在idea中JSP+Servlet + JDBC+MySQL 注册和登录
时间: 2023-09-14 21:08:47 浏览: 23
首先,你需要在IDEA中创建一个Web项目,并添加Tomcat服务器。
接下来,你需要创建一个JSP页面来实现用户注册和登录的界面,例如:
```html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>用户登录</title>
</head>
<body>
<h1>用户登录</h1>
<form action="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>
<hr>
<h1>用户注册</h1>
<form action="register" method="post">
用户名:<input type="text" name="username"><br>
密码:<input type="password" name="password"><br>
确认密码:<input type="password" name="password2"><br>
<input type="submit" value="注册">
</form>
</body>
</html>
```
然后,你需要创建一个Servlet来处理用户的注册和登录请求。在Servlet中,你需要连接MySQL数据库,并编写相应的SQL语句来实现用户信息的查询、插入和更新操作。
例如,在doPost方法中,你可以编写以下代码:
```java
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String action = request.getServletPath();
switch (action) {
case "/login":
String username = request.getParameter("username");
String password = request.getParameter("password");
boolean success = checkUser(username, password);
if (success) {
response.sendRedirect("welcome.jsp");
} else {
response.sendRedirect("login.jsp");
}
break;
case "/register":
String username2 = request.getParameter("username");
String password2 = request.getParameter("password");
String password3 = request.getParameter("password2");
if (!password2.equals(password3)) {
response.sendRedirect("register.jsp");
} else {
boolean success2 = addUser(username2, password2);
if (success2) {
response.sendRedirect("login.jsp");
} else {
response.sendRedirect("register.jsp");
}
}
break;
default:
response.sendRedirect("login.jsp");
break;
}
}
private boolean checkUser(String username, String password) {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
boolean success = false;
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8";
conn = DriverManager.getConnection(url, "root", "123456");
String sql = "select * from users where username=? and password=?";
ps = conn.prepareStatement(sql);
ps.setString(1, username);
ps.setString(2, password);
rs = ps.executeQuery();
if (rs.next()) {
success = true;
}
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
} finally {
try {
if (rs != null) {
rs.close();
}
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return success;
}
private boolean addUser(String username, String password) {
Connection conn = null;
PreparedStatement ps = null;
boolean success = false;
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8";
conn = DriverManager.getConnection(url, "root", "123456");
String sql = "insert into users(username,password) values(?,?)";
ps = conn.prepareStatement(sql);
ps.setString(1, username);
ps.setString(2, password);
int rows = ps.executeUpdate();
if (rows > 0) {
success = true;
}
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
} finally {
try {
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return success;
}
```
在以上代码中,checkUser方法用于检查用户的登录信息是否正确,如果正确,则重定向到欢迎页面;否则,则重定向到登录页面。addUser方法用于向数据库中插入新用户的信息,如果插入成功,则重定向到登录页面;否则,则重定向到注册页面。
最后,你需要配置web.xml文件,将Servlet和JSP页面进行映射,例如:
```xml
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>com.example.LoginServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>RegisterServlet</servlet-name>
<servlet-class>com.example.RegisterServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>RegisterServlet</servlet-name>
<url-pattern>/register</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>welcome.jsp</welcome-file>
</welcome-file-list>
```
这样,你就可以在IDEA中实现JSP+Servlet + JDBC+MySQL 注册和登录的功能了。
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为了写一个基于IDEA、Java、JSP、MySQL和Tomcat的Web学生信息管理系统,你可以按照以下步骤进行:
1. 创建一个Maven项目,项目结构如下:
|--src
| |--main
| | |--java
| | | |--com.example.student
| | | | |--db // 数据库相关类
| | | | |--model // 实体类
| | | | |--servlet // Servlet类
| | | |--resources
| | | |--webapp // JSP页面和静态资源
| | |--webapp // Web资源
| |--test
| | |--java
|--pom.xml
2. 在MySQL中创建一个名为“student”的数据库,然后创建一个名为“students”的表,表结构如下:
CREATE TABLE students (
id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(50) NOT NULL,
gender VARCHAR(10) NOT NULL,
age INT NOT NULL,
major VARCHAR(50) NOT NULL,
grade INT NOT NULL
);
3. 在db包下创建一个名为“DBUtil”的工具类,用于连接数据库。代码如下:
java
package com.example.student.db;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DBUtil {
private static final String URL = "jdbc:mysql://localhost:3306/student";
private static final String USER = "root";
private static final String PASSWORD = "root";
public static Connection getConnection() {
Connection conn = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection(URL, USER, PASSWORD);
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
return conn;
}
}
4. 在model包下创建一个名为“Student”的实体类,代码如下:
java
package com.example.student.model;
public class Student {
private int id;
private String name;
private String gender;
private int age;
private String major;
private int grade;
public Student() {
}
public Student(int id, String name, String gender, int age, String major, int grade) {
this.id = id;
this.name = name;
this.gender = gender;
