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POJava try-catch not working
 

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  1. POJava try-catch not working
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    <p>wondering if someone can tell me why my try-catch doesn't work. I enter a character when I should be entering an integer and the program just exits with the exception. It's identical to a try-catch I wrote in another program. Not sure why it doesn't work. :(</p> <pre><code>import java.io.*; import java.util.*; public class Lab8FileIO { public static void main(String[] args) throws IOException { int menuChoice = 0; String filename, userInput, choice; boolean playAgain = true; char response; Scanner keyboard = new Scanner(System.in); while (playAgain) { // Display menu and get user selection displayMenu(); do { try { menuChoice = keyboard.nextInt(); if ((menuChoice &lt; 1) || (menuChoice &gt; 4)) // Make sure user enters a number within the specified range System.out.print("You must enter a number from 1 to 4!"); } catch (InputMismatchException e) { System.out.print("You must enter a number from 1 to 4!"); keyboard.nextInt(); } } while (menuChoice &lt; 1 &amp;&amp; menuChoice &gt; 4); // Get input/output filename from user System.out.print("\nEnter filename in the format filename.txt: "); filename = keyboard.next(); switch (menuChoice) { // Write to file case 1: PrintWriter outputFile = new PrintWriter(filename); userInput = getUserInput(); System.out.println("I am writing your input to filename: " + filename + "\n"); outputFile.println(userInput); outputFile.close(); break; // Read from file case 2: File file = new File(filename); Scanner inputFile = new Scanner(file); System.out.println("I am reading from filename: " + filename + "\n"); while (inputFile.hasNextLine()) { String line = inputFile.nextLine(); System.out.println(line); } inputFile.close(); break; // Append to file case 3: FileWriter appendFile = new FileWriter(filename, true); userInput = getUserInput(); System.out.println("I am appending your input to filename: " + filename + "\n"); appendFile.write(userInput); appendFile.close(); break; // Exit case 4: System.out.println("Goodbye!"); System.exit(0); break; } // Ask user to play again do { System.out.print("\nWould you like to continue (Y/N)? "); choice = keyboard.next(); response = Character.toUpperCase(choice.charAt(0)); } while (response != 'Y' &amp;&amp; response != 'N'); // Keep asking until user enters correct response if (response == 'Y') // Play again { playAgain = true; System.out.println(); } else if (response == 'N') // Quit { playAgain = false; System.out.println("\nThanks for playing!"); } } </code></pre> <p>} </p> <pre><code>public static void displayMenu() { System.out.println("File IO Options:"); System.out.println("1) Write"); System.out.println("2) Read"); System.out.println("3) Append"); System.out.println("4) Quit"); System.out.print("What would you like to do: "); } public static String getUserInput() { String str; Scanner keyboard = new Scanner(System.in); System.out.println("Start typing. Hit enter when you're done:"); str = keyboard.nextLine(); return str; } } </code></pre> <p>This is the error I'm getting:</p> <p>File IO Options:<br> 1) Write<br> 2) Read<br> 3) Append<br> 4) Quit<br> What would you like to do: a<br> You must enter a number from 1 to 4!Exception in thread "main"<br> java.util.InputMismatchException<br> at java.util.Scanner.throwFor(Scanner.java:840)<br> at java.util.Scanner.next(Scanner.java:1461)<br> at java.util.Scanner.nextInt(Scanner.java:2091)<br> at java.util.Scanner.nextInt(Scanner.java:2050)<br> at Lab8FileIO.main(Lab8FileIO.java:41)</p>
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    1. PTQuestion
    1. USspeedracer
    1. USspeedracer
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      1. POJava try-catch not working
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      1. VTDownMod
    1. COPost the stack trace, maybe you're trying to catch the wrong Exception *or* you are misplacing the block. You are probably not catching everything, `keyboard.nextInt();` is also called *inside* the catch.
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      1. USA--C
    2. CONote that if the `keyboard.nextInt()` *inside* the `catch` block raises an exception, it won't be caught, because you're already outside the `try` block.
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      1. POJava try-catch not working
      1. USruakh
    3. COThe other program in which I have a similar try-catch has `keyboard.nextInt();` in it. I don't understand why that one worked and this one doesn't.
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      1. USspeedracer
 

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