CODEWITHSUNDEEP
javaswinglotus-noteslotusagent
xog
xog

Reputation: 11

Sharing JFrame between Lotus Notes Agent, allowing data to be passed

I'm trying to share a JFrame between instances of a Lotus Notes Java agent. I would like to re-use my window instead of recreating it each time my agent executes.

My class, RaiseJira, extends JFrame, which extends Frame. When I run the following code, I get a ClassCastException.

Frame[] fs = Frame.getFrames();
for (int i = 0; i < fs.length; i++) {
    if (fs[i].getName().equals("RaiseJira")) {
        RaiseJira f = (RaiseJira) fs[i];
    }
}

If I cast it to a JFrame, it works fine and I have access to the JFrame methods. I'm trying to pass data to it using RaiseJira methods, so it needs to be of the correct type.

Am I missing something with downcasting? Also, am I missing an easier way of passing data to a common JFrame from separate agents?

Upvotes: 0

Views: 173

Answers (1)

dic19
dic19

Reputation: 17971

When I run the following code, I get a ClassCastException.

In your if condition:

if (fs[i].getName().equals("RaiseJira"))

Checking the frame's name doesn't make sense in this context because you can have a JFrame which is not instance of RaiseJira class but its name is set to "RaiseJira". For instance:

JFrame trollFrame = new JFrame("He he");
trollFrame.setName("RaiseJira");

Then you'll have a ClassCastException here:

if (fs[i].getName().equals("RaiseJira")) { // This is true
    RaiseJira f = (RaiseJira) fs[i]; // ClassCastException because is a JFrame not RaiseJira instance
}

If you want to be sure if a given frame is actually an instance of RaiseJira class you should use instanceof operator (I'd also use enhanced for loop but it's me):

for (Frame frame : Frame.getFrames()) {
    if (frame instanceof RaiseJira) {
        RaiseJira raiseJira = (RaiseJira) frame;
    }
}

Off-topic

I strongly suggest you read this topic: The Use of Multiple JFrames, Good/Bad Practice?

Upvotes: 1

Related Questions