一个简单的http服务器(Java)

测试方法:

运行后打开IE,输入http://localhost/xxx.htm,其中xxx.htm是你放在e:\webroot\中的同名文件,

例如,在e:\webroot\目录下有clotho.htm,可以访问http://localhost/clotho.htm来浏览.

另外,如果程序不是使用默认的80端口,可以在localhost后面加端口号,

例如,代码改成HttpServer.port = 8086,可以访问http://localhost:8086/clotho.htm来浏览.

 

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
import java.net.ServerSocket;
import java.util.Date;

public class HttpServer implements Runnable {
    public static void main(String args[]) {
        HttpServer.root = "e:\\webroot\\"; // 服务器根目录
        HttpServer.port = 80; // 浏览器默认请求80端口
        HttpServer.listen();
    }

    public static void listen() {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(port);
            while (true) {
                Socket socket = serverSocket.accept();
                HttpServer server = new HttpServer(socket);
                Thread thread = new Thread(server);
                thread.start();
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            try {

            } catch (Exception ex) {
                ex.printStackTrace();
            }
        }
    }

    /**
     * 服务器根目录
     */
    public static String root;

    /**
     * 端口
     */
    public static int port;

    /**
     * 单个请求的套接字
     */
    private Socket socket;

    public HttpServer(Socket socket) {
        this.socket = socket;
    }

    public void run() {
        try {
            // 获取请求信息
            InputStream is = socket.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);

            // 生成响应数据
            String filename = getRequestFilename(br);
            String contentType = getContentType(filename);
            FileInputStream fis = new FileInputStream(root + filename);
            BufferedInputStream bis = new BufferedInputStream(fis);
            int length = bis.available();
            String respText = getResponseText(length, contentType);

            // 响应请求的浏览器
            OutputStream os = socket.getOutputStream();
            BufferedOutputStream bos = new BufferedOutputStream(os);
            bos.write(respText.getBytes()); // 返回http header信息

            byte buffer[] = new byte[length];
            bis.read(buffer, 0, length);
            bos.write(buffer); // 返回文件数据
            bos.flush();
            bos.close();

            br.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            try {
                socket.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 解析请求的页面文件名
     */
    private String getRequestFilename(BufferedReader br) {
        String filename = null;
        String line = null;
        try {
            while ((line = br.readLine()) != null) {
                if (line.startsWith("GET")) {
                    String[] segments = line.split(" ");
                    filename = segments[1];
                }
                if (line.length() == 0 || line.equals("\n")) {
                    break;
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return filename;
    }

    /**
     * ContentType属性指定响应的http内容类型
     */
    private String getContentType(String filename) {
        int pos = filename.lastIndexOf('.');
        String ext = filename.substring(pos + 1).toLowerCase();
        String contentType = null;
        switch (ext.charAt(0)) {
        case 'h': // htm html
            contentType = "text/html";
        case 'j': // jpg
            contentType = "image/jpg";
        case 'g': // gif
            contentType = "image/gif";
        default:
            contentType = "*/" + ext;
        }
        return contentType;
    }

    /**
     * 生成响应的http header信息
     */
    private String getResponseText(int length, String contentType) {
        StringBuilder sb = new StringBuilder();
        sb.append("HTTP/1.1 200 OK\n");
        sb.append("Date: " + new Date() + "\n");
        sb.append("Server: Clotho\n");
        sb.append("Accept-Ranges: bytes\n");
        sb.append("Content-Length: " + length + "\n");
        sb.append("Keep-Alive: true\n");
        sb.append("Connection: Keep-Alive\n");
        sb.append("Content-Type: " + contentType + "\n");
        sb.append("\n");
        return sb.toString();
    }
}