流程说明:
1、用户填写用户名密码,提交到LoginServlet
2、在LoginServlet使用MyBatis查询数据库,验证用户名密码是否正确
3、如果正确,响应“登录成功,如果错误,响应“登录失败””
准备环境:
1、编写静态页面到项目的webapp目录下
login.html代码:
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>login</title> <link href="css/login.css" rel="stylesheet"> </head> <body> <div id="loginDiv"> <form action="/Webapp/loginServlet" method="post" id="form"> <h1 id="loginMsg">LOGIN IN</h1> <p>Username:<input id="username" name="username" type="text"></p> <p>Password:<input id="password" name="password" type="password"></p> <div id="subDiv"> <input type="submit" class="button" value="login up"> <input type="reset" class="button" value="reset"> <a href="register.html">没有账号?点击注册</a> </div> </form> </div> </body> </html>
login.html对应的login.css代码:
* { margin: 0; padding: 0; } html { height: 100%; width: 100%; overflow: hidden; margin: 0; padding: 0; background: url(../imgs/Desert.jpg) no-repeat 0px 0px; background-repeat: no-repeat; background-size: 100% 100%; -moz-background-size: 100% 100%; } body { display: flex; align-items: center; justify-content: center; height: 100%; } #loginDiv { width: 37%; display: flex; justify-content: center; align-items: center; height: 300px; background-color: rgba(75, 81, 95, 0.3); box-shadow: 7px 7px 17px rgba(52, 56, 66, 0.5); border-radius: 5px; } #name_trip { margin-left: 50px; color: red; } p { margin-top: 30px; margin-left: 20px; color: azure; } input { margin-left: 15px; border-radius: 5px; border-style: hidden; height: 30px; width: 140px; background-color: rgba(216, 191, 216, 0.5); outline: none; color: #f0edf3; padding-left: 10px; } #username{ width: 200px; } #password{ width: 202px; } .button { border-color: cornsilk; background-color: rgba(100, 149, 237, .7); color: aliceblue; border-style: hidden; border-radius: 5px; width: 100px; height: 31px; font-size: 16px; } #subDiv { text-align: center; margin-top: 30px; } #loginMsg{ text-align: center;color: aliceblue; }
2、创建db1数据库,创建tb_user表,创建User实体类
创建db1数据库,创建tb_user表
实体类代码:
public class User { private Integer id; private String username; private String password; public Integer getId() { return id; } public void setId(Integer 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; } @Override public String toString() { return "User{" + "id=" + id + ", username='" + username + '\'' + ", password='" + password + '\'' + '}'; } }
3、导入MyBatis坐标,MySQL驱动坐标
pom.xml文件:
<?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>Webapp</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <properties> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.34</version> </dependency> </dependencies> <build> <plugins> <!-- tomcat 插件--> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.2</version> </plugin> </plugins> </build> </project>
4、创建mysqls-config.xml核心配置文件,UserMapper.xml映射文件,UserMapper接口
mysqls-config.xml核心配置文件:
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!----> <typeAliases> <package name="com.itheima.pojo"/> </typeAliases> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql:///db1?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai"/> <property name="username" value="数据库用户名"/> <property name="password" value="数据库密码"/> </dataSource> </environment> </environments> <mappers> <!--扫描mapper--> <package name="com.itheima.mapper"/> </mappers> </configuration>
UserMapper.xml映射文件:
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="com.itheima.mapper.UserMapper"> </mapper>
UserMapper接口:
import com.itheima.pojo.User; import org.apache.ibatis.annotations.Param; import org.apache.ibatis.annotations.Select; public interface UserMapper { /** * 根据用户名和密码查询用户对象 * @param username * @param password * @return */ @Select("select * from tb_user where username = #{username} and password = #{password}") User select(@Param("username") String username, @Param("password") String password); }
编写loginServlet代码用于生成连接数据:
import com.itheima.mapper.UserMapper; import com.itheima.pojo.User; import org.apache.ibatis.io.Resources; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; import javax.servlet.*; import javax.servlet.http.*; import javax.servlet.annotation.*; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; @WebServlet("/loginServlet") public class LoginServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1、用户名和密码 String username = request.getParameter("username"); String password = request.getParameter("password"); //2、调用MyBatis完成查询 //2.1 获取SqlSessionFactory对象 String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); //2.2 获取SqlSession对象 SqlSession sqlSession = sqlSessionFactory.openSession(); //2.3 获取Mapper UserMapper userMapper = sqlSession.getMapper(UserMapper.class); //2.4 使用方法 User user = userMapper.select(username, password); //2.5 释放资源 sqlSession.close(); response.setContentType("text/html;charset=utf-8"); PrintWriter writer = response.getWriter(); //3 判断user释放null if(user != null){ // 登陆成功 writer.write("登录成功"); } else { // 登陆失败 writer.write("登录失败"); } } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }
执行结果:
登录成功显示: