package cn.com.server;
import java.io.InputStream;
public class Request {
	private InputStream input;
	private String uri;
	public Request(InputStream input){
		this.input=input;
	}
	public void parse(){
		//Read a set of characters from the socket 
		StringBuffer request=new StringBuffer(2048);
		int i;
		byte[] buffer=new byte[2048];
		try {
			i=input.read(buffer);
		}
		catch (Exception e) {
			e.printStackTrace();
			i=-1;
		}
		for (int j=0;jindex1){
				return requestString.substring(index1+1,index2);
			}
		}
		return null;
	}
	public String getUri(){
		return this.uri;
	}
}

package cn.com.server;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
/** 
 * HTTP RespOnse= Status-Line 
 *   *(( general-header | response-header | entity-header ) CRLF) 
 *   CRLF 
 *   [message-body] 
 *   Status-Line=Http-Version SP Status-Code SP Reason-Phrase CRLF 
 * 
 */
public class Response {
	private static final int BUFFER_SIZE=1024;
	Request request;
	OutputStream output;
	public Response(OutputStream output){
		this.output=output;
	}
	public void setRequest(Request request){
		this.request=request;
	}
	public void sendStaticResource()throws IOException{
		byte[] bytes=new byte[BUFFER_SIZE];
		FileInputStream fis=null;
		try {
			File file=new File(HttpServer.WEB_ROOT,request.getUri());
			if(file.exists()){
				fis=new FileInputStream(file);
				int ch=fis.read(bytes,0,BUFFER_SIZE);
				while(ch!=-1){
					output.write(bytes, 0, BUFFER_SIZE);
					ch=fis.read(bytes, 0, BUFFER_SIZE);
				}
			} else{
				//file not found 
				String errorMessage="HTTP/1.1 404 File Not Found\r\n"+ 
				        "Content-Type:text/html\r\n"+ 
				        "Content-Length:23\r\n"+ 
				        "\r\n"+ 
				        "
File Not Found
";
				output.write(errorMessage.getBytes());
			}
		}
		catch (Exception e) {
			System.out.println(e.toString());
		}
		finally{
			if(fis!=null){
				fis.close();
			}
		}
	}
}

package cn.com.server;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
public class HttpServer {
	/** 
   * WEB_ROOT is the directory where our html and other files reside. 
   * For this package,WEB_ROOT is the "webroot" directory under the 
   * working directory. 
   * the working directory is the location in the file system 
   * from where the java command was invoke. 
   */
	public static final String WEB_ROOT=System.getProperty("user.dir")+File.separator+"webroot";
	private static final String SHUTDOWN_COMMAND="/SHUTDOWN";
	private Boolean shutdown=false;
	public static void main(String[] args) {
		HttpServer server=new HttpServer();
		server.await();
	}
	public void await(){
		ServerSocket serverSocket=null;
		int port=8080;
		try {
			serverSocket=new ServerSocket(port,1,InetAddress.getByName("127.0.0.1"));
		}
		catch (Exception e) {
			e.printStackTrace();
			System.exit(0);
		}
		while(!shutdown){
			Socket socket=null;
			InputStream input=null;
			OutputStream output=null;
			try {
				socket=serverSocket.accept();
				input=socket.getInputStream();
				output=socket.getOutputStream();
				//create Request object and parse 
				Request request=new Request(input);
				request.parse();
				//create Response object 
				Response respOnse=new Response(output);
				response.setRequest(request);
				response.sendStaticResource();
			}
			catch (Exception e) {
				e.printStackTrace();
				continue;
			}
		}
	}
}

 
 
 
 
 
 
 
  
Hello World!