526互联

10.9（数据库，半成品）

发布时间 2023-10-09 22:05:46作者: 徐星凯

今天下午连接数据库，半成品

jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>

    <meta charset="UTF-8">

    <title>添加信息</title>
    <script>
        function submitButtonClick() {
            let className = document.getElementById("className").value;
            let classTeacher = document.getElementById("classTeacher").value;
            let classPlace = document.getElementById("classPlace").value;
            if (!(classTeacher=="王建民" || classTeacher=="刘立嘉"|| classTeacher=="刘丹"||
                classTeacher=="杨子光" || classTeacher=="张云霞" || classTeacher=="武勇亮" ||
                classTeacher=="高飞" || classTeacher=="孙静")) {
                alert("Teacher Error");
                return;
            }
            if (classPlace[1] !== "教") {
                alert("Addr Error");
                return;
            }
            let xmlHttp = new XMLHttpRequest();
            xmlHttp.open("POST","addInfo",false);
            xmlHttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            xmlHttp.send("className=" + className + "&classTeacher=" + classTeacher + "&classPlace=" + classPlace);
        }
    </script>
</head>
<body>
    <label for="className">课程名称:</label>
    <input type="text" id="className" name="className" required>
    <br>
    <label for="classTeacher">任课教师:</label>
    <input type="text" id="classTeacher" name="classTeacher" required>
    <br>
    <label for="classPlace">上课地点:</label>
    <input type="text" id="classPlace" name="classPlace" required><br>
    <button id="submitButton" onclick="submitButtonClick()">Go!</button>
</body>
</html>



java1



package com.example.demo;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/addInfo")
public class AddInfoServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        Connection connection = null;

        try {
            String driver = "com.mysql.cj.jdbc.Driver";
            String url = "jdbc:mysql://localhost:3306/class";
            String user = "root";
            String password = "123567";

            Class.forName(driver);
            connection = DriverManager.getConnection(url, user, password);

            if (connection != null) {
                System.out.println("数据库连接成功！");
            } else {
                System.out.println("数据库连接失败！");
            }

            String className = request.getParameter("className");
            String classTeacher = request.getParameter("classTeacher");
            String classPlace = request.getParameter("classPlace");
            System.out.println(className);
            System.out.printf(classTeacher);
            System.out.println(classPlace);
            String insertSQL = "INSERT INTO class2 (className, classTeacher, classPlace) VALUES (?, ?, ?)";
            PreparedStatement preparedStatement = connection.prepareStatement(insertSQL);
            preparedStatement.setString(1, className);
            preparedStatement.setString(2, classTeacher);
            preparedStatement.setString(3, classPlace);
            int rowsAffected = preparedStatement.executeUpdate();
            System.out.println(rowsAffected + " 行数据已插入。");
            preparedStatement.close();
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}



java2

package com.example.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DatabaseConnection {
    public static Connection getConnection() throws SQLException, ClassNotFoundException {
        String driver = "com.mysql.cj.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/class";
        String user = "root";
        String password = "123567";

        Class.forName(driver);
        return DriverManager.getConnection(url, user, password);
    }
}



 
java3

package com.example.demo;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class MySQLConnection {
    public static void main(String[] args) {
        Connection connection = null;

        try {
            String driver = "com.mysql.cj.jdbc.Driver";
            String url = "jdbc:mysql://localhost:3306/class";
            String user = "root";
            String password = "123567";

            Class.forName(driver);
            connection = DriverManager.getConnection(url, user, password);

            if (connection != null) {
                System.out.println("数据库连接成功！");
            } else {
                System.out.println("数据库连接失败！");
            }
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }

        try {
            String insertSQL = "INSERT INTO class2 (className, classTeacher,classPlace) VALUES (?, ?,?)";

            // 创建PreparedStatement对象
            PreparedStatement preparedStatement = connection.prepareStatement(insertSQL);
            preparedStatement.setString(1, "Tm"); // 设置第一个参数值
            preparedStatement.setString(2, "Tm"); // 设置第二个参数值
            preparedStatement.setString(3, "Tm"); // 设置第三个参数值
            int rowsAffected = preparedStatement.executeUpdate(); // 执行插入操作并返回受影响的行数
            System.out.println(rowsAffected + " 行数据已插入。");
            preparedStatement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (connection != null) {
                    connection.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
}