table_header">
<td>
ID
</td>
<td>
Name
</td>
<td>
Salary
</td>
<td>
Age
</td>
<td>
Operation
</td>
</tr>
<%--隔行变色--%>
<c:forEach var="emp" items="${empList}" varStatus="e">
<c:if test="${e.count % 2 != 0}">
<tr class="row1">
</c:if>
<c:if test="${e.count % 2 == 0}">
<tr class="row2">
</c:if>
<td>
${emp.id}
</td>
<td>
${emp.name}
</td>
<td>
${emp.salary}
</td>
<td>
${emp.age}
</td>
<td>
<a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/removeEmp?id=${emp.id}'/> ">delete emp</a> <a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/showEmp?id=${emp.id}'/> ">update emp</a>
</td>
</tr>
</c:forEach>
<tr>
<td colspan="5">
<a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/showAllEmp?pageIndex=1'/> ">首页</a>
<c:if test="${page.pageIndex > 1}">
<a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/showAllEmp?pageIndex=${page.pageIndex-1}'/> ">上一页</a>
</c:if>
<c:if test="${page.pageIndex == 1}">
<a>上一页</a>
</c:if>
<c:if test="${page.pageIndex < page.totalPages}">
<a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/showAllEmp?pageIndex=${page.pageIndex+1}'/> ">下一页</a>
</c:if>
<c:if test="${page.pageIndex == page.totalPages}">
<a>下一页</a>
</c:if>
<a href="<c:url context='${pageContext.request.contextPath}' value='/manager/safe/showAllEmp?pageIndex=${page.totalPages}'/> ">尾页</a>
</td>
</tr>
</table>
<p>
<input type="button" class="button" value="Add Employee" onclick="location='${pageContext.request.contextPath}/manager/safe/addEmp.jsp'"/>
</p>
</div>
</div>
<div id="footer">
<div id="footer_bg">
empList.jsp
</div>
</div>
</div>
</body>
</html>
4.3.15 addEmp.jsp
<%@ page import="java.time.LocalDate" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>新增员工界面</title>
<link rel="stylesheet" type="text/css" href="${pageContext.request.contextPath}/css/style.css" />
</head>
<body>
<div id="wrap">
<div id="top_content">
<div id="header">
<div id="rightheader">
<p>
<%=LocalDate.now()%>
<br />
</p>
</div>
<div id="topheader">
<h1 id="title">
<a href="#">新增员工</a>
</h1>
</div>
<div id="navigation">
</div>
</div>
<div id="content">
<p id="whereami">
</p>
<h1>
add Emp info:
</h1>
<form action="${pageContext.request.contextPath}/manager/safe/addEmp" method="post">
<table cellpadding="0" cellspacing="0" border="0"
class="form_table">
<tr>
<td valign="middle" align="right">
name:
</td>
<td valign="middle" align="left">
<input type="text" class="inputgri" name="name" />
</td>
</tr>
<tr>
<td valign="middle" align="right">
salary:
</td>
<td valign="middle" align="left">
<input type="text" class="inputgri" name="salary" />
</td>
</tr>
<tr>
<td valign="middle" align="right">
age:
</td>
<td valign="middle" align="left">
<input type="text" class="inputgri" name="age" />
</td>
</tr>
</table>
<p>
<input type="submit" class="button" value="Confirm" />
</p>
</form>
</div>
</div>
<div id="footer">
<div id="footer_bg">
addEmp.jsp
</div>
</div>
</div>
</body>
</html>
4.3.16 EmpManagerLoginController
@WebServlet(name = "EmpManagerLoginController",value = "/manager/empManagerLogin")
public class EmpManagerLoginController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
String inputVCode = request.getParameter("validateCode");
String code = (String) request.getSession().getAttribute("code");
if (!inputVCode.isEmpty() && inputVCode.equalsIgnoreCase(code)) {
EmpManagerService empManagerService = new EmpManagerServiceImpl();
EmpManager empManager = empManagerService.login(username, password);
if (empManager != null) {
HttpSession session = request.getSession();
session.setAttribute("empManager",empManager);
response.sendRedirect(request.getContextPath() + "/manager/safe/showAllEmp");
}else {
response.sendRedirect(request.getContextPath() + "/login.jsp");
}
}else {
response.sendRedirect(request.getContextPath() + "/login.jsp");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.17 CreateCodeController
@WebServlet(name = "CreateCodeController",value = "/createCode")
public class CreateCodeController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ValidateCode validateCode = new ValidateCode(200,30,4,10);
String code = validateCode.getCode();
HttpSession session = request.getSession();
session.setAttribute("code",code);
