JDBC实现图片的上传与读取

最新推荐文章于 2023-01-02 17:26:27 发布

原创最新推荐文章于 2023-01-02 17:26:27 发布 · 987 阅读

4 ·

CC 4.0 BY-SA版权

文章标签：

#jdbc #java #mysql #数据库

本文详细介绍了使用Java和MySQL数据库进行图片数据的存储与读取过程。通过PreparedStatement预处理语句，实现图片文件的二进制流上传至数据库，并演示了如何从数据库中检索图片数据并保存到本地。

上传图片

	public void GetConnectionTest() throws SQLException, FileNotFoundException {
		//定义url
		String url = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT";
		//创建Driver驱动
		Driver driver = new com.mysql.cj.jdbc.Driver();
		//通过驱动获取链接
		Properties pro = new Properties();
		pro.setProperty("user", "root");
		pro.setProperty("password", "123456");
		Connection conn = driver.connect(url, pro);
		
		String sql = "insert into test1 (t_id,t_image) value (?,?)";
		PreparedStatement pstmt = conn.prepareStatement(sql);
		
		pstmt.setInt(1, 1);
		
		InputStream in = new FileInputStream(new File("src/123.jpg"));
		pstmt.setBlob(2, in);
		
		//执行
		pstmt.executeUpdate();
		
		//释放资源
		JDBCUtil.releaseSource(null, pstmt, conn);
	}

读取

	public void queryBlob() throws SQLException, IOException {
		//定义url
		String url = "jdbc:mysql://localhost:3306/test?serverTimezone=GMT";
		//创建Driver驱动
		Driver driver = new com.mysql.cj.jdbc.Driver();
		//通过驱动获取链接
		Properties pro = new Properties();
		pro.setProperty("user", "root");
		pro.setProperty("password", "123456");
		Connection conn = driver.connect(url, pro);
		
		
		String sql = "select t_image from test1 where t_id=?";
		//获取执行对象
		PreparedStatement pstmt = conn.prepareStatement(sql);
		//设置参数
		pstmt.setInt(1, 1);
		//执行sql
		ResultSet rs = pstmt.executeQuery();
		while(rs.next()) {
			Blob photo = rs.getBlob("t_image");
			InputStream in = photo.getBinaryStream();
			OutputStream out = new FileOutputStream(new File("src/1233.jpg"));
			byte[] buf = new byte[1024];
			int len =0;
			while((len = in.read(buf))!= -1) {
				out.write(buf, 0, len);
			}
			in.close();
			out.close();
		}
		
		//释放资源
		JDBCUtil.releaseSource(rs, pstmt, conn);	
	}

注：此处用的是PreparedStatement进行的预处理