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POCannot pop() more than once from the static stack
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  1. POCannot pop() more than once from the static stack
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    copied!<p>I need to use a static stack in one of my android application. Here's how i used it:</p> <p>In the Constants File: </p> <pre><code>public static Stack&lt;String&gt; st = new Stack&lt;String&gt;(); </code></pre> <p>And in the Activity File, inside the onBackPressed method following logic is used:</p> <pre><code>if (!Constants.st.isEmpty()) { Log.i("CHECK", "Stack is not empty."); Log.v("CHECK", "PEEK: " + Constants.st.peek()); Constants.st.pop(); if(Constants.st.isEmpty()){ Log.i("CHECK", "Stack is empty."); }else{ Log.v("CHECK", "PEEK after POP: " + Constants.st.peek()); } }else{ Log.i("CHECK", "Stack is empty."); } </code></pre> <p>Now when i press back button once it works (i mean pop() function works), then second time it( pop() function ) doesn't. Here is the Log of the above logic:</p> <pre><code>: Stack is not empty. : PEEK: UI_FirstActivity : Stack is empty. : Stack is not empty. : PEEK: UI_SecondActivity : PEEK after POP: UI_FirstActivity : Stack is not empty. : PEEK: UI_FirstActivity : PEEK after POP: UI_FirstActivity </code></pre> <p>PS: Another thing is that whenever all these UI.. functions contains different dynamically created forms shown on the same activity. Now when we enter/show any method/form its name i.e., UI.. is been pushed in the stack.</p> <p>PPS: I am fine with downvote, but a simple explanation will be very helpful. </p> <p>PPPS: It seems that <strong>EJB</strong> is assuming that i am assuming :-). I will again try to explain what exactly is happening: I have an <strong>activity</strong> in which i am choosing to show various forms but one at a time. each method UI_First... represents one form. now what happens is that sometimes one of the form is skipped from showing because it contains no views for example UI_Second... So after UI_First... UI_Third form is shown. Now when the user presses the back button ideal situation is that program will skip the UI_Second.. (because it contains no views) and open UI_First... To implement this functionality i used a stack where whenever a form is shown i.e., when UI_First... method is called its name is pushed in the stack. and when back button is pressed it is popped. I apologize if i was not clear enough. </p> <p>PPPPS: i got the problem 10 mins ago. it was exactly was <strong>pratik</strong> is saying in the answer so i am going to accept his answer.</p>
 

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