Set up HttpServer - NanoHttpd

NanoHttp is a light-weight HTTP server designed for embedding system, released under a BSD licence.

Step 1: Download .jar

NanoHttpd Github

Step 2: Import .jar

Unzip file and copy .jar file to your project/libs folder.

Step 3: Add info in build.gradle

build.gradle

android {
    ...
}

dependencies {
   ...
    compile files('libs/nanohttpd-2.3.1.jar')
}

Step 4: Create custom class

Create a custom class and extends NanoHTTPD.

NanoHttpServer.java

public class NanoHttpServer extends NanoHTTPD {
    public NanoHttpServer(int port) {
        super(port);
    }
}

Step 5: Create NanoHttpServer

Created NanoHttpServer and start http server and set up a custom port to communicate with client.

MainActivity.java

mHttpServer = new NanoHttpServer(6600);
mHttpServer.start();

Step 6: Receive message from client

When client is connected, we can receive the message and return response to client.

NanoHttpServer.java

@Override
    public Response serve(IHTTPSession session) {

        String uri = session.getUri();
        String method = session.getMethod().name();
        String remoteIp = session.getRemoteIpAddress();

        NxLog.e(TAG, "uri: " + uri);
        NxLog.e(TAG, "method: " + method);
        NxLog.e(TAG, "remoteIp: " + remoteIp);
        
        InputStream is = session.getInputStream();
        ...
        

        String msg = "Send response to client";
        return newFixedLengthResponse(msg);
    }

It should be noted that IHTTPSession.getInputStream will never return -1 as end of stream.

But we could use a buffer to control loop. When the length of reading stream less than buffer size, than we break this loop.

try {
	InputStream is = session.getInputStream();

	int buffer_szie = 1024;
	byte[] buffer = new byte[buffer_szie];
	int length = 0;
        
	do {
		length = is.read(buffer);
		//...
	} while(length >= buffer_szie );
} catch (IOException e) {
	e.printStackTrace();
}