Servlet总览

 <Connector port="8080" protocol="HTTP/1.1"
               connectionTimeout="20000"
               redirectPort="8443" />

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;

public class MyServlet implements Servlet{
	public void init(ServletConfig config) throws ServletException{
	}
    
	public void service(ServletRequest request,ServletResponse response) throws ServletException,IOException{
		System.out.println("My First Servlet!");
	}
    
	public void destroy(){
	
	}
    
	public ServletConfig getServletConfig(){
		return null;	
	}	
    
	public String getServletInfo(){
		return null;
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  	
  <!--1、添加servlet节点-->
  <servlet>
  	<servlet-name>my</servlet-name>
    <servlet-class>MyServlet</servlet-class>
  </servlet>
  <!--2、添加servlet-mapping节点  -->
  <servlet-mapping>
  	<servlet-name>my</servlet-name>
  	<url-pattern>/myservlet</url-pattern>
  </servlet-mapping>
  
</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  	
  <!--1添加servlet节点  -->
  <servlet>
  	<servlet-name>MyServlet</servlet-name>
    <servlet-class>com.qf.servlet.MyServlet</servlet-class>
  </servlet>
  <!--2添加servlet-mapping节点  -->
  <servlet-mapping>
  	<servlet-name>MyServlet</servlet-name>
  	<url-pattern>/myservlet</url-pattern>
  </servlet-mapping>
  
</web-app>

/**
 * Servlet创建的第一种方式：实现接口Servlet
 * */
public class HelloServlet2 implements Servlet{

	@Override
	public void destroy() {
	}

	@Override
	public ServletConfig getServletConfig() {
		return null;
	}

	@Override
	public String getServletInfo() {
		return null;
	}

	@Override
	public void init(ServletConfig arg0) throws ServletException {
	}
	@Override
	public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
		System.out.println("OK");
		response.getWriter().println("welcome use servlet");
	}
}

/**
 * Servlet implementation class HelloServlet
 * Servlet的第二种创建方式，继承HttpServlet.也是开发中推荐的
 * 
 */
public class HelloServlet extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		response.getWriter().print("welcome use servlet");
	}
    
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>Web_Day11</display-name>
  <!--Servlet的第二种配置  -->
  <!--Servlet配置  -->
  <servlet>
  <!--名称  -->
    <servlet-name>hello2</servlet-name>
    <!--Servlet的全称类名  -->
    <servlet-class>com.qf.web.servlet.HelloServlet</servlet-class>
    <!--启动的优先级，数字越小越先起作用  -->
    <load-on-startup>1</load-on-startup>
  </servlet>
  <!--映射配置  -->
  <servlet-mapping>
  <!--名称  -->
    <servlet-name>hello2</servlet-name>
    <!--资源的匹配规则：精确匹配  -->
    <url-pattern>/hello2</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>login.html</welcome-file>
  </welcome-file-list>
</web-app>

/**
 * Servlet implementation class HelloServlet
 * 演示Servlet注解式配置
 */
@WebServlet("/hello")
public class HelloServlet extends HttpServlet {
	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		response.getWriter().print("OK");
	}
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>欢迎页面</title>
</head>
<body>
<h1>欢迎你</h1>
<div>
<form action="HelloServlet" method="post">
<label>姓名：</label><input type="text" name="name"><br/>
<label>年龄：</label><input type="text"  name="age"><br/>
<input type="submit" value="提交">
</form>
</div>
</body>
</html>

@WebServlet("/HelloServlet")
public class HelloServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//获取表单提交的姓名
		String name=request.getParameter("name");
		//获取年龄
		String age=request.getParameter("age");
		//服务端输出打印
		System.out.println(request.getRemoteAddr()+"发来信息：姓名："+name+"---->年龄："+age);
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

/**
 * Servlet implementation class HelloServlet
 * 演示Servlet的GET请求,中文乱码的问题
 * 
 */
@WebServlet("/GETServlet")
public class GetServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//获取表单提交的姓名
		String name=request.getParameter("name");
		name=new String(name.getBytes("ISO8859-1"),"UTF-8");
		//获取年龄
		String age=request.getParameter("age");
		//服务端输出打印
		System.out.println(request.getRemoteAddr()+"发来信息：姓名："+name+"---->年龄："+age);
	}
	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

