Question

我有以下代码。它的工作范围是发送第一个数据包的程度，但是一旦进入while循环，值就会变为-1，因此当循环完成一次后，dosnt循环该段代码。我试图一次将512字节的数据放入一个数据包，然后通过网络发送，但由于上述原因，这不起作用。如果有人能够指出我做错了什么并且可能建议修复，我会很高兴。

            InetAddress address = packet.getAddress();
            int port = packet.getPort();
            RRQ RRQ = new RRQ();
            int offset = 0;
            int length = 512;
            int block = 0;
            byte[] readBytes = new byte[512];
            File file = new File(filename);
            FileInputStream is = new FileInputStream(file);
            int fileBytes = is.read(readBytes, offset, length);
            DatagramPacket outPacket = RRQ.doRRQ(readBytes, block, address, port);
            socket.send(outPacket);
            System.out.println("Packet sent");
            System.out.println(fileBytes);

            byte[] outputop = new byte[2];
            outputop = outPacket.getData();
            System.out.println(outputop[0]);
            System.out.println(outputop[1]);
            System.out.println("fileBytes = " + fileBytes);

            block++;
            while (fileBytes != -1){

                socket.receive(packet);
                fileBytes = is.read(readBytes, offset, length);
                System.out.println("fileBytes = " + fileBytes);
                outPacket = RRQ.doRRQ(readBytes, block, address, port);
                outputop = outPacket.getData();
                System.out.println(outputop[0]);
                System.out.println(outputop[1]);
                socket.send(outPacket);
                System.out.println("Packet sent");
                block++;
                System.out.println(fileBytes);

            }

RRQ课程

public DatagramPacket doRRQ(byte[] data, int block, InetAddress address, int port){

int bufferOffset = 4;
int dataOffset = 0;
byte byteBlock = (byte)block++;
byte[] buffer = new byte[516];
DatagramPacket packet = new DatagramPacket(buffer, buffer.length, address, port);
buffer[0] = 0;
buffer[1] = 3;
buffer[2] = 0;
buffer[3] = byteBlock;
for(byte item:data){

    buffer[bufferOffset] = data[dataOffset];
    bufferOffset++;
    dataOffset++;

}

return packet;

Answer 1

好吧，看起来你的文件只有512字节的数据，因为在文件结束时会返回-1，如下所述：http：//docs.oracle.com/javase/6/docs/api /java/io/FileInputStream.html#read（byte []，int，int）

从文件中获取512个增量的字节并通过网络发送这些字节？

1 个答案: