Blob类型转换为byte数组类型

Blob类型转换成byte数组类型存储到Oracle数据库

import java.io.BufferedInputStream;
import java.io.IOException;
import java.sql.Blob;

public class BlobToBytes {
	/**
	 * 把Blob类型转换为byte数组类型
	 * 
	 * @param blob
	 * @return
	 */
	public static byte[] blobToBytes(Blob blob) {
		BufferedInputStream is = null;
		try {
			is = new BufferedInputStream(blob.getBinaryStream());
			byte[] bytes = new byte[(int) blob.length()];
			int len = bytes.length;
			int offset = 0;
			int read = 0;
			while (offset < len
					&& (read = is.read(bytes, offset, len - offset)) >= 0) {
				offset += read;
			}
			return bytes;
		} catch (Exception e) {
			return null;
		} finally {
			try {
				is.close();
				is = null;
			} catch (IOException e) {
				return null;
			}
		}
	}
}