DatagramSocket总是发送UDP数据后无法接收数据

ref:http://blog.chinaunix.net/uid-20771867-id-3416509.html
cmd：telnet localhost 5554
redir add udp:8002:8001 (将PC 8002端口映射为模拟器 8001端口)
模拟器-SERVER：ServerSocket server = new ServerSocket(8001);//zcl:7100改为2888
public static void ReceiveUDP() throws IOException {
// TODO Auto-generated method stub
ReliableUDP udp = new ReliableUDP(null, "172.17.21.231", 8001, 8001);
byte[] revBuf = new byte[1024];
int res = udp.ReadFixedLength(revBuf, 1);
}
PC-CLIENT：Socket socket = new Socket("127.0.0.1", 8002);
《TCP/UDP测试工具》 UDP:127.0.0.1 port 8002 (注意：8002是PC的映射端口)

ok ——》 最终找到原因：是redir add会抢占端口:
ok ——》解决方法：环境设置——关键是一定要使用remotePC，单靠本机无法实现调试

+++++++++++++++++++++++++++++++++++++++++          +++++++++++++++++++++++++++++++++++++++++
+    localPC                            +          +          remotePC                     +
+    ip:172.17.22.8                     +          +        ip:172.17.21.54                +
+     redir udp:8002:8001               +          +                                       +
+                                       +          +                                       +
+   +++++++++++++++++++++++++++++       +          +                                       +
+   + android vm                +       +          +                                       +
+   +                           +       +          +                                       +
+   +                           +       +          +                                       +
+   +  send(DestIP=remotePC,    +       +          +         Receive(localPort=8001)       +
+   +       localPort=8001)     +       +          +                                       +
+   +       DestPort=8001)      +       +          +                                       +
+   +       -----8001--------------------------------->  8001                              -
+   +                           +       +          +                                       +
+   +                           +       +          +                                       +
+   +  Receive(localPort=8001), +       +          +        send(  DestIP=localPC          +
+   +                           +       +          +                localPort=8001)        +
+   +                           +       +          +                DestPort=8002)         +
+   +                           +       +          +                                       +
+   +            8001<----------+---8002<----------+-----8001                              +
+   +                           +       +          +                                       +
+   +                           +       +          +                                       +
+   +++++++++++++++++++++++++++++       +          +                                       +
+                                       +          +                                       +
+++++++++++++++++++++++++++++++++++++++++          +++++++++++++++++++++++++++++++++++++++++

ok ——》code：
public class LEDControlerDriver {
public static void SendUDP() {
// TODO Auto-generated method stub
ReliableUDP udp = new ReliableUDP(null, DestIP, 8001, 8001);//to lydsw 前一个8001是模拟器-SERVER port，后一个8001是pc 接收消息的port，注意！不是pc映射给模拟器的端口(8002)
String s= "32323213";
int res = udp.SendFixedLength(s.getBytes(), s.length());

}

public static void ReceiveUDP() throws IOException {
// TODO Auto-generated method stub
ReliableUDP udp = new ReliableUDP(null, DestIP, 8001, 8001);//to lydsw 前一个8001是模拟器-SERVER port，后一个8001是pc 接收消息的port，注意！不是pc映射给模拟器的端口(8002)
byte[] revBuf = new byte[1];
int res = udp.ReadFixedLength(revBuf, 1);
}

public class ReliableUDP {
public int SendFixedLength(byte[] sendBuf,int nSendLen){
Log.i("UDP Demo", "发送数据(1):");
// check
int res = 1;
if (sendBuf.length!=nSendLen) {
return -2;
}

// create socket
DatagramSocket socket = null;
try {
socket = new DatagramSocket(null); // 指定Null很重要，否则Java会自动随机选个可用端口来绑定
socket.setReuseAddress(true); // DatagramSocket的setReuseAddress(true)方法执行后，可以允许多个DatagramSocket
// 绑定到相同的IP地址和端口，那么发送到此IP地址和端口的数据能够被复制到多个DatagramSocket
socket.setSoTimeout(10000);
socket.bind(new InetSocketAddress(this.LocalPort));
} catch (SocketException e) {
Log.i("UDP Demo", "SendFixedLength:socket create failed1:"+e.getMessage());
return -3;
}

Log.i("UDP Demo", "发送数据(2):");
// 定义一个用于发送的DatagramPacket对象
DatagramPacket outPacket = null;
try {
outPacket = new DatagramPacket(sendBuf , nSendLen , InetAddress.getByName(this.IPaddr) , this.TargetPort);
socket.send(outPacket);
Log.i("UDP Demo", "SendData:UDP发送数据:"+StringHexbyteTransform.bytesToHexString(sendBuf));
} catch (IOException e2) {
Log.i("UDP Demo", "SendData:io failed:"+e2.toString()+":"+e2.getMessage());
res = -52;
}

socket.close();
return res;
}

public int ReadFixedLength(byte[] revBuf,int nRecvLen, int timeout)
{
Log.i("UDP Demo", "Read数据(1):");
// check
int res = 1;
int len = nRecvLen;
if (-1 == nRecvLen) {
len = revBuf.length;
}

// create socket
DatagramSocket socket = null;
try {
socket = new DatagramSocket(null); // 指定Null很重要，否则Java会自动随机选个可用端口来绑定
socket.setReuseAddress(true); // DatagramSocket的setReuseAddress(true)方法执行后，可以允许多个DatagramSocket
// 绑定到相同的IP地址和端口，那么发送到此IP地址和端口的数据能够被复制到多个DatagramSocket
socket.setSoTimeout(timeout);
socket.bind(new InetSocketAddress(this.LocalPort));
} catch (SocketException e) {
Log.i("UDP Demo", "SendFixedLength:socket create failed1:"+e.getMessage());
return -3;
}

Log.i("UDP Demo", "Read数据(2):");
// 定义一个用于发送的DatagramPacket对象
DatagramPacket inPacket = null;
try {
inPacket = new DatagramPacket(revBuf , len);
socket.receive(inPacket);
ExpandRevBuffer(revBuf);
Log.i("UDP Demo", "receive:"+StringHexbyteTransform.bytesToHexString(revBuf));
} catch (IOException e2) {
Log.i("UDP Demo", "SendData:io failed:"+e2.toString()+":"+e2.getMessage());
res = -52;
}

socket.close();
return res;
}