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Thread: Android Programming - Weird Problem

  1. #1
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    Exclamation Android Programming - Weird Problem

    I'm making an android program that will generate problems that u can solve. The issue is whenever I try to convert a CharSequence to an Integer, it throws an error. Heres my code:

    package com.android.jackson;
     
    import java.util.Random;
     
    import android.os.Bundle;
    import android.app.Activity;
    import android.text.Editable;
    import android.view.Menu;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.TextView;
     
    public class MainActivity extends Activity {
    	//Random
    	Random rand = new Random();
     
    	//Views
    	Button generate, btnAnswer;
    	TextView showingNOP, problem;
    	EditText nop, answer;
     
    	//Integers
    	int realAnswer,yourAnswer, one, two, right, wrong, aop;
     
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.activity_main);
     
    		//Initalizing IDS
    		generate = (Button) findViewById(R.id.generate);
    		btnAnswer = (Button) findViewById(R.id.bAnswer);
    		showingNOP = (TextView) findViewById(R.id.nop);
    		problem = (TextView) findViewById(R.id.problem);
    		nop = (EditText) findViewById(R.id.amount);
    		answer = (EditText) findViewById(R.id.answer);
     
    		generate.setOnClickListener(new View.OnClickListener() {
     
    			@Override
    			public void onClick(View v) {
     
    				aop = Integer.valueOf(nop.getText().toString());
    				generate.setEnabled(false);
    				nop.setEnabled(false);
    				generateProblem();
    			}
    		});
    	}
     
    	public void generateProblem(){
    		for(int i = 0; i < aop; i++){
     
    			btnAnswer.setOnClickListener(new View.OnClickListener() {
    				@Override
    				public void onClick(View v) {
    					//making random numbers
    					one = rand.nextInt((50 - 1) + 1) + 1;
    					two = rand.nextInt((50 - 1) + 1) + 1;
    					//getting answer
    					realAnswer = one + two;
    					yourAnswer = Integer.valueOf(answer.getText().toString());
    					//testing answer
    					if(realAnswer == yourAnswer){
    						right++;
    					}else{
    						wrong++;
    					}
    					//showing number of problems
    					showingNOP.setText("Number: " + aop);
     
    				}
    			});
    		}
    	}
    }

    Here's the error log by LogCat (I highlighted what I though were the main problems):


