功能完整的HTTP服务器

导语

这个一个功能完备的HTTP服务器。它可以提供一个完整的文档输，包括图像，applet，HTML文件，文本文件。它与SingleFileHttpServer非常相似，只不过它所关注的是GET请求的内容。它会根据GET请求的内容在自己的工作目录查找对应的资源，并将该资源返回给用户。这个服务是相当轻量级的。

主线程代码

import java.io.File;

import java.io.IOException;

import java.net.ServerSocket;

import java.net.Socket;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.logging.Logger;

public class JHTTP {

	//开启日志

	private static final Logger logger = Logger.getLogger(JHTTP.class.getCanonicalName());

	//线程数

	private static final int NUM_THREAD = 50;

	//默认主页

	private static final String INDEX_FILE = "index.html";

	//服务器工作目录

	private final File rootDirectory;

	//端口号

	private final int port;

	/**

	 *

	 * @param _rootDirectory 工作目录

	 * @param _port	端口号

	 */

	public JHTTP(File _rootDirectory, int _port) {

		if (!_rootDirectory.isDirectory())

				throw new RuntimeException(_rootDirectory + "does not exist as a directory");

		rootDirectory = _rootDirectory;

		port = _port;

	}

	/**

	 * 启动服务器

	 * @throws IOException

	 */

	public void start() throws IOException {

		ExecutorService pool = Executors.newFixedThreadPool(NUM_THREAD);

		try (ServerSocket server = new ServerSocket(port)) {

			logger.info("Accepting connection on port" + server.getLocalPort());

			logger.info("Document Root: " + rootDirectory);

			while (true) {

				try {

					Socket request = server.accept();

					pool.execute(new RequestProcessor(rootDirectory, INDEX_FILE, request));

				} catch (IOException e) {

					logger.warning("Error accepting connection");

				}

			}

		}

	}

	public static void main(String[] args) {

		//设置工作目录

		File docroot;

		try {

			docroot = new File(args[0]);

		} catch (ArrayIndexOutOfBoundsException e) {

			System.out.println("Usage: java JHTTP docroot port");

			return;

		}

		//设置监听端口号

		int port;

		try {

			port = Integer.parseInt(args[1]);

			if (port < 0 || port > 65535) port = 8080;

		} catch (RuntimeException e) {

			port = 8080;

		}

		try {

			JHTTP webserver = new JHTTP(docroot, port);

			webserver.start();

		} catch (IOException e) {

			logger.severe("Server cloud not start");

		}

	}

}

主线程代码比较简单，默认监听8080端口，将连接提交给工作线程来处理。

处理线程

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.Writer;

import java.net.Socket;

import java.net.URLConnection;

import java.nio.file.Files;

import java.util.Date;

import java.util.logging.Logger;

public class RequestProcessor implements Runnable {

	private final static Logger logger = Logger.getLogger(RequestProcessor.class.getCanonicalName());

	private File rootDirectory;

	private String indexFileName = "index.html";

	private Socket conn;

	public RequestProcessor(File _rootDirectory, String _indexFileName,

			Socket _conn) {

		if (_rootDirectory.isFile())

			throw new IllegalArgumentException("rootDirectory muse be a directory, not a file");

		rootDirectory = _rootDirectory;

		indexFileName = _indexFileName;

		conn = _conn;

	}

	@Override

	public void run() {

		String root = rootDirectory.getPath();

		try {

			BufferedOutputStream raw = new BufferedOutputStream(conn.getOutputStream());

			Writer out = new BufferedWriter(new OutputStreamWriter(raw, "utf-8"));

			BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));

			String get = in.readLine();

			if (get != null) {

				logger.info(conn.getRemoteSocketAddress() + " " + get);

				String[] pieces = get.split("\\s+");

				String method = pieces[0];

				String version = "";

				if (method.equals("GET")) {

					String fileName = pieces[1];

					if (fileName.endsWith("/")) fileName += indexFileName;

					String contentType = URLConnection.getFileNameMap().getContentTypeFor(root +fileName);

					if (pieces.length > 2) {

						version = pieces[2];

					}

					File theFile = new File(rootDirectory, fileName.substring(1, fileName.length()));

					if (theFile.canRead() && theFile.getCanonicalPath().startsWith(root)) {

						byte[] theData = Files.readAllBytes(theFile.toPath());

						if (version.startsWith("HTTP/"))

							sendHeader(out, "HTTP/1.1 200 OK", contentType, theData.length);

						raw.write(theData);

						raw.flush();

						raw.close();

					} else { //无法找到文件

						String body = "<html><head><title>File not found</title></head><body>Error 404:文件未找到</body></html>";

						if (version.startsWith("HTTP/"))

							sendHeader(out, "HTTP/1.1 4O4 File Not Found", "text/html;charset=utf-8", body.getBytes("utf-8").length);

						out.write(body);

						out.flush();

						out.close();

					}

				} else {

					String body = "<html><head><title>File not found</title></head><body>Error 501:无法处理该请求</body></html>";

					if (version.startsWith("HTTP/"))

						sendHeader(out, "HTTP/1.1 5O1 Not Implemented", "text/html;charset=utf-8", body.getBytes("utf-8").length);

					out.write(body);

					out.flush();

					out.close();

				}

			}

		} catch (IOException e){

			logger.warning("Error talking to " + conn.getRemoteSocketAddress());

		} finally {

			try {

				conn.close();

			} catch (IOException e) {}

		}

	}

	private void sendHeader(Writer out, String responseCode, String contentType, int length) throws IOException {

		out.write(responseCode + "\r\n");

		out.write("Date: " + new Date() + "\r\n");

		out.write("Server: JHTTP 2.0\r\n");

		out.write("Content-Type: " + contentType + "\r\n");

		out.write("Content-Length: " + length + "\r\n\r\n");

		out.flush();

	}

}

在处理线程中处理客户端的请求，通过解析GET请求的资源从本地中查找对应的资源。如果没有找的则返回404错误