validateCode.write(response.getOutputStream());
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.18 ShowAllEmpController
@WebServlet(name = "ShowAllEmpController",value = "/manager/safe/showAllEmp")
public class ShowAllEmpController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String pageIndex = request.getParameter("pageIndex");
if (pageIndex == null) {
pageIndex = "1";
}
Page page = new Page(Integer.valueOf(pageIndex));
EmpService empService = new EmpServiceImpl();
List<Emp> empList = empService.showAllEmp(page);
if (empList != null) {
request.setAttribute("page",page);
request.setAttribute("empList",empList);
request.getRequestDispatcher("/manager/safe/empList.jsp").forward(request, response);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.19 AddEmpController
@WebServlet(name = "AddEmpController",value = "/manager/safe/addEmp")
public class AddEmpController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String name = request.getParameter("name");
Double salary = Double.valueOf(request.getParameter("salary"));
Integer age = Integer.valueOf(request.getParameter("age"));
Emp emp = new Emp(name,salary,age);
EmpService empService = new EmpServiceImpl();
empService.addEmp(emp);
response.sendRedirect(request.getContextPath()+"/manager/safe/showAllEmp");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.20 RemoveEmpController
@WebServlet(name = "RemoveEmpController",value = "/manager/safe/removeEmp")
public class RemoveEmpController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Integer id = Integer.valueOf(request.getParameter("id"));
EmpService empService = new EmpServiceImpl();
empService.removeEmp(id);
response.sendRedirect(request.getContextPath() + "/manager/safe/showAllEmp");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.21 ShowEmpController
@WebServlet(name = "ShowEmpController",value = "/manager/safe/showEmp")
public class ShowEmpController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Integer id = Integer.valueOf(request.getParameter("id"));
EmpService empService = new EmpServiceImpl();
Emp emp = empService.showEmp(id);
request.setAttribute("emp",emp);
request.getRequestDispatcher("/manager/safe/updateEmp.jsp").forward(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.22 UpdateEmpController
@WebServlet(name = "UpdateEmpController",value = "/manager/safe/updateEmp")
public class UpdateEmpController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//收参
Integer id = Integer.valueOf(request.getParameter("id"));
String name = request.getParameter("name");
Double salary = Double.valueOf(request.getParameter("salary"));
Integer age = Integer.valueOf(request.getParameter("age"));
Emp emp = new Emp(id,name,salary,age);
EmpService empService = new EmpServiceImpl();
empService.modifyEmp(emp);
response.sendRedirect(request.getContextPath()+"/manager/safe/showAllEmp");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}
4.3.23 EncodingFilter
@WebFilter(filterName = "EncodingFilter",value = "/manager/*")
public class EncodingFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
//设置统一编码格式
req.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=UTF-8");
chain.doFilter(req, resp);
}
public void init(FilterConfig config) throws ServletException {
}
}
4.3.24 CheckFilter
@WebFilter(filterName = "CheckFilter",value = "/manager/safe/*")
public class CheckFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
HttpServletRequest request = (HttpServletRequest)req;
HttpServletResponse response = (HttpServletResponse)resp;
HttpSession session = request.getSession();
EmpManager empManager = (EmpManager) session.getAttribute("empManager");
if (empManager != null) {
chain.doFilter(request, response);
}else {
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
}
public void init(FilterConfig config) throws ServletException {
}
}
五. Web开发总结
5.1 开发流程
在Web开发流程中, 遵守以下开发顺序:
- DAO
- table
- entity
- DAO接口
- DAO实现
- Service
- Service接口
- Service实现(调用DAO实现类, 并控制事务)
- Controller(处理请求的Servlet)
- 收集请求中的数据
- 调用业务功能(调用Service实现类)
- 在相应合适的作用域中存储数据
- 流程跳转(forward|sendRedirect)--->.jsp
- JSP
- 在作用域中获取数据
- 使用EL+JSTL将数据嵌套在HTML标签中
- Filter
- EncodingFilter: 统一编码格式过滤器
- CheckFilter: 权限验证过滤器