/**
 * Servlet implementation class HelloServlet
 * 演示Servlet的GET请求,中文乱码的问题
 * 
 */
@WebServlet("/GETServlet")
public class GetServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
    
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//设置请求参数的编码格式--对GET无效
        request.setCharacterEncoding("UTF-8");
		//获取表单提交的信息
		String name=request.getParameter("msg");
		//服务端输出打印
		System.out.println(request.getRemoteAddr()+"发来信息："+msg);
	}
}

//获取请求参数代码省略
//获取输出流
PrintWriter out=response.getWriter();
out.println("<html>");
out.println("<head><title>login</title></head>");
out.println("<body>");
out.println("<h1>Login Success!!!</h1>");
//out.println("<h1>登录成功!!!</h1>");
out.println("</body>");
out.println("</html>");

response.setCharacterEncoding("utf-8");//设置响应编码格式为utf-8
response.setHeader("Content-type","text/html;charset=UTF-8");

response.setContentType("text/html;charset=UTF-8");

CREATE TABLE admin(
	username VARCHAR(20) PRIMARY KEY,
	password VARCHAR(20) NOT NULL,
    phone varchar(11) NOT NULL,
    address varchar(20) NOT NULL
)CHARSET=utf8;
INSERT INTO admin(username,PASSWORD,phone,address)
VALUES('gavin','123456','12345678901','北京市昌平区');
INSERT INTO admin(username,PASSWORD,phone,address)
VALUES('aaron','123456','12345678901','北京市昌平区');

package com.qf.servletProject.utils;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.pool.DruidDataSourceFactory;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

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 connection = THREAD_LOCAL.get();
        try {
            if (connection == null) {
                connection = ds.getConnection();
                THREAD_LOCAL.set(connection);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static void begin() {
        Connection connection = null;
        try {
            connection = getConnection();
            connection.setAutoCommit(false);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void commit() {
        Connection connection = null;
        try {
            connection = getConnection();
            connection.commit();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeAll(connection, null, null);
        }
    }

    public static void rollback() {
        Connection connection = null;
        try {
            connection = getConnection();
            connection.rollback();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeAll(connection, null, null);
        }
    }

    public static void closeAll(Connection connection, Statement statement, ResultSet resultSet) {
        try {
            if (resultSet != null) {
                resultSet.close();
            }
            if (statement != null) {
                statement.close();
            }
            if (connection != null) {
                connection.close();
                THREAD_LOCAL.remove();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

package com.qf.servletProject.dao.impl;

import com.qf.servletProject.dao.AdminDao;
import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.utils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import java.sql.SQLException;
import java.util.List;

public class AdminDaoImpl implements AdminDao {
    private QueryRunner queryRunner = new QueryRunner();
    @Override
    public int insert(Admin admin) {
        return 0;
    }

    @Override
    public int delete(String username) {
        return 0;
    }

    @Override
    public int update(Admin admin) {
        return 0;
    }

    @Override
    public Admin select(String username) {
        try {
            Admin admin = queryRunner.query(DbUtils.getConnection(),"select * from admin where username=?;",new BeanHandler<Admin>(Admin.class),username);
            return admin;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public List<Admin> selectAll() {
        try {
            List<Admin> admins = queryRunner.query(DbUtils.getConnection(),"select * from admin",new BeanListHandler<Admin>(Admin.class));
            return admins;
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }
}

package com.qf.servletProject.service.impl;

import com.qf.servletProject.dao.AdminDao;
import com.qf.servletProject.dao.impl.AdminDaoImpl;
import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.service.AdminService;
import com.qf.servletProject.utils.DbUtils;

import java.util.List;

public class AdminServiceImpl implements AdminService {
    private AdminDao adminDao = new AdminDaoImpl();
    @Override
    public Admin login(String username, String password) {
        Admin result = null;
        try {
            DbUtils.begin();
            Admin admin = adminDao.select(username);
            if(admin!=null){
                if(admin.getPassword().equals(password)){
                    result = admin;
                }
            }
            DbUtils.commit();
        } catch (Exception e) {
            DbUtils.rollback();
            e.printStackTrace();
        }
        return result;
    }

