test request&&response 代碼實現
使用工具 IDEA 創建一個登錄頁面和後方數據庫連接
1.編寫login.html文件 導入到web文件夾下
設置配置文件 druid.properties
導入jar包 放置到web文件夾下的WEB-INF中 lib
level:Add as Library
2.創建數據庫環境
create database db1;
use db1;
create table user(
id int primary key auto_increment,
username varchar(32) unique not null,
password varchar(20) not null
)
3.創建包package domain 創建類User
public class User {
private int id;
private String username;
private String password;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUsername() {
}
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() {
"id=" + id +
", username=‘" + username + ‘\‘‘ +
", password=‘" + password + ‘\‘‘ +
‘}‘;
}
}
ALT+INS+FN快捷鍵 Getter and Setter toString()
4.創建package dao創建類Userdao 提供login()方法
UserDao.java：操作數據庫user表的類
package cn.itcast.dao;
import cn.itcast.domain.Userr;
import cn.itcast.util.JDBCUtils;
import org.springframework.dao.DataAccessException;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import java.sql.JDBCType;
/*操作數據庫中Use表的類
* */
public class Uesrdao {
//聲明JDBCTemplate對象來功用
private JdbcTemplate template=new JdbcTemplate(JDBCUtils.getDataSource());
/*登錄方法
*LoginUser只有用戶名和密碼
* return User 包括用戶全部數據,沒有查詢到，返回null值
*
*
* */
public Userr login(Userr loginUesr){
try {
//1.編寫sql
String sql = "select * from user where username=? and password=?";
//調用querry方法
Userr user = template.queryForObject(sql,
new BeanPropertyRowMapper<Userr>(Userr.class),
loginUesr.getUsername(), loginUesr.getPassword());
return user;
}
catch (DataAccessException e){
e.printStackTrace();
return null;
}
}
}
創建package util創建一個class文件 JDBCUtils
package cn.itcast.util;
import com.alibaba.druid.pool.DruidDataSource;
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的工具類，使用 Durild連接池*/
public class JDBCUtils {
private static DataSource ds;
static {
try {
//加載配置文件
Properties pro=new Properties();
//使用ClassLoader來加載配置文件，獲取字節輸入流
InputStream is=JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
pro.load(is);
//初始化連接池對象
try {
ds=DruidDataSourceFactory.createDataSource(pro);
} catch (Exception e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
}
/*獲取連接池對象*/
public static DataSource getDataSource(){
return ds;
}
/*獲取Connection對象*/
public static Connection getConnection() throws SQLException {
return ds.getConnection();
}
}
test 文件用來測試Dao
package cn.itcast.test;
import cn.itcast.dao.Uesrdao;
import cn.itcast.domain.Userr;
import org.junit.Test;
public class UserDaoTest {
@Test
public void testLogin(){
Userr loginuser=new Userr();
loginuser.setUsername("superbab");
loginuser.setPassword("123");
Uesrdao dao=new Uesrdao();
Userr user=dao.login(loginuser);
System.out.println(user);
}
}
此時輸出的結果：
此時距離成功已經很近了
我們在cn.itcast目錄下創建一個web.servlet目錄 用來存放servlet文件
loginservlet
package cn.itcast.web.servlet;
import cn.itcast.dao.Uesrdao;
import cn.itcast.domain.Userr;
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("/loginServlet")
public class loginservlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//設置編碼
req.setCharacterEncoding("utf-8");
//獲取請求參數
String username = req.getParameter("username");
String password = req.getParameter("password");
//3.封裝user對象
Userr loginuser=new Userr();
loginuser.setUsername(username);
loginuser.setPassword(password);
//調用userdao的login()
Uesrdao dao=new Uesrdao();
Userr user=dao.login(loginuser);
//5判斷user
if(user==null){
//登錄失敗
req.getRequestDispatcher("/failServlet").forward(req,resp);
}else
{
//登錄成功
//存儲數據
req.setAttribute("user",user);
//轉發
req.getRequestDispatcher("/successServlet").forward(req,resp);
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req,resp);
}
}
failservlet:
package cn.itcast.web.servlet;
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")
public class failServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//給頁面寫一句話
//設置頁面編碼
response.setContentType("text/html;charset=utf-8");
//輸出
response.getWriter().write("登錄失敗,用戶名或密碼錯誤");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
successservlet
package cn.itcast.web.servlet;
import cn.itcast.domain.Userr;
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")
public class successServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//獲取request域中
Userr user=(Userr)request.getAttribute("user");
//設置編碼
response.setContentType("text/html;charset=utf-8");
//輸出
response.getWriter().write("登錄成功!"+user.getUsername()+"歡迎您");
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
好了，我們開啟tomcat服務器 ,輸入URL 註意虛擬目錄+servlet的路徑
大功告成！
test request&&response 代碼實現