Android与PC的Socket（TCP/IP）通信(by USB) 拒绝连接的问题
情形一：
Android_Server：
final int SERVER_PORT = 12345;
private void startServer()
{
try
{
Log.e("s: connecting...", "");
ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
while (true)
{
Socket client = serverSocket.accept();
Log.e("s: receiving...", "jjjjjj");
try
{
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
String str = in.readLine();
Log.e("s: received:'" , "%%%%%%" + str);
}
catch (Exception e)
{
Log.e("s: error", "");
e.printStackTrace();
}
finally
{
client.close();
Log.e("s:done", "");
}
Thread.sleep(3000);
}
}
catch (Exception e)
{
Log.e("s:error", "");
e.printStackTrace();
}
}

PC_Client:
try
{
Runtime.getRuntime().exec("adb forward tcp:12581 tcp:12345");
}
catch (IOException e3)
{
e3.printStackTrace();
}

Socket socket = null;
try
{
InetAddress serverAddr = null;
serverAddr = InetAddress.getByName("127.0.0.1");
System.out.println("TCP 1111" + "C: Connecting...");

socket = new Socket(serverAddr, 12581);//此处的12581是PC开放的端口，已重定向到Device的12345端口

String message = "AndroidRes,Where is my Pig (Android)?";
System.out.println("TCP 2222" + "C: Sending: '" + message + "'");
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),

true);
out.println(message);
}
catch (UnknownHostException e1)
{
System.out.println("TCP 3333" + "ERROR:" + e1.toString());
}
catch (IOException e2)
{
System.out.println("TCP 4444" + "ERROR:" + e2.toString());
}
finally
{
try
{
if (socket != null)
{
socket.close();
}
}
catch (IOException e)
{
System.out.println("TCP 5555" + "ERROR:" + e.toString());
}
}
}
Android_Server与PC_Client连接成功~

情形二：
PC_Server:
try
{
Runtime.getRuntime().exec("adb forward tcp:12555 tcp:12345");

System.out.println("s: connecting...");
ServerSocket serverSocket = new ServerSocket(SERVER_PORT);

while (true)
{
Socket client = serverSocket.accept();
System.out.println("s: receiving...");
try
{
BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
String str = in.readLine();
System.out.println("s: received:'" + str + "'");
}
catch (Exception e)
{
System.out.println("s: error");
e.printStackTrace();
}
finally
{
client.close();
System.out.println("s:done");
}
}
}
catch (Exception e)
{
System.out.println("s:error");
e.printStackTrace();
}
Android_Client:
Socket socket = null;
try
{
InetAddress serverAddr = null;
serverAddr = InetAddress.getByName("127.0.0.1");
Log.e("TCP 1111", "C: Connecting...");

socket = new Socket(serverAddr, 12345);

String message = "AndroidRes,Where is my Pig (Android)?";
Log.e("TCP 2222", "C: Sending: '" + message + "'");
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),

true);
out.println(message);
}
catch (UnknownHostException e1)
{
Log.e("TCP 3333", "ERROR:" + e1.toString());
}
catch (IOException e2)
{
Log.e("TCP 4444", "ERROR:" + e2.toString());
}
finally
{
try
{
if (socket != null)
{
socket.close();
}
}
catch (IOException e)
{
Log.e("TCP 5555", "ERROR:" + e.toString());
}
}
Android_Client与PC_Server连接失败~抛出以下异常：
E/TCP 1111(12986): C: Connecting...
E/TCP 4444(12986): ERROR:java.net.ConnectException: /127.0.0.1:12345 - Connection refused

我的问题是：
1、Android与PC通信时，是否Android端只能做Server？
2、若Android可以做Client端，要怎么实现，以上代码哪儿有问题？
3、有更多相关的知识也请附上共享，谢谢~~

[解决办法]
我也是搜出来的：现贴下完整点的：

问题是这样的，android模拟器（simulator）把它自己作为了localhost,也就是说，代码中使用

localhost或者127.0.0.1来访问，都是访问模拟器自己！这是不行的！

如果你想在模拟器上面访问你的电脑，那么就使用android内置的IP 10.0.2.2 吧， 10.0.2.2 是模拟器设置的特定ip，是你的电脑的别名alias

在模拟器上用10.0.2.2访问你的电脑本机

参考网址：http://80x86.javaeye.com/blog/539356