this.age = age;
this.major = major;
this.grade = grade;
}
// getter和setter方法省略
}
5. 在servlet包下创建一个名为“StudentServlet”的Servlet类,用于处理前端传来的请求。代码如下:
java
package com.example.student.servlet;
import com.example.student.db.DBUtil;
import com.example.student.model.Student;
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.sql.*;
import java.util.ArrayList;
import java.util.List;
@WebServlet(name = "StudentServlet", urlPatterns = "/student")
public class StudentServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String action = req.getParameter("action");
if ("add".equals(action)) {
// 处理学生信息添加请求
String name = req.getParameter("name");
String gender = req.getParameter("gender");
int age = Integer.parseInt(req.getParameter("age"));
String major = req.getParameter("major");
int grade = Integer.parseInt(req.getParameter("grade"));
Student student = new Student(0, name, gender, age, major, grade);
addStudent(student);
resp.sendRedirect(req.getContextPath() + "/student");
} else if ("edit".equals(action)) {
// 处理学生信息编辑请求
int id = Integer.parseInt(req.getParameter("id"));
String name = req.getParameter("name");
String gender = req.getParameter("gender");
int age = Integer.parseInt(req.getParameter("age"));
String major = req.getParameter("major");
int grade = Integer.parseInt(req.getParameter("grade"));
Student student = new Student(id, name, gender, age, major, grade);
updateStudent(student);
resp.sendRedirect(req.getContextPath() + "/student");
} else if ("delete".equals(action)) {
// 处理学生信息删除请求
int id = Integer.parseInt(req.getParameter("id"));
deleteStudent(id);
resp.sendRedirect(req.getContextPath() + "/student");
} else {
// 处理学生信息列表请求
List<Student> students = getAllStudents();
req.setAttribute("students", students);
req.getRequestDispatcher("/WEB-INF/views/student.jsp").forward(req, resp);
}
}
private List<Student> getAllStudents() {
List<Student> students = new ArrayList<>();
try (Connection conn = DBUtil.getConnection();
Statement stmt = conn.createStatement()) {
String sql = "SELECT * FROM students";
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
String gender = rs.getString("gender");
int age = rs.getInt("age");
String major = rs.getString("major");
int grade = rs.getInt("grade");
Student student = new Student(id, name, gender, age, major, grade);
students.add(student);
}
} catch (SQLException e) {
e.printStackTrace();
}
return students;
}
private void addStudent(Student student) {
try (Connection conn = DBUtil.getConnection();
PreparedStatement stmt = conn.prepareStatement("INSERT INTO students (name, gender, age, major, grade) VALUES (?, ?, ?, ?, ?)")) {
stmt.setString(1, student.getName());
stmt.setString(2, student.getGender());
stmt.setInt(3, student.getAge());
stmt.setString(4, student.getMajor());
stmt.setInt(5, student.getGrade());
stmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
}
private void updateStudent(Student student) {
try (Connection conn = DBUtil.getConnection();
PreparedStatement stmt = conn.prepareStatement("UPDATE students SET name=?, gender=?, age=?, major=?, grade=? WHERE id=?")) {
stmt.setString(1, student.getName());
stmt.setString(2, student.getGender());
stmt.setInt(3, student.getAge());
stmt.setString(4, student.getMajor());
stmt.setInt(5, student.getGrade());
stmt.setInt(6, student.getId());
stmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
}
private void deleteStudent(int id) {
try (Connection conn = DBUtil.getConnection();
PreparedStatement stmt = conn.prepareStatement("DELETE FROM students WHERE id=?")) {
stmt.setInt(1, id);
stmt.executeUpdate();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
6. 在webapp目录下创建一个名为“student.jsp”的JSP页面,用于显示学生信息列表和处理学生信息的添加、编辑和删除等操作。代码如下:
html
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学生信息管理系统</title>
</head>
<body>
学生信息管理系统
ID
姓名
性别
年龄
专业
年级
操作
<c:forEach items="${students}" var="student">
${student.id}
${student.name}
${student.gender}
${student.age}
${student.major}
${student.grade}
编辑
删除
</c:forEach>
添加学生信息
<form method="post" action="${pageContext.request.contextPath}/student?action=add">
<label for="name">姓名:</label>
<input type="text" id="name" name="name" required>
<label for="gender">性别:</label>
<input type="radio" id="gender" name="gender" value="男" required>男
<input type="radio" id="gender" name="gender" value="女" required>女
<label for="age">年龄:</label>
<input type="number" id="age" name="age" required>
<label for="major">专业:</label>
<input type="text" id="major" name="major" required>
<label for="grade">年级:</label>
<input type="number" id="grade" name="grade" required>
<button type="submit">添加</button>
</form>
<c:if test="${not empty param.id}">
编辑学生信息
<form method="post" action="${pageContext.request.contextPath}/student?action=edit&id=${param.id}">
<label for="name">姓名:</label>
<input type="text" id="name" name="name" value="${student.name}" required>
<label for="gender">性别:</label>
<input type="radio" id="gender" name="gender" value="男" ${student.gender=='男'?'checked':''} required>男