    02-08 15:31:16.278: D/dalvikvm(1706): Not late-enabling CheckJNI (already on)
    02-08 15:31:22.018: D/gralloc_goldfish(1706): Emulator without GPU emulation detected.
    02-08 15:31:22.198: W/IInputConnectionWrapper(1706): showStatusIcon on inactive InputConnection
    02-08 17:41:20.278: D/dalvikvm(1977): GC_FOR_ALLOC freed 87K, 5% free 3299K/3452K, paused 47ms, total 51ms
    02-08 17:41:20.348: D/gralloc_goldfish(1977): Emulator without GPU emulation detected.
    02-08 17:46:57.108: I/Choreographer(1977): Skipped 46 frames! The application may be doing too much work on its main thread.
    02-08 17:47:01.788: I/Choreographer(1977): Skipped 48 frames! The application may be doing too much work on its main thread.
    02-08 17:58:22.608: D/dalvikvm(2028): GC_FOR_ALLOC freed 90K, 5% free 3295K/3452K, paused 92ms, total 96ms
    02-08 17:58:22.678: D/gralloc_goldfish(2028): Emulator without GPU emulation detected.
    02-08 17:58:57.148: W/IInputConnectionWrapper(2028): showStatusIcon on inactive InputConnection
    02-08 18:04:15.648: D/dalvikvm(2083): GC_FOR_ALLOC freed 94K, 5% free 3291K/3452K, paused 75ms, total 75ms
    02-08 18:04:15.708: D/gralloc_goldfish(2083): Emulator without GPU emulation detected.
    02-08 18:04:25.448: D/AndroidRuntime(2083): Shutting down VM
    02-08 18:04:25.448: W/dalvikvm(2083): threadid=1: thread exiting with uncaught exception (group=0xb1a7bba8)
    02-08 18:04:25.488: E/AndroidRuntime(2083): FATAL EXCEPTION: main
    02-08 18:04:25.488: E/AndroidRuntime(2083): Process: com.android.jackson, PID: 2083
    02-08 18:04:25.488: E/AndroidRuntime(2083): java.lang.ClassCastException: android.text.SpannableStringBuilder cannot be cast to java.lang.String
    02-08 18:04:25.488: E/AndroidRuntime(2083): at com.android.jackson.MainActivity$1.onClick(MainAct ivity.java:41)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.view.View.performClick(View.java:4438)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.view.View$PerformClick.run(View.java:18422 )
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.os.Handler.handleCallback(Handler.java:733 )
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.os.Handler.dispatchMessage(Handler.java:95 )
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.os.Looper.loop(Looper.java:136)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at android.app.ActivityThread.main(ActivityThread.jav a:5017)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at java.lang.reflect.Method.invokeNative(Native Method)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at java.lang.reflect.Method.invoke(Method.java:515)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:779)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:595)
    02-08 18:04:25.488: E/AndroidRuntime(2083): at dalvik.system.NativeStart.main(Native Method)
    02-08 18:04:33.758: I/Process(2083): Sending signal. PID: 2083 SIG: 9
    02-08 18:09:02.868: D/dalvikvm(2138): GC_FOR_ALLOC freed 97K, 5% free 3288K/3452K, paused 139ms, total 145ms
    02-08 18:09:03.208: D/gralloc_goldfish(2138): Emulator without GPU emulation detected.
    02-08 18:09:14.108: D/AndroidRuntime(2138): Shutting down VM
    02-08 18:09:14.108: W/dalvikvm(2138): threadid=1: thread exiting with uncaught exception (group=0xb1a7bba8)
    02-08 18:09:14.138: E/AndroidRuntime(2138): FATAL EXCEPTION: main
    02-08 18:09:14.138: E/AndroidRuntime(2138): Process: com.android.jackson, PID: 2138
    02-08 18:09:14.138: E/AndroidRuntime(2138): java.lang.NumberFormatException: Invalid int: ""
    02-08 18:09:14.138: E/AndroidRuntime(2138): at java.lang.Integer.invalidInt(Integer.java:137)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at java.lang.Integer.parseInt(Integer.java:358)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at java.lang.Integer.parseInt(Integer.java:331)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at
    com.android.jackson.MainActivity$2.onClick(MainAct ivity.java:61)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.view.View.performClick(View.java:4438)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.view.View$PerformClick.run(View.java:18422 )
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.os.Handler.handleCallback(Handler.java:733 )
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.os.Handler.dispatchMessage(Handler.java:95 )
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.os.Looper.loop(Looper.java:136)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at android.app.ActivityThread.main(ActivityThread.jav a:5017)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at java.lang.reflect.Method.invokeNative(Native Method)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at java.lang.reflect.Method.invoke(Method.java:515)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:779)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:595)
    02-08 18:09:14.138: E/AndroidRuntime(2138): at dalvik.system.NativeStart.main(Native Method)
    02-08 18:12:54.268: D/dalvikvm(2200): GC_FOR_ALLOC freed 101K, 5% free 3285K/3452K, paused 163ms, total 167ms
    02-08 18:12:54.508: D/gralloc_goldfish(2200): Emulator without GPU emulation detected.
    02-08 18:16:12.188: D/dalvikvm(2259): GC_FOR_ALLOC freed 104K, 5% free 3282K/3452K, paused 50ms, total 54ms
    02-08 18:16:12.428: D/gralloc_goldfish(2259): Emulator without GPU emulation detected.
    02-08 18:16:21.368: D/AndroidRuntime(2259): Shutting down VM
    02-08 18:16:21.378: W/dalvikvm(2259): threadid=1: thread exiting with uncaught exception (group=0xb1a7bba8)
    02-08 18:16:21.378: E/AndroidRuntime(2259): FATAL EXCEPTION: main
    02-08 18:16:21.378: E/AndroidRuntime(2259): Process: com.android.jackson, PID: 2259
    02-08 18:16:21.378: E/AndroidRuntime(2259): java.lang.NumberFormatException: Invalid int: ""
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.Integer.invalidInt(Integer.java:137)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.Integer.parseInt(Integer.java:358)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.Integer.parseInt(Integer.java:331)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.Integer.valueOf(Integer.java:489)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at
    com.android.jackson.MainActivity$2.onClick(MainAct ivity.java:59)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.view.View.performClick(View.java:4438)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.view.View$PerformClick.run(View.java:18422 )
