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POIterating through hashmap - exception being thrown
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  1. POIterating through hashmap - exception being thrown
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    copied!<p>This is related to a question I asked earlier: <a href="https://stackoverflow.com/q/13896528/1005450">Iterating through hashmap and creating unique objects - trying to prevent duplicates</a></p> <p>And while I assumed I could apply a similar logic for my remove method that I had for my add method, the exception I have to check for a non existent record is getting thrown even though I know very well the record exists and should be removed. My delete method is as follows:</p> <pre><code> public boolean removePatron(int libraryCardNumber) throws PatronException { boolean patronRemoved = false; int keyToRemove = 0; for (Map.Entry&lt;Integer, Patron&gt; entry : patrons.entrySet()) { if (entry.getValue().getCardNumber() != libraryCardNumber) { throw new PatronException("This record does not exist"); } keyToRemove = entry.getKey(); } patrons.remove(keyToRemove); patronRemoved = true; return patronRemoved; } </code></pre> <p>For reference, the Patron objects look like this:</p> <pre><code>public class Patron { //attributes private String name = null; private int cardNumber = 0; //operations public Patron (String name, int cardNumber){ this.name = name; this.cardNumber = cardNumber; } public String getName(){ return name; } public int getCardNumber(){ return cardNumber; } } </code></pre> <p>My test simply adds three patrons first, and then tries to remove it by a card number that I know would exist. I added a println of the Patron's number in my add method so I could see them easily while messing with this in eclipse as they get added. </p> <pre><code> @Test public void testRemovePatron() { boolean exceptionThrown = false; try { testLibrary.addPatron("TestName"); testLibrary.addPatron("TestName2"); testLibrary.addPatron("TestName3"); testLibrary.removePatron(1); } catch (PatronException e) { System.out.println(e.getMessage()); exceptionThrown = true; fail("what the hell is going on"); } assertFalse(exceptionThrown); } </code></pre> <p>I get the exception from the remove method thrown every time. </p> <p>Edit: I made a small change to the provided answer, to account for needing to throw an exception if there was no match found:</p> <pre><code> public boolean removePatron(int libraryCardNumber) throws PatronException { boolean patronRemoved = false; int keyToRemove = 0; for (Map.Entry&lt;Integer, Patron&gt; entry : patrons.entrySet()) { if (entry.getValue().getCardNumber() == libraryCardNumber) { keyToRemove = entry.getKey(); patronRemoved = true; } } if (patronRemoved) { patrons.remove(keyToRemove); } else { throw new PatronException("This record did not exist"); } return patronRemoved; } </code></pre>
 

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