    @Override
    public List<Admin> showAllAdmin() {
        List<Admin> admins = null;
        try {
            DbUtils.begin();
            admins = adminDao.selectAll();
            DbUtils.commit();
        } catch (Exception e) {
            DbUtils.rollback();
            e.printStackTrace();
        }

        return admins;
    }
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登录页面</title>
</head>
<body>
    <form action="/WebProject_war_exploded/login" method="post">
        用户名:<input type="text" name="username" /><br/>
        密码:<input type="password" name="password"><br/>
        <input type="submit" value="登录" />
    </form>
</body>
</html>

package com.qf.servletProject.servlet;

import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.service.AdminService;
import com.qf.servletProject.service.impl.AdminServiceImpl;

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.IOException;
import java.io.PrintWriter;

@WebServlet(value = "/login")
public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        resp.setContentType("text/html;charset=UTF-8");
        //1.收参
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //2.调用业务逻辑
        AdminService adminService = new AdminServiceImpl();
        Admin admin = adminService.login(username,password);
        //3.处理结果
        PrintWriter printWriter = resp.getWriter();
        if(admin!=null){
            //响应给客户端一个结果页面，显示登录成功
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<meta charset='UTF-8'>");
            printWriter.println("<title>结果页面</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h1>登录成功！</h1>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        }else{
            //响应给客户端一个结果页面，显示登录失败！
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<meta charset='UTF-8'>");
            printWriter.println("<title>结果页面</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h1>登录失败！</h1>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

package com.qf.servletProject.servlet;

import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.service.AdminService;
import com.qf.servletProject.service.impl.AdminServiceImpl;

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.IOException;
import java.io.PrintWriter;
import java.util.List;

@WebServlet(value = "/showall")
public class ShowAllAdminServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf-8");
        AdminService adminService = new AdminServiceImpl();

        List<Admin> adminList = adminService.showAllAdmin();

        PrintWriter printWriter = resp.getWriter();

        if(adminList!=null){
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<meta charset='UTF-8'>");
            printWriter.println("<title>显示所有</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<table border='1'>");
            printWriter.println("   <tr>");
            printWriter.println("       <td>username</td>");
            printWriter.println("       <td>password</td>");
            printWriter.println("       <td>phone</td>");
            printWriter.println("       <td>address</td>");
            printWriter.println("   </tr>");
            for(Admin admin : adminList){
                printWriter.println("   <tr>");
                printWriter.println("       <td>"+admin.getUsername()+"</td>");
                printWriter.println("       <td>"+admin.getPassword()+"</td>");
                printWriter.println("       <td>"+admin.getPhone()+"</td>");
                printWriter.println("       <td>"+admin.getAddress()+"</td>");
                printWriter.println("   </tr>");
            }
            printWriter.println("</table>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        }else{
            printWriter.println("<html>");
            printWriter.println("<head>");
            printWriter.println("<meta charset='UTF-8'>");
            printWriter.println("<title>显示所有</title>");
            printWriter.println("</head>");
            printWriter.println("<body>");
            printWriter.println("<h3>当前没有用户！</h3>");
            printWriter.println("</body>");
            printWriter.println("</html>");
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

/**
 * Servlet implementation class LifeServlet
 * 演示Servlet的生命周期：
 * 1、实例化
 * 2、init:初始化
 * 3、service：服务
 * 4、destory：销毁
 */
@WebServlet("/lifeservlet")
public class LifeServlet extends HttpServlet {
    
    public LifeServlet() {
        super();
        System.out.println("1、完成了实例化");
    }
    @Override
    public void init() throws ServletException {
    	super.init();
    	System.out.println("2、完成了初始化");
    }

	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		System.out.println("3、就绪中");
		response.getWriter().append("Served at: ").append(request.getContextPath());
	}

	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
	
	@Override
	public void destroy() {
		super.destroy();
		System.out.println("4、销毁了");
	}
}

package com.qf.servlet3;

import javax.servlet.ServletException;
import javax.servlet.SingleThreadModel;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class SafeServlet extends HttpServlet  implements SingleThreadModel {
     //private String message = "";

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String message = "";
        //假设1、接收参数
        //2、调用业务逻辑 得到登录结果
        message = "登录成功";//登录失败！
        PrintWriter printWriter = resp.getWriter();
        printWriter.println(message);

