标准的http返回头

package socket;

import java.io.DataOutput;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

	public static void main(String[] args) {

		try {
			ServerSocket server = new ServerSocket(80);
			Socket socket = server.accept();
			DataOutputStream dou = new DataOutputStream(
					socket.getOutputStream());

			String content = "hello   welcome";
			StringBuilder bld = new StringBuilder();
			bld.append("HTTP/1.0 200 OK\r\n");
			bld.append("Last-Modified: Sat, 10 Mar 2012 14:42:12 GMT\r\n");
			bld.append("Accept-Ranges: bytes\r\n");
			bld.append("Content-Type: text/html\r\n");
			bld.append("Date: Sat, 10 Mar 2012 14:46:19 GMT\r\n");
			bld.append("Server: TestServer\r\n");
			bld.append("Expires: Sat, 10 Mar 1900 14:47:19 GMT\r\n");
			bld.append(String.format("Content-Length: %d\r\n",
					content.getBytes().length));
			bld.append("Connection: close\r\n");
			bld.append("\r\n");
			dou.write(bld.toString().getBytes());

			dou.write(content.getBytes());

		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

	}
}

之前做实验老师不能返回，原来是协议错了