java load到mysql

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

public class MySQLConnectionTest {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String user = "username";
        String password = "password";

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            System.out.println("Connected to MySQL database!");
        } catch (SQLException e) {
            System.err.println("Failed to connect to MySQL database: " + e.getMessage());
        }
    }
}

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

public class SafeSQLExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String user = "username";
        String password = "password";
        String userInput = "userInput"; // 假设这是用户输入

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            String sql = "SELECT * FROM users WHERE username = ?";
            try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
                pstmt.setString(1, userInput);
                pstmt.executeQuery();
            }
        } catch (SQLException e) {
            System.err.println("Failed to execute SQL query: " + e.getMessage());
        }
    }
}

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.List;

public class BatchInsertExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String user = "username";
        String password = "password";
        List<User> users = getUsers(); // 假设这是要插入的用户数据列表

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            String sql = "INSERT INTO users (username, email) VALUES (?, ?)";
            try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
                for (User user : users) {
                    pstmt.setString(1, user.getUsername());
                    pstmt.setString(2, user.getEmail());
                    pstmt.addBatch();
                }
                pstmt.executeBatch();
            }
        } catch (SQLException e) {
            System.err.println("Failed to execute batch insert: " + e.getMessage());
        }
    }

    private static List<User> getUsers() {
        // 获取用户数据列表的逻辑
        return List.of(new User("user1", "user1@example.com"), new User("user2", "user2@example.com"));
    }
}

class User {
    private String username;
    private String email;

    public User(String username, String email) {
        this.username = username;
        this.email = email;
    }

    public String getUsername() {
        return username;
    }

    public String getEmail() {
        return email;
    }
}