[java] Create a simple HTTP server with Java?

What's the easiest way to create a simple HTTP server with Java? Are there any libraries in commons to facilitate this? I only need to respond to GET/POST, and I can't use an application server.

What's the easiest way to accomplish this?

A servlet container is definitely the way to go. If Tomcat or Jetty are too heavyweight for you, consider Winstone or TTiny.

Undertow is a lightweight non-blocking embedded web server that you can get up and running very quickly.

public static void main(String[] args) {
Undertow.builder()
        .addHttpListener(8080, "localhost")
        .setHandler((exchange) -> exchange.getResponseSender().send("hello world"))
        .build().start();
}

I just added a public repo with a ready to run out of the box server using Jetty and JDBC to get your project started.

Pull from github here: https://github.com/waf04/WAF-Simple-JAVA-HTTP-MYSQL-Server.git

I'm suprised this example is'nt here:

http://hc.apache.org/httpcomponents-core-ga/httpcore/examples/org/apache/http/examples/ElementalHttpServer.java

EDIT >> The above link is not reachable. Here is an excerpt from the POST example followed by the link to the HTTP examples.

 if (!conn.isOpen()) {
        Socket socket = new Socket(host.getHostName(), host.getPort());
        conn.bind(socket);
    }
    BasicHttpEntityEnclosingRequest request = new
    BasicHttpEntityEnclosingRequest("POST",
    "/servlets-examples/servlet/RequestInfoExample");
    request.setEntity(requestBodies[i]);
    System.out.println(">> Request URI: " + request.getRequestLine().getUri());
    httpexecutor.preProcess(request, httpproc, coreContext);
    HttpResponse response = httpexecutor.execute(request, conn, coreContext);
    httpexecutor.postProcess(response, httpproc, coreContext);
    System.out.println("<< Response: " + response.getStatusLine());
    System.out.println(EntityUtils.toString(response.getEntity()));
    System.out.println("==============");
    if (!connStrategy.keepAlive(response, coreContext)) {
    conn.close();
    } else {
    System.out.println("Connection kept alive...");
    }

http://hc.apache.org/httpcomponents-core-ga/httpcore/examples/org/apache/http/examples/

I have implemented one link

N.B. for processing json, i used jackson. You can remove that also, if you need

I wrote a tutorial explaining how to write a simple HTTP server a while back in Java. Explains what the code is doing and why the server is written that way as the tutorial progresses. Might be useful http://kcd.sytes.net/articles/simple_web_server.php

Embedding Tomcat is relatively painless as such things go. Here's a good StackOverflow reference about it.

If you are using the Sun JDK you can use this built in library
Look at this site on how to use.

If n ot there are several Open Source HTTP Servers here which you can embed into your software.

This is how I would go about this:

1. Start a ServerSocket listening (probably on port 80).
2. Once you get a connection request, accept and pass to another thread/process (this leaves your ServerSocket available to keep listening and accept other connections).
3. Parse the request text (specifically, the headers where you will see if it is a GET or POST, and the parameters passed.
4. Answer with your own headers (Content-Type, etc.) and the HTML.

I find it useful to use Firebug (in Firefox) to see examples of headers. This is what you want to emulate.

Try this link: - Multithreaded Server in Java

Java 6 has a default embedded http server.

Check the thread here

By the way, if you plan to have a rest web service, here is a simple example using jersey.

The easiest is Simple there is a tutorial, no WEB-INF not Servlet API no dependencies. Just a simple lightweight HTTP server in a single JAR.

Jetty is a great way to easily embed an HTTP server. It supports it's own simple way to attach handlers and is a full J2EE app server if you need more functionality.