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1
7 package org.jboss.remoting;
8
9 import java.util.ArrayList  ;
10 import java.util.List ;
11 import java.util.ListIterator ;
12 import java.util.Timer ;
13 import java.util.TimerTask ;
14 import org.jboss.remoting.transport.ClientInvoker;
15
16
19 public class ConnectionValidator extends TimerTask
20 {
21 private List listeners = new ArrayList ();
22 private Client client = null;
23
24 private Timer validatorTimer = null;
25 private long pingPeriod = DEFAULT_PING_PERIOD;
26
27
30 public static final long DEFAULT_PING_PERIOD = 2000;
31
32 public ConnectionValidator(Client client)
33 {
34 this.client = client;
35 }
36
37 private void start()
38 {
39 validatorTimer = new Timer (false);
40 validatorTimer.schedule(this, pingPeriod, pingPeriod);
41 }
42
43 private void stop()
44 {
45 this.cancel();
46 validatorTimer.cancel();
47 validatorTimer = null;
48 }
49
50
51 public void addConnectionListener(ConnectionListener listener)
52 {
53 if(listener != null)
54 {
55 synchronized(listener)
56 {
57 if(listeners.size() == 0)
58 {
59 start();
60 }
61 listeners.add(listener);
62 }
63 }
64 }
65
66 public boolean removeConnectionListener(ConnectionListener listener)
67 {
68 boolean isRemoved = false;
69 if(listener != null)
70 {
71 synchronized(listeners)
72 {
73 isRemoved = listeners.remove(listener);
74 if(listeners.size() == 0)
75 {
76 stop();
77 }
78 }
79 }
80 return isRemoved;
81 }
82
83
86 public void run()
87 {
88 try
89 {
90 boolean isValid = checkConnection(client.getInvoker());
91 if(!isValid)
92 {
93 notifyListeners(new Exception ("Could not connect to server."));
94 }
95 }
96 catch(Throwable thr)
97 {
98 notifyListeners(thr);
99 }
100 }
101
102 private void notifyListeners(Throwable thr)
103 {
104 final Throwable t = thr;
105 synchronized(listeners)
106 {
107 ListIterator itr = listeners.listIterator();
108 while(itr.hasNext())
109 {
110 final ConnectionListener listener = (ConnectionListener) itr.next();
111 new Thread ()
112 {
113 public void run()
114 {
115 listener.handlerConnectionException(t, client);
116 }
117 }.start();
118 }
119 }
120 }
121
122 public static boolean checkConnection(ClientInvoker clientInvoker) throws Throwable
123 {
124 Object o = clientInvoker.invoke(new InvocationRequest(ConnectionValidator.class.getName(),
125 Subsystem.SELF, "$PING$", null, null, null));
126 InvocationResponse resp = (InvocationResponse) o;
127 Boolean b = (Boolean ) resp.getResult();
128 return b.booleanValue();
129 }
130
131
132 } |
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