Servlet（五）----Request登录案例

##  案例：用户登录

准备工作：

准备Maven  配置pom.xml

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>Login</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>Login Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.15</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/commons-logging/commons-logging -->
    <dependency>
      <groupId>commons-logging</groupId>
      <artifactId>commons-logging</artifactId>
      <version>1.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.9</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.mchange/mchange-commons-java -->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>mchange-commons-java</artifactId>
      <version>0.2.12</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-beans -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-beans</artifactId>
      <version>5.0.0.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</artifactId>
      <version>5.0.0.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.0.0.RELEASE</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.0.0.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter</artifactId>
      <version>RELEASE</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter</artifactId>
      <version>RELEASE</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>org.testng</groupId>
      <artifactId>testng</artifactId>
      <version>RELEASE</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>compile</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>jsp-api</artifactId>
      <version>2.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/commons-beanutils/commons-beanutils -->
    <dependency>
      <groupId>commons-beanutils</groupId>
      <artifactId>commons-beanutils</artifactId>
      <version>1.8.0</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>Login</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

User实体类：

package com.ftj.domain;

/**
 * 用户实体类javaBean
 */
public class User {
    private int id;
    private String username;
    private String password;
    private String gender;

    public User() {
    }

    public User(int id, String username, String password, String gender) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.gender = gender;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    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 String getHehe() {
        return gender;
    }

    public void setHehe(String gender) {
        this.gender = gender;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                ", gender='" + gender + '\'' +
                '}';
    }
}

UserDao

package com.ftj.dao;

/**
 * 操作数据中，user表的类
 */

import com.ftj.domain.User;
import com.ftj.util.JDBCUtil;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;

public class UserDao {

    //声明JDBCTemplate对象共用
    private JdbcTemplate template = new JdbcTemplate(JDBCUtil.getDataSource());

    /**
     * 登录方法
     *
     * @param loginUser 只有用户名和密码
     * @return 包含用户全部数据
     */
    public User login(User loginUser) {
        try {
            //1、编写sql
            String sql = "select * from user where username = ? and password = ?";
            //2、调用Query
            User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), loginUser.getUsername(), loginUser.getPassword());
            return user;
        } catch (Exception e) {
            e.printStackTrace();//记录日志
            return null;
        }
    }
}

登录验证

package com.ftj.servlet;

import com.ftj.dao.UserDao;
import com.ftj.domain.User;
import org.apache.commons.beanutils.BeanUtils;

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.lang.reflect.InvocationTargetException;
import java.util.Map;

/**
 * JavaBean：标准的Java类
 * 1、要求：
 *      1、类必须被public修饰
 *      2、必须提供空参的构造器
 *      3、成员变量必须使用private修饰
 *      4、提供公共setter和getter方法
 * 2、功能：封装数据
 *
 * 概念：
 *      成员变量：
 *      属性：setter和getter方法截取后的产物
 *          例如：getUsername()-->Username-->username
 *
 * 方法:
 *      1、setProperty()
 *      2、getProperty()
 *      3、populate()
 */
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1、设置编码
        req.setCharacterEncoding("utf-8");
        /*//2、获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        //3、封装user对象
        User loginUser = new User();
        loginUser.setUsername(username);
        loginUser.setPassword(password);
        //4、调用UserDao的login方法*/
        Map<String, String[]> map = req.getParameterMap();
        User loginUser = new User();
        try {
            BeanUtils.populate(loginUser,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        UserDao dao = new UserDao();
        User user = dao.login(loginUser);
        //5、判断user
        if (user == null){
            //登录失败
            req.getRequestDispatcher("/failServlet").forward(req,resp);
        }else {
            //登录成功
            //存储数据
            req.setAttribute("user",user);
            //转发
            req.getRequestDispatcher("/successServlet").forward(req,resp);
        }
    }

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

Druid方式的JDBC

package com.ftj.util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * JDBC工具类，使用Durid连接池
 */
public class JDBCUtil {

    private static DataSource ds;

    static {
        try {
            //1、加载配置文件
            Properties pro = new Properties();
            //使用ClassLoader加载配置文件，获取字节输入流
            String path = "jdbc.properties";
            InputStream is = JDBCUtil.class.getClassLoader().getResourceAsStream(path);
            pro.load(is);
            //2、初始化连接池对象
            ds = DruidDataSourceFactory.createDataSource(pro);
        } catch (IOException e) {
            e.printStackTrace();
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    //获取连接池对象
    public static DataSource getDataSource(){
        return ds;
    }
    //获取连接Connection对象
    public static Connection getConnection() throws SQLException {
        return ds.getConnection();
    }
}

Druid配置文件

driverClassName=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://localhost:3306/ftj?serverTimezone=UTC&characterEncoding=utf-8&useSSL=false
username=root
password=password
# 初始化连接数
initialSize=5
#最大连接数
maxActive=10
#超时时间
maxWait=3000
#报错信息意思是说：校验没有设置,将testWhileIdle修改为false不再报错，工程正常运行。
validationQuery:SELECT 1
testWhileIdle:true
testOnBorrow:false
testOnReturn:false

登录界面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/loginServlet" 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>

JavaBean测试类

package com.ftj.test;

import com.ftj.domain.User;
import org.apache.commons.beanutils.BeanUtils;
import org.junit.Test;

import java.lang.reflect.InvocationTargetException;

public class BeanUtilTest {

    @Test
    public void test(){
        User user = new User();
        try {
            //BeanUtils.setProperty(user, "username", "ftj");
            BeanUtils.setProperty(user,"hehe","male");  //操作的不是成员变量
            String hehe = BeanUtils.getProperty(user, "hehe");
            System.out.println(hehe);
        } catch (IllegalAccessException | NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        System.out.println(user);

    }
}

Druid测试类

package com.ftj.test;

import com.ftj.dao.UserDao;
import com.ftj.domain.User;
import org.junit.Test;

public class UserDaoTest {

    @Test
    public void testLogin(){
        User loginuser = new User();
        loginuser.setUsername("superbaby");
        loginuser.setPassword("123");

        UserDao dao = new UserDao();
        User user = dao.login(loginuser);
        System.out.println(user);
    }
}