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

		//创建Cookie
		Cookie ck=new Cookie("code", code);
		ck.setPath("/webs");//设置Cookie的路径
		ck.setMaxAge(-1);//内存存储，取值有三种：>0有效期，单位秒；=0立马销毁；<0浏览器结束销毁,默认-1
		response.addCookie(ck);//添加到response对象中，响应时发送给客户端
        //注意：有效路径: 当前访问资源的上一级目录，不带主机名

//获取所有的Cookie
Cookie[] cks=request.getCookies();
		//遍历Cookie
		for(Cookie ck:cks){
          //检索出自己的Cookie
			if(ck.getName().equals("code"))
			{
              //记录Cookie的值
				code=ck.getValue();
				break;
			}
		}

	//修改Cookie
    Cookie ck=new Cookie("code", code);
    ck.setPath("/webs");//设置Cookie的路径
    ck.setMaxAge(-1);//内存存储，取值有三种：>0有效期，单位秒；=0失效；<0浏览器结束销毁
    response.addCookie(ck);//让浏览器添加Cookie

 // 使用中文的 Cookie. name 与 value 都使用 UTF-8 编码. 
    Cookie cookie = new Cookie(
        URLEncoder.encode("姓名", "UTF-8"), 
        URLEncoder.encode("老邢", "UTF-8"));
    // 发送到客户端   
    response.addCookie(cookie);

    if(request.getCookies() != null){
        for(Cookie cc : request.getCookies()){
            String cookieName = URLDecoder.decode(cc.getName(), "UTF-8");
            String cookieValue = URLDecoder.decode(cc.getValue(), "UTF-8");
            out.println(cookieName + "=");
            out.println(cookieValue + "; <br/>");
        }
    }
    else{
        out.println("Cookie 已经写入客户端. 请刷新页面. ");
    }

        //获取Session对象
		HttpSession session=request.getSession();
		System.out.println("Id："+session.getId());//唯一标记，

	session.setAttribute("key",value);//以键值对形式存储在session作用域中。

	session.getAttribute("key");//通过String类型的key访问Object类型的value

	session.removeAttribute("key");//通过键移除session作用域中的值

package com.qf.sessions;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "SessionServlet",value = "/ss")
public class SessionServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.通过request对象获取Session对象
        HttpSession session = request.getSession();

        //2.使用session保存数据
        session.setAttribute("username","gavin");
        request.setAttribute("password","123456");

        response.sendRedirect("/WebProject_war_exploded/getValue");
        System.out.println(session.getId());
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }
}

package com.qf.sessions;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "GetValueServlet",value = "/getValue")
public class GetValueServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.通过request获取session对象
        HttpSession session = request.getSession();

        String password = (String)request.getAttribute("password");
        String s = (String) session.getAttribute("username");

        System.out.println("从session中获得了："+s);
        System.out.println("从reqeust中获得了："+password);


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }
}

	session.setMaxInactiveInterval(60*60);//设置session最大有效期为一小时

	session.invalidate();//手工销毁

CREATE TABLE Manager(
	username VARCHAR(20) PRIMARY KEY,
    password VARCHAR(20) NOT NULL
)charset=utf8;

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>管理员登录</title>
    </head>
    <body>
    <form action="/WebProject_war_exploded/loginMgr" method="post">
        用户名：<input type="text" name="username"/><br/>
        密码：<input type="password" name="password" /><br/>
        <input type="submit" value="登录">
    </form>
</body>
</html>

package com.qf.servletProject.servlet.controller;

import com.qf.servletProject.entity.Manager;
import com.qf.servletProject.service.ManagerService;
import com.qf.servletProject.service.impl.ManagerServiceImpl;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "LoginMgrController",value = "/loginMgr")
public class LoginMgrController extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.处理乱码
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=utf-8");
        //2.收参
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        //3.调用业务方法
        ManagerService managerService = new ManagerServiceImpl();
        Manager mgr = managerService.login(username,password);
        //4.处理结果，流程跳转
        if(mgr!=null){
            //登录成功
            //将管理员信息存储在Session里
            HttpSession session = request.getSession();
            session.setAttribute("mgr",mgr);
            //跳转  目标、方式
            response.sendRedirect("/WebProject_war_exploded/showallcontroller");
        }else{
            //登录失败
            response.sendRedirect("/WebProject_war_exploded/loginMgr.html");
        }
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

package com.qf.servletProject.servlet.controller;

import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.entity.Manager;
import com.qf.servletProject.service.AdminService;
import com.qf.servletProject.service.impl.AdminServiceImpl;

import javax.servlet.RequestDispatcher;
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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;

