public static InputStream getFileInputStream(String filePath) throws IOException {
    // 创建OSSClient实例。
    OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);
    OSSObject ossObject = ossClient.getObject(bucketName, filePath);
    try {
	    InputStream out = ossObject.getObjectContent();
        byte[] bytes = toByteArray(out);
        return new ByteArrayInputStream(bytes);
    }finally {
        ossClient.shutdown();
    }
}

/**
* InputStream流转byte数组
*
* @param input
* @return
* @throws IOException
*/
public static byte[] toByteArray(InputStream input) throws IOException {
   ByteArrayOutputStream output = new ByteArrayOutputStream();
   byte[] buffer = new byte[input.available()];
   int n = 0;
   while (-1 != (n = input.read(buffer))) {
       output.write(buffer, 0, n);
   }
   return output.toByteArray();
}