JREに同梱のcom.sun.net.httpserverを使ってHTTPのテストをする方法 ref: http://qiita.com/items/92a7d6d530d6221d407f

MyTests.java

import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import static org.junit.Assert.*;

import org.junit.Test;
import com.sun.net.httpserver.*;

public class MyTests {
        @Test
        public void httpServer_API_test() throws Exception {
              HttpServer httpServer = HttpServer. create( new InetSocketAddress("localhost" ,8080),8080);
              ExecutorService httpThreadPool = Executors. newFixedThreadPool(1);
              httpServer.setExecutor(httpThreadPool);
              httpServer.createContext( "/" ,new HttpHandler(){
                      @Override
                      public void handle(HttpExchange exc) throws IOException {
                           final String response = "Hello HTTP Server" ;
                           exc.sendResponseHeaders(200, response.length());
                           OutputStream os = exc.getResponseBody();
                           os.write(response.getBytes());
                      os.close();
                     }
              });
              httpServer.start();
               // なんやらかんやらテスト
              httpServer.stop(1);
              httpThreadPool.shutdownNow();
       }
}