@WebServlet(value = "/showallcontroller")
public class ShowAllAdminController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //通过HttpSession完成权限控制
        HttpSession session = req.getSession();
        Manager mgr  =(Manager)session.getAttribute("mgr");
        if(mgr !=null){
            //只负责调用业务逻辑功能
            AdminService adminService = new AdminServiceImpl();

            List<Admin> adminList = adminService.showAllAdmin();

            //request作用域存储数据
            req.setAttribute("admins",adminList);
            //通过转发 跳转到显示结果servlet
            req.getRequestDispatcher("/showalljsp").forward(req,resp);
        }else{
            resp.sendRedirect("/WebProject_war_exploded/loginMgr.html");
        }

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

/**
 * Servlet implementation class CreateCode
 * 验证码的生成
 */
@WebServlet("/createcode")
public class CreateCode extends HttpServlet {
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		ValidateCode vc=new ValidateCode(200, 30, 4, 10);
		String code=vc.getCode();
		System.out.println(request.getRemoteAddr()+":生成:"+code);
		//使用Session存储生成的验证码
		HttpSession session=request.getSession();
      	session.setAttribute("code",code);
        //响应给客户端
		vc.write(response.getOutputStream());
	}

	/**
	 * @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);
	}
}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>管理员登录</title>
    </head>
    <body>
    <form action="/WebProject_war_exploded/loginMgr" method="post">
        用户名：<input type="text" name="username"/><br/>
        密码：<input type="password" name="password" /><br/>
        验证码：<input type="text" name="inputVcode"/> <img src="/WebProject_war_exploded/createcode" /><br/>
        <input type="submit" value="登录">
    </form>
</body>
</html>

package com.qf.servletProject.servlet.controller;

import com.qf.servletProject.entity.Manager;
import com.qf.servletProject.service.ManagerService;
import com.qf.servletProject.service.impl.ManagerServiceImpl;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "LoginMgrController", value = "/loginMgr")
public class LoginMgrController extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.处理乱码
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=utf-8");

        //2.收参
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String inputVcode = request.getParameter("inputVcode");

        String codes = (String) request.getSession().getAttribute("codes");
        if (!inputVcode.isEmpty() && inputVcode.equalsIgnoreCase(codes)) {

            //3.调用业务方法
            ManagerService managerService = new ManagerServiceImpl();
            Manager mgr = managerService.login(username, password);
            //4.处理结果，流程跳转
            if (mgr != null) {
                //登录成功
                //将管理员信息存储在Session里
                HttpSession session = request.getSession();
                session.setAttribute("mgr", mgr);
                //跳转  目标、方式
                response.sendRedirect("/WebProject_war_exploded/showallcontroller");
            } else {
                //登录失败
                response.sendRedirect("/WebProject_war_exploded/loginMgr.html");
            }
        }else{
            response.sendRedirect("/WebProject_war_exploded/loginMgr.html");
        }

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }
}

String realpath=servletContext.getRealPath("/");

System.out.println(servletContext.getContextPath());//上下文路径（应用程序名称）
System.out.println(request.getContextPath());

package com.qf.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class Servlet3
 */
@WebServlet("/servlet3")
public class Servlet3 extends HttpServlet {
	
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		
		ServletContext application = request.getServletContext();
		Integer count=(Integer) application.getAttribute("count");
		if(count==null) {
			count=1;
			application.setAttribute("count", count);
		}else {
			count++;
			application.setAttribute("count", count);
		}
		
		PrintWriter out=response.getWriter();
		out.write("servlet共访问次数："+count);
		
	}

	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		doGet(request, response);
	}

}

package com.qf.web.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter("/myservlet1")//过滤路径
public class MyFilter1 implements Filter {

    //初始化过滤器
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        System.out.println("过滤器初始化了........init...  "+filterConfig);
    }

    //执行过滤
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        System.out.println("过滤前........doFilter ");
        //放行
        chain.doFilter(request, response);