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.os.Handler.handleCallback(Handler.java:733 )
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.os.Handler.dispatchMessage(Handler.java:95 )
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.os.Looper.loop(Looper.java:136)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at android.app.ActivityThread.main(ActivityThread.jav a:5017)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.reflect.Method.invokeNative(Native Method)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at java.lang.reflect.Method.invoke(Method.java:515)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:779)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:595)
    02-08 18:16:21.378: E/AndroidRuntime(2259): at dalvik.system.NativeStart.main(Native Method)
    02-08 18:16:27.948: I/Process(2259): Sending signal. PID: 2259 SIG: 9
    02-08 18:18:39.978: D/dalvikvm(2317): GC_FOR_ALLOC freed 107K, 6% free 3278K/3452K, paused 48ms, total 55ms
    02-08 18:18:40.378: D/gralloc_goldfish(2317): Emulator without GPU emulation detected.
    02-08 18:18:48.708: D/AndroidRuntime(2317): Shutting down VM
    02-08 18:18:48.708: W/dalvikvm(2317): threadid=1: thread exiting with uncaught exception (group=0xb1a7bba8)
    02-08 18:18:48.798: E/AndroidRuntime(2317): FATAL EXCEPTION: main
    02-08 18:18:48.798: E/AndroidRuntime(2317): Process: com.android.jackson, PID: 2317
    02-08 18:18:48.798: E/AndroidRuntime(2317): java.lang.NumberFormatException: Invalid int: ""
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.Integer.invalidInt(Integer.java:137)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.Integer.parseInt(Integer.java:358)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.Integer.parseInt(Integer.java:331)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.Integer.valueOf(Integer.java:489)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at
    com.android.jackson.MainActivity$2.onClick(MainAct ivity.java:59)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.view.View.performClick(View.java:4438)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.view.View$PerformClick.run(View.java:18422 )
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.os.Handler.handleCallback(Handler.java:733 )
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.os.Handler.dispatchMessage(Handler.java:95 )
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.os.Looper.loop(Looper.java:136)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at android.app.ActivityThread.main(ActivityThread.jav a:5017)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.reflect.Method.invokeNative(Native Method)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at java.lang.reflect.Method.invoke(Method.java:515)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:779)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:595)
    02-08 18:18:48.798: E/AndroidRuntime(2317): at dalvik.system.NativeStart.main(Native Method)
    02-08 18:18:53.568: I/Process(2317): Sending signal. PID: 2317 SIG: 9
    02-08 18:22:19.858: D/dalvikvm(2379): GC_FOR_ALLOC freed 110K, 6% free 3275K/3452K, paused 47ms, total 50ms
    02-08 18:22:20.458: D/gralloc_goldfish(2379): Emulator without GPU emulation detected.
    02-08 18:22:27.288: D/AndroidRuntime(2379): Shutting down VM
    02-08 18:22:27.288: W/dalvikvm(2379): threadid=1: thread exiting with uncaught exception (group=0xb1a7bba8)
    02-08 18:22:27.298: E/AndroidRuntime(2379): FATAL EXCEPTION: main
    02-08 18:22:27.298: E/AndroidRuntime(2379): Process: com.android.jackson, PID: 2379
    02-08 18:22:27.298: E/AndroidRuntime(2379): java.lang.NumberFormatException: Invalid int: ""
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.Integer.invalidInt(Integer.java:137)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.Integer.parseInt(Integer.java:358)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.Integer.parseInt(Integer.java:331)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.Integer.valueOf(Integer.java:489)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at
    com.android.jackson.MainActivity$2.onClick(MainAct ivity.java:59)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.view.View.performClick(View.java:4438)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.view.View$PerformClick.run(View.java:18422 )
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.os.Handler.handleCallback(Handler.java:733 )
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.os.Handler.dispatchMessage(Handler.java:95 )
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.os.Looper.loop(Looper.java:136)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at android.app.ActivityThread.main(ActivityThread.jav a:5017)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.reflect.Method.invokeNative(Native Method)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at java.lang.reflect.Method.invoke(Method.java:515)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at com.android.internal.os.ZygoteInit$MethodAndArgsCa ller.run(ZygoteInit.java:779)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at com.android.internal.os.ZygoteInit.main(ZygoteInit .java:595)
    02-08 18:22:27.298: E/AndroidRuntime(2379): at dalvik.system.NativeStart.main(Native Method)
    02-08 18:22:29.968: I/Process(2379): Sending signal. PID: 2379 SIG: 9


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Android Programming - Weird Problem

    The errors seem to be self explanatory. Which one(s) don't you understand?
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Android Programming - Weird Problem

    All of them, I think im using the right methods, but its throwing an error. Can u give me the reasons why its catching an error?! Thanks!

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Android Programming - Weird Problem

    java.lang.NumberFormatException: Invalid int: ""
    An empty String is not a valid int value.

    android.text.SpannableStringBuilder cannot be cast to java.lang.String
    android.text.SpannableStringBuilder cannot be cast to java.lang.String
    I don't see any casting in the posted code. Where is line 59?
    If you don't understand my answer, don't ignore it, ask a question.

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