InputStream.read(byte [],0 length)提前停止？

Question

我一直在写一些东西来读取来自传入的HttpServletRequest(下面的'request')的请求流(包含gzip压缩数据),但看起来普通的InputStream读取方法实际上并没有读取所有内容？

我的代码是:

InputStream requestStream = request.getInputStream();
if ((length = request.getContentLength()) != -1)
{
    received = new byte[length];
    requestStream.read(received, 0, length);
}
else
{
    // create a variable length list of bytes
    List<Byte> bytes = new ArrayList<Byte>();

    boolean endLoop = false;
    while (!endLoop)
    {
        // try and read the next value from the stream.. if not -1, add it to the list as a byte. if
        // it is, we've reached the end.
        int currentByte = requestStream.read();
        if (currentByte != -1)
            bytes.add((byte) currentByte);
        else
            endLoop = true;
    }
    // initialize the final byte[] to the right length and add each byte into it in the right order.
    received = new byte[bytes.size()];
    for (int i = 0; i < bytes.size(); i++)
    {
        received[i] = bytes.get(i);
    }
}

我在测试期间发现的是,有时顶部(当存在内容长度时)将停止读取传入请求流的一部分,并将"接收"字节数组的其余部分留空.如果我只是让它在任何时候都运行if语句的else部分,那么它读得很好并且所有预期的字节都放在'received'中.

所以,似乎我现在可以单独留下我的代码进行更改,但有没有人知道为什么正常的'read'(byte [],int,int)'方法停止读取？描述说如果存在文件结尾,它可能会停止.可能是因为gzip压缩的数据恰好包含匹配任何签名的字节吗？

Answer 1

您需要while在顶部添加一个循环以获取所有字节.流将尝试尽可能多地读取字节,但不需要len一次返回字节:

尝试读取len个字节,但可以读取较小的数字,可能为零.

if ((length = request.getContentLength()) != -1)
{
    received = new byte[length];
    int pos = 0;
    do {
        int read = requestStream.read(received, pos, length-pos);

        // check for end of file or error
        if (read == -1) {
            break;
        } else {
            pos += read;
        }
    } while (pos < length);
}

编辑:修复时.