<input type="radio" id="gender" name="gender" value="女" ${student.gender=='女'?'checked':''} required>女
<label for="age">年龄:</label>
<input type="number" id="age" name="age" value="${student.age}" required>
<label for="major">专业:</label>
<input type="text" id="major" name="major" value="${student.major}" required>
<label for="grade">年级:</label>
<input type="number" id="grade" name="grade" value="${student.grade}" required>
<button type="submit">保存</button>
</form>
</c:if>
</body>
</html>
7. 在pom.xml文件中添加以下依赖:
xml
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.26</version>
</dependency>
</dependencies>
8. 在Tomcat中部署该项目,启动Tomcat服务,通过浏览器访问项目的根路径,即可看到学生信息管理系统的页面。
以上是一个基本的实现过程,具体实现过程中还需要根据实际情况进行相应的调整和优化。





首先,需要下载并安装MySQL数据库,然后创建一个数据库,并创建一个表格存储数据。
接下来,打开IntelliJ IDEA,创建一个Web应用程序工程。
在工程的src目录下,创建一个Java类,用于连接和操作数据库。
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DBHelper {
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT%2B8";
private static String user = "root";
private static String password = "123456";
public static Connection getConn() {
Connection conn = null;
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
}
return conn;
}
public static void closeConn(Connection conn) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
public static int executeUpdate(String sql) {
Connection conn = null;
Statement stmt = null;
int result = 0;
try {
conn = getConn();
stmt = conn.createStatement();
result = stmt.executeUpdate(sql);
} catch (SQLException e) {
e.printStackTrace();
} finally {
closeConn(conn);
}
return result;
}
public static ResultSet executeQuery(String sql) {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = getConn();
stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}
}
这个类中包含了获取数据库连接、关闭数据库连接、执行增删改查语句的方法。
接下来,创建一个Servlet的Java类,用于处理Http请求,并调用DBHelper中的方法操作数据库。
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class StudentServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public StudentServlet() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
String action = request.getParameter("action");
if ("add".equals(action)) {
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String gender = request.getParameter("gender");
String sql = "insert into student(name,age,gender) values('" + name + "'," + age + ",'" + gender + "')";
int result = DBHelper.executeUpdate(sql);
if (result > 0) {
out.print("<script>alert('添加成功');window.location.href='index.jsp';</script>");
} else {
out.print("<script>alert('添加失败');history.go(-1);</script>");
}
} else if ("delete".equals(action)) {
int id = Integer.parseInt(request.getParameter("id"));
String sql = "delete from student where id=" + id;
int result = DBHelper.executeUpdate(sql);
if (result > 0) {
out.print("<script>alert('删除成功');window.location.href='index.jsp';</script>");
} else {
out.print("<script>alert('删除失败');history.go(-1);</script>");
}
} else if ("update".equals(action)) {
int id = Integer.parseInt(request.getParameter("id"));
String name = request.getParameter("name");
int age = Integer.parseInt(request.getParameter("age"));
String gender = request.getParameter("gender");
String sql = "update student set name='" + name + "',age=" + age + ",gender='" + gender + "' where id=" + id;
int result = DBHelper.executeUpdate(sql);
if (result > 0) {
out.print("<script>alert('修改成功');window.location.href='index.jsp';</script>");
} else {
out.print("<script>alert('修改失败');history.go(-1);</script>");
}
} else if ("query".equals(action)) {
String name = request.getParameter("name");
String sql = "select id,name,age,gender from student where name like '%" + name + "%'";
ResultSet rs = DBHelper.executeQuery(sql);
StringBuilder sb = new StringBuilder("");
sb.append("编号 姓名 年龄 性别 操作 ");
try {
while (rs.next()) {
sb.append("");
sb.append("" + rs.getInt("id") + " ");
sb.append("" + rs.getString("name") + " ");
sb.append("" + rs.getInt("age") + " ");
sb.append("" + rs.getString("gender") + " ");
sb.append("修改 删除 ");
sb.append(" ");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
DBHelper.closeConn(DBHelper.getConn());
}
sb.append("");
out.print(sb.toString());
} else {
response.sendRedirect("index.jsp");
}
out.flush();
out.close();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}
这个Servlet中包含了添加学生记录、删除学生记录、修改学生记录、查询学生记录的方法。
最后,在Web应用程序中创建JSP页面,用于添加、修改、查询和展示学生信息的操作。
以查询学生信息页面query.jsp为例:
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>学生信息查询</title>
</head>
<body>
学生信息查询
<form action="StudentServlet" method="get">
姓名:<input type="text" name="name">
<input type="hidden" name="action" value="query">
<input type="submit" value="查询">
</form>
查询结果 <%= request.getAttribute("resultStr") %> </body> </html> 在这个页面中,用户可以输入学生姓名,然后点击查询按钮,调用Servlet中的查询学生记录的方法,返回查询结果并显示在页面上。 这样就完成了使用Idea连接MySQL数据库和Servlet进行增删改查操作的示例。
查询结果 <%= request.getAttribute("resultStr") %> </body> </html> 在这个页面中,用户可以输入学生姓名,然后点击查询按钮,调用Servlet中的查询学生记录的方法,返回查询结果并显示在页面上。 这样就完成了使用Idea连接MySQL数据库和Servlet进行增删改查操作的示例。




