我正在用Java用Sockets编写程序。我可以将命令发送到客户端,也可以从客户端发送到服务器。要阅读命令,我使用BufferedReader。要编写它们,需要使用PrintWriter,但是现在我想通过套接字(不只是创建第二个连接)通过传输文件。首先,我向outputstream写入文件包含多少字节。例如40000字节。因此,我通过套接字编写了数字40000,但是连接的另一端却读取了78

所以我在想:BufferedReader读取的不仅仅是行(通过调用readLine()),这样我就从文件数据中丢失了一些字节。因为它们位于BufferedReader的缓冲区中。
因此,78数字是我要传输的文件的字节。

这种思维方式正确与否。如果是这样,如何解决这个问题。
我希望我解释得很好。

这是我的代码,但是我的默认语言是荷兰语。因此,某些变量名听起来很臭。

public void flushStreamToStream(InputStream is, OutputStream os, boolean closeIn, boolean closeOut) throws IOException {
    byte[] buffer = new byte[BUFFERSIZE];
    int bytesRead;
    if ((!closeOut) && closeIn) { // To Socket from File
        action = "Upload";
        os.write(is.available()); // Here I write 400000
        max = is.available();
        System.out.println("Bytes to send: " + max);
        while ((bytesRead = is.read(buffer)) != -1) {
            startTiming(); // Two lines to compute the speed
            os.write(buffer, 0, bytesRead);
            stopTiming(); // Speed compution
            process += bytesRead;
        }
        os.flush();
        is.close();
        return;
    }
    if ((!closeIn) && closeOut) { // To File from Socket
        action = "Download";
        int bytesToRead = -1;
        bytesToRead = is.read(); // Here he reads 78.
        System.out.println("Bytes to read: " + bytesToRead);
        max = bytesToRead;
        int nextBufferSize;
        while ((nextBufferSize = Math.min(BUFFERSIZE, bytesToRead)) > 0) {
            startTiming();
            bytesRead = is.read(buffer, 0, nextBufferSize);
            bytesToRead -= bytesRead;
            process += nextBufferSize;
            os.write(buffer, 0, bytesRead);
            stopTiming();
        }
        os.flush();
        os.close();
        return;
    }
    throw new IllegalArgumentException("The only two boolean combinations are: closeOut == false && closeIn == true AND closeOut == true && closeIn == false");
}

这是解决方案:
感谢James的建议
我认为laginimaineb anwser是解决方案的一部分。

阅读命令。
DataInputStream in = new DataInputStream(is); // Originally a BufferedReader
// Read the request line
String str;
while ((str = in.readLine()) != null) {
    if (str.trim().equals("")) {
       continue;
    }
    handleSocketInput(str);
}

现在flushStreamToStream:
public void flushStreamToStream(InputStream is, OutputStream os, boolean closeIn, boolean closeOut) throws IOException {
    byte[] buffer = new byte[BUFFERSIZE];
    int bytesRead;
    if ((!closeOut) && closeIn) { // To Socket from File
        action = "Upload";
        DataOutputStream dos = new DataOutputStream(os);
        dos.writeInt(is.available());

        max = is.available();
        System.out.println("Bytes to send: " + max);
        while ((bytesRead = is.read(buffer)) != -1) {
            startTiming();
            dos.write(buffer, 0, bytesRead);
            stopTiming();
            process += bytesRead;
        }
        os.flush();
        is.close();
        return;
    }
    if ((!closeIn) && closeOut) { // To File from Socket
        action = "Download";
        DataInputStream dis = new DataInputStream(is);
        int bytesToRead = dis.readInt();
        System.out.println("Bytes to read: " + bytesToRead);
        max = bytesToRead;
        int nextBufferSize;
        while ((nextBufferSize = Math.min(BUFFERSIZE, bytesToRead)) > 0) {
            startTiming();
            bytesRead = is.read(buffer, 0, nextBufferSize);
            bytesToRead -= bytesRead;
            process += nextBufferSize;
            os.write(buffer, 0, bytesRead);
            stopTiming();
        }
        os.flush();
        os.close();
        return;
    }
    throw new IllegalArgumentException("The only two boolean combinations are: closeOut == false && closeIn == true AND closeOut == true && closeIn == false");
}

马丁

最佳答案

DataInputStream最有可能是您要使用的。另外,不要使用available()方法,因为它通常是无用的。

09-04 05:26
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