        System.out.println("过滤后.......doFilter");

    }

    //销毁
    @Override
    public void destroy() {
        System.out.println("销毁了.....destroy");
    }
}

<!--过滤器的xml配置  -->
  <filter>
  <!--名称-->
    <filter-name>sf</filter-name>
    <!--过滤器类全称-->
    <filter-class>com.qf.web.filter.SecondFilter</filter-class>
  </filter>
 <!--映射路径配置-->
  <filter-mapping>
     <!--名称-->
    <filter-name>sf</filter-name>
     <!--过滤的url匹配规则和Servlet类似-->
    <url-pattern>/*</url-pattern>
  </filter-mapping>

package com.qf.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
@WebFilter(value = "/*")
public class EncodingFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //统一处理请求和响应的乱码
        servletRequest.setCharacterEncoding("UTF-8");
        servletResponse.setContentType("text/html;charset=utf-8");

        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}

package com.qf.servletProject.servlet.controller;

import com.qf.servletProject.entity.Admin;
import com.qf.servletProject.entity.Manager;
import com.qf.servletProject.service.AdminService;
import com.qf.servletProject.service.impl.AdminServiceImpl;

import javax.servlet.RequestDispatcher;
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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;

@WebServlet(value = "/showallcontroller")
public class ShowAllAdminController extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        //通过HttpSession完成权限控制
//        HttpSession session = req.getSession();
//        Manager mgr  =(Manager)session.getAttribute("mgr");
//        if(mgr !=null){
            //只负责调用业务逻辑功能
            AdminService adminService = new AdminServiceImpl();

            List<Admin> adminList = adminService.showAllAdmin();

            //request作用域存储数据
            req.setAttribute("admins",adminList);
            //通过转发 跳转到显示结果servlet
            req.getRequestDispatcher("/showalljsp").forward(req,resp);
//        }else{
//            resp.sendRedirect("/WebProject_war_exploded/loginMgr.html");
//        }

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}

package com.qf.servletProject.filter;

import com.qf.servletProject.entity.Manager;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@WebFilter(value = "/showallcontroller")
public class CheckFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //权限验证   验证管理员是否登录！
        //向下转型  拆箱
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;
        HttpSession session =request.getSession();
        Manager mgr = (Manager) session.getAttribute("mgr");
        if(mgr!=null){//登录过！
            filterChain.doFilter(request,response);
        }else{
            response.sendRedirect(request.getContextPath()+"/loginMgr.html");
        }

    }

    @Override
    public void destroy() {

    }
}

CREATE DATABASE EMP;

CREATE TABLE EMP(
	ID INT PRIMARY KEY AUTO_INCREMENT,
    NAME VARCHAR(20) NOT NULL,
    SALARY DOUBLE NOT NULL,
    AGE INT NOT NULL
)CHARSET=UTF8;

CREATE TABLE EmpManager(
    USERNAME VARCHAR(20) NOT NULL,
    PASSWORD VARCHAR(20) NOT NULL
)CHARSET=UTF8;

package com.qf.emp.controller;

import com.qf.emp.entity.EmpManager;
import com.qf.emp.service.EmpManagerService;
import com.qf.emp.service.impl.EmpManagerServiceImpl;

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 javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet(name = "EmpManagerLoginController",value = "/manage/EmpManagerLoginController")
public class EmpManagerLoginController extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.收参
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String inputVcode = request.getParameter("inputVcode");

        //2.校验验证码
        String codes = (String)request.getSession().getAttribute("codes");
        if(!inputVcode.isEmpty() && inputVcode.equalsIgnoreCase(codes)){
            //调用业务逻辑实现登录
            EmpManagerService empManagerService = new EmpManagerServiceImpl();
            EmpManager empManager = empManagerService.login(username,password);
            if(empManager!=null){
                //登录成功
                //存储在session作用域
                HttpSession session = request.getSession();
                session.setAttribute("empManager",empManager);
                //跳转到查询所有的controller
                response.sendRedirect(request.getContextPath()+"/manage/safe/showAllEmpController");
            }else{
                response.sendRedirect(request.getContextPath()+"/login.html");
            }
        }else{
            //验证码输入错误，跳转到登录页面
            response.sendRedirect(request.getContextPath()+"/login.html");
        }
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }
}