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Fix possible NPE from WebSocketAdapter #7294

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Dec 16, 2021
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Fix possible NPE from WebSocketAdapter #7294

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7 changes: 5 additions & 2 deletions ...t/websocket-jetty-api/src/main/java/org/eclipse/jetty/websocket/api/WebSocketAdapter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -21,10 +21,11 @@
public class WebSocketAdapter implements WebSocketListener
{
private volatile Session session;
private RemoteEndpoint remote;

public RemoteEndpoint getRemote()
{
return session.getRemote();
return remote;
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IMO return session == null ? null : session.getRemote(); might be better. This is minor, but could save the remote field. And I think the readability is not affected too much either way.

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It would be more surprising for getRemote() to suddenly start returning null after it was non-null.

Let the usage of Remote trigger the exceptions indicating that you no longer have a valid connection/session/whatnot.

}

public Session getSession()
Expand All @@ -34,7 +35,8 @@ public Session getSession()

public boolean isConnected()
{
return session.isOpen();
Session sess = this.session;
return (sess != null) && (sess.isOpen());
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I think just return session != null && session.isOpen(); should be more readable. Creating sess here seems redundant.

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This is standard multi threading coding practice.
The value of this.session can actually change between the 2 evaluations (non-null check and isopen).
It could go from non-null to null between the two checks.

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Ah, I see. Thanks.

}

public boolean isNotConnected()
Expand All @@ -58,6 +60,7 @@ public void onWebSocketClose(int statusCode, String reason)
public void onWebSocketConnect(Session sess)
{
this.session = sess;
this.remote = sess.getRemote();
}

@Override
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