获取提供哈希的文件

Question

我上传了一个 jar 文件并找到了它的哈希值。现在尝试通过提供哈希来下载文件。在运行上，以下代码得到的输出为：-

罐子:(blacklist.txt, [B@35f9985c)。

我们可以从输出中推断出什么。如何查看下载的文件？

 @PUT
    @Path("download_file")
    fun createIOU(
            @QueryParam("sechash") sechash: String
    ): Response {

        val SecuHash = SecureHash.parse(sechash)
        return try {
            val attachmentJr = downloadAttachment(rpcOps, SecuHash)
            println("jar      :"+attachmentJr)
            Response.status(CREATED).entity("Transaction id ${attachmentJr} committed to ledger.\n").build()
        } catch (ex: Throwable) {
            logger.error(ex.message, ex)
            Response.status(BAD_REQUEST).entity(ex.message!!).build()
        }
    }

    private fun downloadAttachment(proxy: CordaRPCOps, attachmentHash: SecureHash): Pair<String, ByteArray>? {
        //Get the attachmentJar from node for attachmentHash.
        val attachmentJar = proxy.openAttachment(attachmentHash)
        //Read the content of Jar to get file name and data.
        var file_name_data: Pair<String, ByteArray>? = null
        JarInputStream(attachmentJar).use { jar ->
            while (true) {
                val nje = jar.nextEntry ?: break
                if (nje.isDirectory) {
                    continue
                }
                file_name_data = Pair(nje.name, jar.readBytes())

            }
        }
       return file_name_data
    }

得到的输出为：

Answer 1

这是一个将附件下载为输入流的简单端点：

@GET
@Path("download-attachment")
fun downloadAttachment(@QueryParam("attachment_hash") attachmentHash: String): InputStream {
    val secureHash = SecureHash.parse(attachmentHash)
    return rpcOps.openAttachment(secureHash)
}

然后您需要将输入流作为 JAR 文件写出。这是一个简单的辅助函数：

fun downloadJar(url: String) {
    val inputStream = URL(url).openStream()

    BufferedReader(InputStreamReader(inputStream)).use {
        File("./downloaded_jar.jar").outputStream().use { outputStream ->
            inputStream.copyTo(outputStream)
        }
    }
}

获取提供哈希的文件

Get the file on giving the hash

corda