get text from dynamically added jPanel

Question

I am adding dynamically subPanel to jPanel1 (with jTextField and jButton). Some of part code was borrowed from there.

Answer 1

Problem is: You are iterating over the children of jPanel1:

jPanel1.getComponents();

And expect there to be a JTextField:

if (children[i] instanceof JTextField){
     String text = ((JTextField)children[i]).getText();
     System.out.println(text);
}

But since you have added subPanels to jPanel1, the children of jPanel1 are subPanels, not JTextFields!

So, in order to access the JTextFields, you'll have to iterate over the children of the subPanels in a second for-loop!

Example:

Component[] children = jPanel1.getComponents();
// iterate over all subPanels...
for (Component sp : children) {
    if (sp instanceof subPanel) {
        Component[] spChildren = ((subPanel)sp).getComponents();
        // now iterate over all JTextFields...
        for (Component spChild : spChildren) {
            if (spChild instanceof JTextField) {
                String text = ((JTextField)spChild).getText();
                System.out.println(text);
            }
        }
    }
}

Answer 2

I know this a bit old question to answer, but still it can potentially help more future viewers. My initial response was to write this as a comment in @Oliver Schmidt , but as I don't have 50 Reputation yet, so decided to write this in a separate answer.

To get access to the components contained in the dynamically added jPanel "subPanel", you don't necessarily need to use second for loop, you can access subPanel's components directly by using the following line of code, for example,

String s1 = ((subPanel) sp).jcb1.getSelectedItem().toString().substring(1, 2); ...

So the overall code looks like,

String s1;
String s2;
String s3;
String text;
Component[] c = jPanel1.getComponents();

for (Component sp : c) {
    if (sp instanceof subPanel) {

        //access the component from properly type converted subPanel
        s1 = ((subPanel) sp).jcb1.getSelectedItem().toString().substring(1, 2);
        s2 = ((subPanel) sp).jcb2.getSelectedItem().toString().substring(1, 2);
        s3 = ((subPanel) sp).jcb3.getSelectedItem().toString().substring(1, 2);
        text = ((subPanel) sp).myLabel.getText();
    }
}

System.out.println(s1);
System.out.println(s2);
System.out.println(s3);
System.out.println(text);