Java Android-如何在服务重新启动时保留套接字连接
我有一个服务，它创建一个套接字服务器，并有一个客户端连接到它。连接保持打开状态以传输数据。服务是Java Android-如何在服务重新启动时保留套接字连接,java,android,sockets,tcp,connection,Java,Android,Sockets,Tcp,Connection,我有一个服务，它创建一个套接字服务器，并有一个客户端连接到它。连接保持打开状态以传输数据。服务是START\u STICKY。因此，当用户通过从最近的任务中滑动应用程序来终止应用程序时，将再次调用onCreate和onStartCommand函数。我不想重新初始化套接字，而是保持它的状态，就像用户刷任务杀死它之前一样，并保持不间断地传输数据 public class SendTasksService extends Service { static Socket socket=null;
START\u STICKYonCreateonStartCommandpublic class SendTasksService extends Service {
static Socket socket=null;
static boolean shouldRun=true;
static final int port = PORT_NO;
static ServerSocket listener = null;
@Override
public IBinder onBind(Intent intent) {
System.out.println("Service onBind.");
return null;
}
@Override
public void onCreate() {
System.out.println("Service onCreate.");
shouldRun=true;
try {
if(socket==null){
System.out.println("Starting Listening..");
listener = new ServerSocket(port);
System.out.println("Notification Started.");
}else{
System.out.println("Continuing With Old Socket..");
/*
How to get the socket if the connection
was made before swipe killing the app from recent
*/
}
}catch(Exception ioe){
System.out.println("Exception in listening.");
ioe.printStackTrace();
}
}
public void onDestroy() {
System.out.println("Service onDestroy.");
closeConnection();
}
public void closeConnection(){
//Wind up work and close connection
/*
This should also remove any socket information saved anywhere
*/
}
public int onStartCommand(Intent intent, int flags, int startid) {
System.out.println("Service onStartCommand.");
try{
new AsyncAction().execute();
}catch (Exception e) {
e.printStackTrace();
}
return START_STICKY;
}
private class AsyncAction extends AsyncTask<String, Void, String> {
protected String doInBackground(String... args) {
while(shouldRun) {
try {
if(socket==null) {
socket = listener.accept();
/*
Socket connection established here.
Save this socket state or preserve it somehow
So that connection does not break on killing the app
*/
}else{
/*
Continue with the old socket data, and resume connection
*/
}
if(socket==null)
continue;
}catch(Exception e){
System.out.println("Exception after Break");
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(String result) {
}
}
}
静态public class SendTasksService extends Service {
static Socket socket=null;
static boolean shouldRun=true;
static final int port = PORT_NO;
static ServerSocket listener = null;
@Override
public IBinder onBind(Intent intent) {
System.out.println("Service onBind.");
return null;
}
@Override
public void onCreate() {
System.out.println("Service onCreate.");
shouldRun=true;
try {
if(socket==null){
System.out.println("Starting Listening..");
listener = new ServerSocket(port);
System.out.println("Notification Started.");
}else{
System.out.println("Continuing With Old Socket..");
/*
How to get the socket if the connection
was made before swipe killing the app from recent
*/
}
}catch(Exception ioe){
System.out.println("Exception in listening.");
ioe.printStackTrace();
}
}
public void onDestroy() {
System.out.println("Service onDestroy.");
closeConnection();
}
public void closeConnection(){
//Wind up work and close connection
/*
This should also remove any socket information saved anywhere
*/
}
public int onStartCommand(Intent intent, int flags, int startid) {
System.out.println("Service onStartCommand.");
try{
new AsyncAction().execute();
}catch (Exception e) {
e.printStackTrace();
}
return START_STICKY;
}
private class AsyncAction extends AsyncTask<String, Void, String> {
protected String doInBackground(String... args) {
while(shouldRun) {
try {
if(socket==null) {
socket = listener.accept();
/*
Socket connection established here.
Save this socket state or preserve it somehow
So that connection does not break on killing the app
*/
}else{
/*
Continue with the old socket data, and resume connection
*/
}
if(socket==null)
continue;
}catch(Exception e){
System.out.println("Exception after Break");
e.printStackTrace();
}
}
return null;
}
protected void onPostExecute(String result) {
}
}
}
套接字无法持久化。您保存了
套接字的toString（）
，仅此而已。您可以通过创建一个扩展应用程序的类来修复它
public class Engine extends Application {
@Override
public void onCreate() {
super.onCreate();
/* do something here */
}
}
然后在清单中做一些类似的事情
<manifest...>
<application
android:name=".[yourclassname]" //
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
我又做了一些修补，但无法四处保存连接。所以我想如果我能在连接断开之前通知我的客户端我的服务器希望它重新连接，我就能自动重新连接。如果有人觉得这有用的话。
刚刚在manifest的服务标签中添加了android:stopWithTask=“false”
，并在服务中添加了ridonTaskRemoved
。在onTaskRemoved
中，我向客户端发送了重新连接到服务器的信号
public void onTaskRemoved(Intent rootIntent) {
System.out.println("Service onTaskRemoved.");
try {
PrintWriter out = new PrintWriter(socket.getOutputStream());
out.print("RECONNECT\0");
out.flush();
out = null;
}catch(Exception e) {
System.out.println("Exception in closing connection.");
e.printStackTrace();
}
}
所以我不能保存我的连接不被破坏？另一个解决方案可能是使用数据报，但这也会涉及到更改我的客户机。@dumplingParadox：“所以我不能保存我的连接而不被破坏？”——正确。您不能假设您的流程将永远存在，即使有服务。一旦进程终止，系统可能需要一段时间才能重新启动它，即使是START\u STICKY
。你需要将你的应用程序设计为支持任意时间段，在这些时间段内，你没有进程，也没有连接到服务器。我找到了一种解决方法，你没有保存状态是对的。标记为正确答案。：）自定义应用程序
类不会阻止进程终止。但问题是保留套接字的状态？