Java高效整合MySQL存储图片，轻松解决图片存储难题

一、MySQL存储图片的原理

• TINYBLOB：最大长度255 bytes
• BLOB：最大长度65535 bytes（KB）
• MEDIUMBLOB：最大长度16777215 bytes（16MB）
• LONGBLOB：最大长度4GB

二、Java整合MySQL存储图片步骤

1. 创建数据库表

CREATE TABLE images (
  id INT PRIMARY KEY AUTO_INCREMENT,
  image_name VARCHAR(255),
  image_data LONGBLOB
);

2. Java代码连接MySQL数据库

使用JDBC（Java Database Connectivity）连接MySQL数据库，并获取连接对象。以下是一个示例代码：

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

public class MySQLConnection {
    public static Connection getConnection() throws SQLException {
        String url = "jdbc:mysql://localhost:3306/your_database?useSSL=false&serverTimezone=UTC";
        String user = "root";
        String password = "your_password";
        return DriverManager.getConnection(url, user, password);
    }
}

3. Java代码上传图片

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

public class ImageUploader {
    public static void uploadImage(String imagePath) throws SQLException {
        Connection conn = MySQLConnection.getConnection();
        String sql = "INSERT INTO images (image_name, image_data) VALUES (?, ?)";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        
        pstmt.setString(1, imagePath.substring(imagePath.lastIndexOf("/") + 1));
        try (InputStream in = new java.io.FileInputStream(imagePath)) {
            pstmt.setBlob(2, in);
        }
        
        pstmt.executeUpdate();
        pstmt.close();
        conn.close();
    }
}

4. Java代码读取图片

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;

public class ImageRetriever {
    public static BufferedImage getImage(int imageId) throws SQLException {
        Connection conn = MySQLConnection.getConnection();
        String sql = "SELECT image_data FROM images WHERE id = ?";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        pstmt.setInt(1, imageId);
        
        BufferedImage image = null;
        try (ResultSet rs = pstmt.executeQuery()) {
            if (rs.next()) {
                InputStream in = rs.getBinaryStream("image_data");
                image = ImageIO.read(in);
            }
        }
        
        pstmt.close();
        conn.close();
        return image;
    }
}

三、总结