本帖最后由 小石姐姐 于 2018-11-1 15:21 编辑
Java tomcat 登陆案例练习
创建user类,封装用户信息
[Java] 纯文本查看 复制代码 package com.itheima.demo01;
public class User {
private int id;
private String username;
private String password;
@Override
public String toString() {
return "User{" +
"id=" + id +
", username='" + username + '\'' +
", password='" + password + '\'' +
'}';
}
public User() {
}
public User(int id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
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;
}
}
创建UserDao获得数据库信息,并对比用户信息对象user
[Java] 纯文本查看 复制代码 package com.itheima.Dao;
import com.itheima.demo01.User;
import com.itheima.util.JDBCUtils;
import org.junit.Test;
import org.springframework.dao.DataAccessException;
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(JDBCUtils.getDataSource());
/*
* 登陆方法
* 只有用户名和密码
* user包含全部用户数据,没有查询到,返回null
* */
public User login(User loninUser){
try {
String sql = "select * from user where username = ? and password =?";
User user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), loninUser.getUsername(), loninUser.getPassword());
return user;
} catch (DataAccessException e) {
e.printStackTrace();//进行日志操作
return null;
}
}
}
创建JDBC工具类型,通过调用起方法获得DataSource 对象
[Java] 纯文本查看 复制代码 package com.itheima.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
public class JDBCUtils {
//获取连接池对象
private static DataSource ds;
static {
try {
//1加载配置文件
Properties pro = new Properties();
//使用类加载器获取字节输入流
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
pro.load(is);
ds = DruidDataSourceFactory.createDataSource(pro);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
public static DataSource getDataSource(){
return ds;
}
public static Connection getconnection() throws SQLException {
return ds.getConnection();
}
}
创建Servlet文件,进行数据处理(核心文件)
[Java] 纯文本查看 复制代码 package com.itheima.domain;
import com.itheima.Dao.UserDao;
import com.itheima.demo01.User;
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 java.io.IOException;
@WebServlet("/ServletTest")
[Java] 纯文本查看 复制代码 public class ServletTest extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
String usern= request.getParameter("username");
String pass = request.getParameter("password");
//封装客户登陆信息到User对象loginuser中
User loginuser = new User();
loginuser.setUsername(usern);
loginuser.setPassword(pass);
//获取UserDao对象,调用login方法进行条件判断
UserDao userDao = new UserDao();
User user = userDao.login(loginuser);
//如果返回空,则跳转错误页面
if (user == null){
RequestDispatcher requestDispatcher = request.getRequestDispatcher("/FailServlet");
requestDispatcher.forward(request,response);
}else {
//共享数据
request.setAttribute("usershuju",user);
//转发
RequestDispatcher requestDispatcher = request.getRequestDispatcher("/SuccessServlet");
requestDispatcher.forward(request,response);
}
}
}
错误页面,数据处理
[Java] 纯文本查看 复制代码 package com.itheima.domain;
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;
@WebServlet("/FailServlet")[Java] 纯文本查看 复制代码 @WebServlet("/FailServlet")
public class FailServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//设置编码
response.setContentType("text/html;charset=utf-8");
response.getWriter().write("登陆失败,用户名或者密码错误");
}
}
正确页面处理
[Java] 纯文本查看 复制代码 package com.itheima.domain;
import com.itheima.Dao.UserDao;
import com.itheima.demo01.User;
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;
@WebServlet("/SuccessServlet")
[Java] 纯文本查看 复制代码 public class SuccessServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request,response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取共享数据
System.out.println("登陆成功");
User user =(User) request.getAttribute("usershuju");
if (user != null){
//设置编码
response.setContentType("text/html;charset=utf-8");
response.getWriter().write("登陆成功"+user.getUsername()+"欢迎您");
}
}
}
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