这是一个直接用 Java 自带的 API 实现的超轻量级的 HTTP 服务器，没有使用第三方类库

import java.io.IOException;  import java.io.OutputStream;  import java.net.InetSocketAddress;  import java.util.Iterator;  import java.util.List;  import java.util.Set;  import java.util.concurrent.Executors;    import com.sun.net.httpserver.Headers;  import com.sun.net.httpserver.HttpExchange;  import com.sun.net.httpserver.HttpHandler;  import com.sun.net.httpserver.HttpServer;    public class HttpServerDemo {    public static void main(String[] args) throws IOException {      InetSocketAddress addr = new InetSocketAddress(8080);      HttpServer server = HttpServer.create(addr, 0);        server.createContext("/", new MyHandler());      server.setExecutor(Executors.newCachedThreadPool());      server.start();      System.out.println("Server is listening on port 8080" );    }  }    class MyHandler implements HttpHandler {    public void handle(HttpExchange exchange) throws IOException {      String requestMethod = exchange.getRequestMethod();      if (requestMethod.equalsIgnoreCase("GET")) {        Headers responseHeaders = exchange.getResponseHeaders();        responseHeaders.set("Content-Type", "text/plain");        exchange.sendResponseHeaders(200, 0);          OutputStream responseBody = exchange.getResponseBody();        Headers requestHeaders = exchange.getRequestHeaders();        Set<String> keySet = requestHeaders.keySet();        Iterator<String> iter = keySet.iterator();        while (iter.hasNext()) {          String key = iter.next();          List values = requestHeaders.get(key);          String s = key + " = " + values.toString() + "\n";          responseBody.write(s.getBytes());        }        responseBody.close();      }    }  }