我在尝试为Android实现服务器/客户端应用程序时遇到了问题。
我实现了一个服务器类，我首先通过构造函数初始化，然后启动一个异步任务来运行它。
这是服务器类：
public class Server {
RestaurantTables activity;
ServerSocket serverSocket;
String message = "";
Handler updateConversationHandler;
//static final int socketServerPORT = 8080;
static final int socketServerPORT = 0; // 0 = take any free port
public Server(RestaurantTables activity) {
this.activity = activity;
//Thread socketServerThread = new Thread(new SocketServerThread(this.activity.getHandler()));
updateConversationHandler = new Handler();
map = new HashMap();
try {
// create ServerSocket using specified port
serverSocket = new ServerSocket(socketServerPORT);
}catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SocketConnectAsyncTask atSockConn = new SocketConnectAsyncTask();
atSockConn.execute();
}
public int getPort() {
return serverSocket.getLocalPort();
}
public void closeSocket() {
if (serverSocket != null) {
try {
serverSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
private class SocketConnectAsyncTask extends AsyncTask<Void, Void, Void>
{
int count = 0;
Handler mHandler;
Socket socket;
@Override
//public void run() {
protected Void doInBackground(Void... params) {
try {
/*// create ServerSocket using specified port
serverSocket = new ServerSocket(socketServerPORT);
*/
while (true) {
// block the call until connection is created and return
// Socket object
socket = serverSocket.accept();
count++;
message += "#" + count + " from "
+ socket.getInetAddress() + ":"
+ socket.getPort() + "\n";
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
ReceiveMessage atRecMsg = new ReceiveMessage(socket, this.mHandler);
atRecMsg.execute();
}
}
class ReceiveMessage extends AsyncTask<Void, Void, Void> {
private Socket clientSocket;
private Handler mHandler;
private BufferedReader input;
public ReceiveMessage(Socket clientSocket, Handler mHandler)
{
this.clientSocket = clientSocket;
this.mHandler = mHandler;
try {
this.input = new BufferedReader(new InputStreamReader(this.clientSocket.getInputStream()));
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
protected Void doInBackground(Void... params) {
while(true) {
try {
String read = input.readLine();// blocking
Message msg = Message.obtain();
msg.obj = read; // Put the string into Message, into "obj" field.
msg.setTarget(mHandler); // Set the Handle
System.out.println("Here is what I read: " + read);
//updateConversationHandler.post(new updateUIThread(read));
//mHandler.sendMessage();
msg.sendToTarget(); //Send the message
try {
OutputStream outputStream = clientSocket.getOutputStream();
PrintStream printStream = new PrintStream(outputStream);
printStream.print("OK");
printStream.close();
}
catch (IOException e) {
e.printStackTrace();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
Thread.sleep(500);
} catch (InterruptedException ie) {
}
}
//return null;
}
}
public String getIpAddress() {
String ip = "";
try {
Enumeration<NetworkInterface> enumNetworkInterfaces = NetworkInterface
.getNetworkInterfaces();
while (enumNetworkInterfaces.hasMoreElements()) {
NetworkInterface networkInterface = enumNetworkInterfaces
.nextElement();
Enumeration<InetAddress> enumInetAddress = networkInterface
.getInetAddresses();
while (enumInetAddress.hasMoreElements()) {
InetAddress inetAddress = enumInetAddress
.nextElement();
if (inetAddress.isSiteLocalAddress()) {
ip = inetAddress.getHostAddress();
}
}
}
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
ip += "Something Wrong! " + e.toString() + "\n";
}
return ip;
}
}
服务器类的调用如下：
myServer = new Server (this); // this = activity
所以我认为服务器正在运行。尝试通过以下呼叫从客户端连接...
Client myClient = new Client(sServerIpAddress, sServerPort, Commands.this);
...我收到以下异常：
W/System.err: java.net.ConnectException: failed to connect to /192.168.200.2 (port 47803) from /:: (port 48982): connect failed: ECONNREFUSED (Connection refused)
W/System.err: at libcore.io.IoBridge.connect(IoBridge.java:138)
W/System.err: at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:129)
W/System.err: at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:356)
W/System.err: at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
W/System.err: at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
W/System.err: at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:356)
W/System.err: at java.net.Socket.connect(Socket.java:616)
W/System.err: at java.net.Socket.connect(Socket.java:565)
W/System.err: at java.net.Socket.<init>(Socket.java:445)
W/System.err: at java.net.Socket.<init>(Socket.java:248)
W/System.err: at emu.apps.com.jollybell.Client.doInBackground(Client.java:45)
W/System.err: at emu.apps.com.jollybell.Client.doInBackground(Client.java:20)
W/System.err: at android.os.AsyncTask$2.call(AsyncTask.java:333)
W/System.err: at java.util.concurrent.FutureTask.run(FutureTask.java:266)
W/System.err: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
W/System.err: at java.lang.Thread.run(Thread.java:764)
W/System.err: Caused by: android.system.ErrnoException: connect failed: ECONNREFUSED (Connection refused)
W/System.err: at libcore.io.Linux.connect(Native Method)
W/System.err: at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:126)
W/System.err: at libcore.io.IoBridge.connectErrno(IoBridge.java:152)
W/System.err: at libcore.io.IoBridge.connect(IoBridge.java:130)
W/System.err: ... 17 more
老实说，即使在所有可能的论坛中搜索了几个小时之后，我也不知道出了什么问题。
如果有帮助，这是客户端类：
class Client extends AsyncTask<String, Void, String> {
public interface ServerResponse {
void serverResultReceived(String output);
}
String sIpAddress, sPort, response;
private Socket socket;
private PrintWriter out;
public ServerResponse delegate = null;
public Client(String sIpAddress, String sPort, ServerResponse delegate)
{
this.sIpAddress = sIpAddress;
this.sPort = sPort;
this.delegate = delegate;
}
//@Override
//public void run() {
@Override
protected String doInBackground(String... params) {
try {
InetAddress serverAddr = InetAddress.getByName(this.sIpAddress);
socket = new Socket(serverAddr, Integer.parseInt(this.sPort));
// First send command
out = new PrintWriter(new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream())),
true);
out.print(params[0]);
// ... then wait for answer
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(
1024);
byte[] buffer = new byte[1024];
int bytesRead;
InputStream inputStream = socket.getInputStream();
/*
* notice: inputStream.read() will block if no data return
*/
while ((bytesRead = inputStream.read(buffer)) != -1) {
byteArrayOutputStream.write(buffer, 0, bytesRead);
response += byteArrayOutputStream.toString("UTF-8");
}
} catch (UnknownHostException e1) {
e1.printStackTrace();
} catch (IOException e1) {
e1.printStackTrace();
}
finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
return response;
}
@Override
protected void onPostExecute(String result) {
delegate.serverResultReceived(result);
}
}
答案 0 :(得分：0)
所以大家。前段时间，但我发现了如何解决我的问题。
首先，在客户端有一个小问题。我正在使用“out.print”函数编写，然后在服务器中使用“readLine（）”函数进行等待。
readLine期望一行的结束，因此字符串应该以最后的“/ n”发送，或者必须使用函数“println”而不是print。
其次，当我启动2个Android设备时，他们无法相互通信。我仍然没有找到原因，但使用相同的设备来运行服务器和客户端应用程序为我工作。