Java如何将BLOB数据存储到数据库中？
数据库BLOB（二进制大对象）可用于存储任何数据，例如可以是图像，音频或视频文件。本示例说明如何使用JDBC库将图像存储在数据库中。要将二进制信息发送到数据库，我们可以调用该PreparedStatement.setBinaryStream()方法并传递适当的输入流及其大小。
package org.nhooo.example.jdbc;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
public class BlobDemo {
private static final String URL = "jdbc:mysql://localhost/nhooo";
private static final String USERNAME = "root";
private static final String PASSWORD = "";
public static void main(String[] args) {
try (Connection conn =
DriverManager.getConnection(URL, USERNAME, PASSWORD)) {
conn.setAutoCommit(false);
String sql = "INSERT INTO product_images " +
"(product_id, name, description, image) VALUES (?, ?, ?, ?)";
String image = "/uml-distilled-3rd-edition.jpg";
try (PreparedStatement stmt = conn.prepareStatement(sql);
InputStream is = BlobDemo.class.getResourceAsStream(image)) {
stmt.setLong(1, 1L);
stmt.setString(2, "uml-distilled-3rd-edition.jpg");
stmt.setString(3, "UML Distilled 3rd Edition");
stmt.setBinaryStream(4, is);
stmt.execute();
conn.commit();
} catch (Exception e) {
conn.rollback();
e.printStackTrace();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}product_images表的结构。
CREATE TABLE `product_images` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `product_id` bigint(20) unsigned NOT NULL, `name` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL, `description` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL, `image` blob, PRIMARY KEY (`id`), KEY `product_id` (`product_id`), CONSTRAINT `product_images_ibfk_1` FOREIGN KEY (`product_id`) REFERENCES `products` (`id`) ) ENGINE=InnoDB;
Maven依赖
<!-- https://search.maven.org/remotecontent?filepath=mysql/mysql-connector-java/8.0.17/mysql-connector-java-8.0.17.jar -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.17</version>
</dependency>