如何将BufferedImage对象转换为InputStream或BLOB？

将BufferedImage对象转换为InputStream或BLOB的方法如下：

将BufferedImage对象转换为InputStream：

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;

public class BufferedImageToInputStream {
    public static InputStream convert(BufferedImage bufferedImage, String format) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ImageIO.write(bufferedImage, format, byteArrayOutputStream);
        InputStream inputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
        return inputStream;
    }
}

将BufferedImage对象转换为BLOB：

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

public class BufferedImageToBLOB {
    public static void convert(BufferedImage bufferedImage, String format, String jdbcUrl, String user, String password) throws IOException, SQLException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ImageIO.write(bufferedImage, format, byteArrayOutputStream);
        InputStream inputStream = new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
        Connection connection = DriverManager.getConnection(jdbcUrl, user, password);
        String sql = "INSERT INTO your_table_name (your_blob_column) VALUES (?)";
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        preparedStatement.setBlob(1, inputStream);
        preparedStatement.executeUpdate();
        preparedStatement.close();
        connection.close();
    }
}

其中，your_table_name和your_blob_column分别表示你要插入数据的表名和BLOB列名。

注意：在使用这些代码时，请确保已经正确配置了数据库连接信息和表结构。