2012-02-21 57 views
0

我遇到了这个问题,这个基本的,不成熟的我用Java编写的Web服务器。出于某种原因,不是仅向浏览器发送“200 OK”或“404 Not Found”,而是将它们写入正在检索的任何文件中。例如,如果我试图让index.html文件,我回到:错误返回文件w/Java Web服务器

example

....而不是浏览器试图编译HTML。 尝试获取图像时,情况会更糟糕,因为该服务器尝试向其添加“200 OK”&内容类型,该文件已损坏。任何人都可以提供任何有关如何发送状态行& content-type与实际的HTML/JPG文件分开的任何见解?当我注释掉“os.writeBytes(statusLine)”等等时,错误完全消失,但我仍然想将这些消息发送给浏览器...只是不合并文件。任何帮助将不胜感激。

import java.io.*; 
import java.net.*; 
import java.util.*; 

final class HttpRequest implements Runnable { 
    final static String CRLF = "\r\n"; 
    Socket socket; 

    // Constructor 
    public HttpRequest(Socket socket) throws Exception { 
     this.socket = socket; 
    } 

    // Implement the run() method of the Runnable interface. 
    public void run() { 
     try { 
      processRequest(); 
     } catch (Exception e) { 
      System.out.println(e); 
     } 
    } 

    private static void sendBytes(FileInputStream fis, OutputStream os) 
    throws Exception { 
    // Construct a 1K buffer to hold bytes on their way to the socket. 
    byte[] buffer = new byte[1024]; 
    int bytes = 0; 

    // Copy requested file into the socket's output stream. 
    while((bytes = fis.read(buffer)) != -1) { 
     os.write(buffer, 0, bytes); 
     } 
    } 

    private static String contentType(String fileName) { 
    if(fileName.endsWith(".htm") || fileName.endsWith(".html")) { 
     return "text/html"; 
    } 
    if(fileName.endsWith(".jpeg") || fileName.endsWith(".jpg")) { 
    return "image/jpeg"; 
    } 
    if(fileName.endsWith(".gif")) { 
    return "image/gif"; 
    } 
    return "application/octet-stream"; 
    } 

    private void processRequest() throws Exception { 
     // Get a reference to the socket's input and output streams. 
     InputStream is = socket.getInputStream(); 
     DataOutputStream os = new DataOutputStream(socket.getOutputStream()); 

     // Set up input stream filters. 
     BufferedReader br = new BufferedReader(new InputStreamReader(is)); 

     // Get the request line of the HTTP request message. 
     String requestLine = new String(br.readLine()); 

     // Display the request line. 
     System.out.println(); 
     System.out.println(requestLine); 

     // Get and display the header lines. 
     String headerLine = null; 
     while ((headerLine = br.readLine()).length() != 0) { 
      System.out.println(headerLine); 
     } 

    // Extract the filename from the request line. 
    StringTokenizer tokens = new StringTokenizer(requestLine); 
    tokens.nextToken(); // skip over the method, which should be "GET" 
    String fileName = tokens.nextToken(); 
    // Prepend a "." so that file request is within the current directory. 
    fileName = "." + fileName; 

    // Open the requested file. 
    FileInputStream fis = null; 
    boolean fileExists = true; 
    try { 
    fis = new FileInputStream(fileName); 
    } catch (FileNotFoundException e) { 
    fileExists = false; 
    } 

    // Construct the response message. 
    String statusLine = null; 
    String contentTypeLine = null; 
    String entityBody = null; 
    if (fileExists) { 
    statusLine = "200 OK" + CRLF; 
    contentTypeLine = "Content-type: " + 
     contentType(fileName) + CRLF; 
    } else { 
    statusLine = "404 NOT FOUND" + CRLF; 
    contentTypeLine = "Content Not Found!" + CRLF; 
    entityBody = "<HTML>" + 
     "<HEAD><TITLE>Not Found</TITLE></HEAD>" + 
     "<BODY>Not Found</BODY></HTML>"; 
    } 

    // Send the status line. 
    os.writeBytes(statusLine); 

    // Send the content type line. 
    os.writeBytes(contentTypeLine); 

    // Send a blank line to indicate the end of the header lines. 
    os.writeBytes(CRLF); 

    // Send the entity body. 
    if (fileExists) { 
    sendBytes(fis, os); 
    fis.close(); 
    } else { 
    os.writeBytes("File DNE: Content Not Found!"); 
    } 

     // Close streams and socket. 
     os.close(); 
     br.close(); 
     socket.close(); 
    } 
    public static void main(String[] args) throws Exception { 
     final ServerSocket ss = new ServerSocket(6789); 
     while (true) 
      new HttpRequest(ss.accept()).run(); 
    } 
} 

回答

2

我相信你错过了CRLF。是不是有一个额外的一个需要,在状态栏的末尾

200 OK 的Content-Type:XXXX

当然,你可以读取HTTP规范,或者做一个Wireshark的跟踪:)

更新:是的,你有很多问题。阅读Easy Http获取简单的 摘要。

但无论如何,你需要说“HTTP/1.0 200 OK”,例如

http://www.somehost.com/path/file.html 

首先打开一个套接字主机www.somehost.com,端口80(使用默认的80端口,因为没有在URL中指定)。然后,送东西想通过插座下面:

GET /path/file.html HTTP/1.0 
From: [email protected] 
User-Agent: HTTPTool/1.0 
[blank line here] 

服务器应具有类似下面的响应,发回通过相同的插座:

HTTP/1.0 200 OK 
Date: Fri, 31 Dec 1999 23:59:59 GMT 
Content-Type: text/html 
Content-Length: 1354 

<html> 
<body> 
<h1>Happy New Millennium!</h1> 
(more file contents) 
    . 
    . 
    . 
</body> 
</html> 
+0

我不太看到我可能错过了CRLF ...我有一个在状态线本身,以及在发送实体主体之前。你的意思是? – 2012-02-21 04:24:42

+0

请看我收录的链接。简而言之,您应该拥有HTTP/1.0 200 OK 内容类型:文本/ html 嗨!虽然有比规范更多的东西。 – MJB 2012-02-21 04:25:30

0

在状态行=“200 OK” + CRLF;

你闯到大具有正确的请求,你丢失了一些HTTP/1.1

权代码:

if (fileExists) { 
 
    statusLine = "HTTP/1.1 200 OK" + CRLF; 
 
    contentTypeLine = "Content-type: " + 
 
     contentType(fileName) + CRLF + CRLF; 
 
    } else { 
 
    statusLine = "404 NOT FOUND" + CRLF; 
 
    contentTypeLine = "Content Not Found!" + CRLF; 
 
    entityBody = "<HTML>" + 
 
     "<HEAD><TITLE>Not Found</TITLE></HEAD>" + 
 
     "<BODY>Not Found</BODY></HTML>"; 
 
    }