Is it possible for a java web app to interact with a blockchain built with HyperLedger Composer?

Question

Or do you have to build the web application using a certain language to use composer? I've been looking this up but I'm confused how a web app would use the blockchain.

Answer 1

Yes, this is the purpose of the composer-rest-server which has a Swagger (OpenAPI) documented RESTful interface that allows one to interact with a Composer business network.

This is documented in the "Generate REST API" section of the Developer Guide .

After you create and composer deploy your .bna (business network archive) you would use the composer-rest-server command-line tool to generate and start a rest server that can interact with your business network.

Using this REST API, you can access the swagger definition source via http://localhost:3000/explorer/swagger.json . From that, you can generate a Java client using a tool such as Swagger Codegen .

Answer 2

Yes, you can do that exposing the business network as a REST API & invoking that from any web application.

See this: https://hyperledger.github.io/composer/integrating/getting-started-rest-api.html