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.

代码

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();
}
}