Question

我编写了这个HttpRequest方法，但由于某种原因它总是进入404 Not Found，即使java进程没有运行时存在文件位置。

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();
    }
}

任何帮助都会非常感激...我觉得这很简单，我很想念。

Answer 1

我运行了你的代码;它工作正常（除了一些小问题，没有正确打印标题，我试过的每个浏览器都愿意完全忽略）。

您确定您的工作目录是您所期望的吗？尝试将404消息更改为：

contentTypeLine = "Content Not Found: " + new File(fileName).getAbsolutePath() + CRLF;

作为参考，我使用以下测试工具运行它：

public static void main(String[] args) throws Exception {
        final ServerSocket ss = new ServerSocket(8080);
        while (true)
            new HttpRequest(ss.accept()).run();
    }

Java中的Http请求：总是去404

1 个答案: