get all elements in JTree

I have a problem on my app <JTree>, i have a JTree like this

root
x1
x1,1
x1,2
x2
x2,1
x2,2


now i want to iterate through all element x1,x2 and their childs and get it's value

output like: parent:x1,childs:x1,1|x1,2 parent:x2,childs:x2,1|x2,2

i need help please ?

What have you tried and what specifically are you having trouble with?

Code:

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public void useRecursion() {
    if (notDone) {
      useRecursion();
  }
}

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