how to use java with go

Question

For some reason, I have to use go as my new web project's backend language.

However, some apis we will use is written in Java and packaged in .jar file.

I am new to go, and how can I use go to cooperate with Java in a consistent way that when a HTTP request comes, the go will handle it and delegate some function to java, and then return the response.

Answer 1

What kind of API does your Java expose?

If it exposes an RPC API you could utilize Go's json-rpc module.

If it exposes a RESTful API you could utilize Go's http module.

You could also spawn a child process (your java code) and talk to it via stdin and stdout pipes. You'd use the exec module for that.

That's not an exhaustive communication list, just the first three that come to mind. You could also use an XML API, shared memory or named pipes.

Also, a message queue like 0mq might be what you're looking for. 0mq handles a lot of the tricky bits of IPC, like making senders back off sending requests if the receiver is getting overloaded, message framing, and reconnecting after failure.

There are numerous ways you could communicate between your Java code and your Go code. I think in the end it's most common and simple to do so via HTTP API. Expose a RESTful or RPC API in a Java server, run it as an HTTP API service, write your Go to handling incoming HTTP requests and then connect with the Java API from Go to assist in creating a response.