webserver.java

用 Java 写的 web 服务器程序。

import java.io.*;
import java.net.*;
import java.util.*;
class WebServer {
    public static void main(String argv[]) throws Exception {
        String requesMessageLine;
        String fileName;
        ServerSocket listenSocket = new ServerSocket(6789);
        Socket connectionSocket = listenSocket.accept();
        BufferedReader inFromClient = 
            new BufferedReader(new InputStreamReader(
                  connectionSocket.getInputStream())); 
        DataOutputStream outToClient = 
            new DataOutputStream(
                  connectionSocket.getOutputStream());
        requesMessageLine = inFromClient.readLine();
        StringTokenizer tokenizedLine = 
            new StringTokenizer(requesMessageLine);
        if(tokenizedLine.nextToken().equals("GET")){
            fileName = tokenizedLine.nextToken();
            if(fileName.startsWith("/") == true )
                fileName = fileName.substring(1);
            File file = new File(fileName);
            int numOfBytes = (int) file.length();
            FileInputStream inFile = new FileInputStream (
                  fileName);
            byte[] fileInBytes = new byte[numOfBytes];
            inFile.read(fileInBytes);
            outToClient.writeBytes(
                   "HTTP/1.0 200 Document Follows\r\n");
            if(fileName.endsWith(".jpg"))
                outToClient.writeBytes("Content-Type: image/jpeg\r\n");
            if(fileName.endsWith(".gif"))
                outToClient.writeBytes("Content-Type: image/gif\r\n");
            outToClient.writeBytes("Content-Length: " +
                 numOfBytes + "\r\n");
            outToClient.writeBytes("\r\n");
            outToClient.write(fileInBytes, 0, numOfBytes);
            connectionSocket.close();
            }
        else System.out.println("Bad Request Message");
        }
}