HTTP服务器(3)

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