java.lang.NullPointerException：null地址||空缓冲区

Question

我正在使用java中的VOIP应用程序。我尝试将我的代码从多个套接字修改为只有一个，我得到以下错误： run error

我有一个主要课程，我在哪里运行发送者和接收者。

提到的那一行是：

  

sending_socket.send（AP）;

代码如下：

package DatagramSocket2Mitigated;

/*
* TextSender.java
*/
/**
*
* @author abj
*/
import CMPC3M06.AudioRecorder;
import java.net.*;
import java.io.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.sound.sampled.LineUnavailableException;
import uk.ac.uea.cmp.voip.DatagramSocket2;

public class SenderThread implements Runnable {

DatagramSocket2 sending_socket;
AudioRecorder recorder;
private int headerSize;
private int pID;
private int bufferIndex;
private final int bufferSize;
DatagramPacket[] sendingBuffer;

public SenderThread(int bufferSize, int headerSize)
        throws LineUnavailableException {
    pID = 0;
    bufferIndex = 0;
    this.bufferSize = bufferSize;
    this.headerSize = headerSize;
    sendingBuffer = new DatagramPacket[bufferSize];

}

public void start() {
    Thread thread = new Thread(this);
    thread.start();
}

public void run() {

    //***************************************************
    //Port to send to
    int PORT = 55555;
    //IP ADDRESS to send to
    InetAddress clientIP = null;
    try {
        clientIP = InetAddress.getByName("localhost");  //CHANGE localhost to IP or NAME of client machine
    } catch (UnknownHostException e) {
        System.out.println("ERROR: TextSender: Could not find client IP");
        e.printStackTrace();
        System.exit(0);
    }
    //***************************************************

    //***************************************************
    //Open a socket to send from
    //We dont need to know its port number as we never send anything to it.
    //We need the try and catch block to make sure no errors occur.
    //DatagramSocket sending_socket;
    try {
        recorder = new AudioRecorder();
        sending_socket = new DatagramSocket2();
    } catch (SocketException e) {
        System.out.println("ERROR: TextSender: Could not open UDP socket to send from.");
        e.printStackTrace();
        System.exit(0);
    } catch (LineUnavailableException ex) {
        Logger.getLogger(SenderThread.class.getName()).log(Level.SEVERE, null, ex);
    }

    //Main loop.
    boolean running = true;
    DatagramPacket packet;
    byte[] block;

    while (!Thread.interrupted()) {
        try {

            block = recorder.getBlock();

            packet = addHeader(block);

            sendingBuffer[interleave(bufferIndex)] = packet;

            // Increment packet id and the buffer index
            pID++;
            bufferIndex++;

            // Send packets if buffer is full
            if (bufferIndex >= bufferSize) {
                for (DatagramPacket ap : sendingBuffer) {
                    sending_socket.send(ap);
                }
                // Reset the buffer
                sendingBuffer = new DatagramPacket[bufferSize];
                bufferIndex = 0;
            }

            //Make a DatagramPacket from it, with client address and port number
            //DatagramPacket packet = new DatagramPacket(block, block.length, clientIP, PORT);
            //Send it
            // sending_socket.send(packet);
        } catch (IOException e) {
            System.out.println("ERROR: TextSender: Some random IO error occured!");
            e.printStackTrace();
        }
    }
    recorder.close();
    //Close the socket
    sending_socket.close();
    //***************************************************
}

/**
 *
 * @param audioBlock
 * @return
 * @throws IOException
 */
public DatagramPacket addHeader(byte[] audioBlock) throws IOException {
    byte[] sendingBlock = new byte[audioBlock.length + headerSize];

    sendingBlock[0] = (byte) this.pID;
    sendingBlock[1] = (byte) (((this.pID) >> 8) & 0xFF);
    sendingBlock[2] = (byte) (((this.pID) >> 16) & 0xFF);
    sendingBlock[3] = (byte) (((this.pID) >> 24) & 0xFF);

    // Add packetID to block 
    //sendingBlock[0] = (byte)pID;
    System.arraycopy(audioBlock, 0, sendingBlock, headerSize, audioBlock.length);

    // Create datagram packet
    return new DatagramPacket(sendingBlock, sendingBlock.length);

}

public int interleave(int pNo) {
    // size 2 interleaver
    int size = 2;
    return ((pNo % size) * size) + (pNo / size);
}

}

问题是当我测试多个套接字时代码有效。我只删除了一些确定套接字的if语句。