hyperledger fabric 中的 pdf 有大小限制吗？

Question

我使用 hyperledger fabric 和 composer 创建了小型 poc。 在我的项目中，我正在上传 2 个文件， 第一次上传文件但是当我尝试上传第二个相同大小的文件时它在作曲家中显示错误

Unhandled error for request POST /api/UpdateContractDetails: Error: request entity too large at readStream (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/raw-body/index.js:196:17) at getRawBody (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/raw-body/index.js:106:12) at read (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/body-parser/lib/read.js:76:3) at jsonParser (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/body-parser/lib/types/json.js:127:5) at Layer.handle [as handle_request] (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/express/lib/router/layer.js:95:5) at trim_prefix (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/express/lib/router/index.js:317:13) at /home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/express/lib/router/index.js:284:7 at Function.process_params (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/express/lib/router/index.js:335:12) at next (/home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/express/lib/router/index.js:275:10) at /home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/loopback/server/middleware/token.js:130:7 at /home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/loopback/common/models/access-token.js:108:15 at /home/ttandale/.nvm/versions/node/v6.11.2/lib/node_modules/composer-rest-server/node_modules/loopback/common/models/access-token.js:171:11 at _combinedTickCallback (internal/process/next_tick.js:73:7) at process._tickCallback (internal/process/next_tick.js:104:9)

Answer 1

从技术上讲，这是一个 Node 问题。使用 Javascript，例如。 fs.readFileSync(‘yourimageFile.jpg’).toString(‘base64’);，您应该能够在代码中将图像转换为 Base64 字符串。您可以为您选择的（建模资产类型等）字段定义 'String' 以托管在 Hyperledger Composer 中。理论是，一旦它是一个字符串，它就会像任何其他字符串一样被发送到链代码。

这些链接可能有帮助：

-> https://www.thepolyglotdeveloper.com/2016/02/convert-an-uploaded-image-to-a-base64-string-in-node-js/

-> https://belltane.wordpress.com/2017/03/27/storing-images-in-hyperledger-fabric-blockchain/