Home > Cannot Be > Java.lang.integer Cannot Be Cast To Comparable

Java.lang.integer Cannot Be Cast To Comparable

Contents

Join them now to gain exclusive access to the latest news in the Java world, as well as insights about Android, Scala, Groovy and other related technologies. Browse other questions tagged java generics or ask your own question. I thought this is a typical trick people use to create an object/comparable array using generics E[] arr = E[] new Object[size]; E[] carr = E[] new Comparable[size]; –user2692465 Aug 17 posted 6 years ago And if you want to get the smallest item in the list you might find an easier way to sort the List then return the item in click site

How to Create and Evaluate XPath Expression in Jav... public T[] toArray(T[] a) { // Estimate size of array; be prepared to see more or fewer elements int size = size(); T[] r = a.length >= size ? Hmmm. Email address: Newsletter168,095 insiders are already enjoying weekly updates and complimentary whitepapers! http://stackoverflow.com/questions/18292282/java-lang-classcastexception-ljava-lang-comparable-cannot-be-cast-to

Ljava Lang Object Cannot Be Cast To Ljava Lang Comparable

Smallest\n5. With my stack that is Object, but in Krep's case using "new Comparable[...]" is probably better. posted 6 years ago Till today i was adding Strings so didn't realized that , but when i added Custom Object the concept was clear .

How EXACTLY can +=/-= operators be interpreted? Also write your own classes and method to take advantage of Generics to provide type-safety as shown in this example of How to write parameterized class. That's why the toArray method in Collection requires you to pass an array - it reads the actual type of the array using reflection, and if needed, creates another array to Treeset Comparator Rob Spoor Sheriff Posts: 20720 68 I like...

Safety - Improve braking power in wet conditions Alternating Fibonacci Build me a brick wall! Cannot Be Cast To Java.lang.comparable Treeset That should solve the warning, but the ClassCastException will still exist. Invalid initial and maximum heap size in JVM - How... http://stackoverflow.com/questions/2112343/java-integer-obj-cant-cast-to-comparable The class declaration reads: public class MyArrayList extends MyListADT So I am not extending (or implementing) Comparable with my collection class, I am just telling it to accept any

Drawing a torso with a head (using \draw) Wrong way on a bike lane? Java Comparable Does Intel sell CPUs in ribbons? public class MyVertex implements Comparable { @Override public int compareTo(Object o) { // comparison logic goes here } } or alternately, you can pass a comparator to the constructor of TreeMap. Your code works; inserting the following main method into your code prints the expected result: public static void main(String[] args) { Stack stack = new Stack(10); stack.push("text"); String popped = stack.pop();

Cannot Be Cast To Java.lang.comparable Treeset

Spring Interview Questions7. https://coderanch.com/t/496341/java/Generics-Comparable In this case, the subclass, MinMaxStack, extends Stack with a specific type for E, therefore, it "sees" elements as a specific type of array, which it is not. Ljava Lang Object Cannot Be Cast To Ljava Lang Comparable Which means you can not store Integers on LinkedList of String, from Java 5 it will result in compile time error. Object Cannot Be Cast To Comparable share|improve this answer edited Jan 3 '13 at 5:43 answered Jan 3 '13 at 5:38 rai.skumar 4,76231839 add a comment| up vote 0 down vote - First you should make class

C++ calculator using classes Build me a brick wall! http://tcsmacs.net/cannot-be/java-lang-integer-cannot-be-cast-to-java-lang-string-solution.php So how are you "exposing" elements? How to escape String literal in Java using Eclipse... ClassCastException are simple like NullPointerException just look the stack-trace and go to the line number. Create Generic Array Java

However, the conversion is valid only in cases where a class extends a parent class and the child class is casted to its parent class.For example, the following snippet throws a Istvan Kovacs Ranch Hand Posts: 100 posted 6 years ago Krep Lock wrote: public class MyArrayList extends MyListADT { T[] list = (T[]) new Object[maxSize]; } Exception in thread For instance, a very simple stack implementation (no bounds checking): public class Stack { T[] array; int index; public Stack(int size) { array = (T[])new Object[size]; index = 0; } public navigate to this website class Stack { protected E[] elements = (E[])new Object[1]; } class IntStack extends Stack { void push(Integer i) { // subtly accessing elements as Integer[] which it's not elements[0] = i;

Other Java debugging and troubleshooting tutorials How to solve java.util.NoSuchElementException in Java JDBC - java.lang.ClassNotFoundException: com.mysql.jdbc.Driver Solution How to fix java.io.NotSerializableException: org.apache.log4j.Logger Error in Java How to fix java.sql.SQLException: Invalid column Compareto Java Still, we need some surrounding code. –Rohit Jain Aug 17 '13 at 18:59 I am trying to create an array of Element. It's also a good idea to refresh your knowledge on type-casting in Java.

Common source of java.lang.ClassCastException Following are some of the most common source of ClassCastExcepiton in Java: 1.

My AccountSearchMapsYouTubePlayNewsGmailDriveCalendarGoogle+TranslatePhotosMoreShoppingWalletFinanceDocsBooksBloggerContactsHangoutsEven more from GoogleSign inHidden fieldsSearch for groups or messages NewsKnowledge BaseTutorialsResourcesCoursesWhitepapersDealsJob BoardAboutAbout JCGsAdvertisingTerms of UsePrivacy Policy Examples Java Code Geeks Java Examples and Code Snippets AndroidcoreactivityanimationappActionBarActivityFragmentListActivityBluetoothBluetoothAdaptercameracontentBroadcastReceiverContentProviderIntentSharedPreferencesdatabasesqliteSQLiteDatabaseEmailgoogle mapsgraphicsCanvashardwareCameraSensorlocationmediaAudioManagerMediaRecordernetworkosAsyncTaskHandlerSystemClockPackageManagerpreferenceproviderContactsContractpublishingServicesockettelephonyPhoneStateListenerSmsManagerTelephonyManagertext-to-speechThreaduiAlertDialogAnalogClockButtonCheckBoxcomponentDatePickerDialogDigitalClockDrag and DropEventsExpandableListViewGridViewHorizontalScrollViewImageButtonImageViewLinearLayoutListViewNotificationsPasswordProgressBarProgressDialogRadioButtonRadioGroupRatingBarRelativeLayoutScrollViewSelectorSettingsSpinnerSurfaceViewTextBoxTimePickerToastToggleButtonWebViewviewMenuOnClickListenerViewPagerwidgetAutoCompleteTextViewEditTextFrameLayoutSeekBarSlidingDrawerStackViewTextViewViewFlipperxmlgamescanvasmain Here is all the code which created the problem - public class StackMain { public static void main(String[] args) { MinMaxStack minMaxStack = new MinMaxStack(); Random ran = new Random(); for Making the generic element / key type bound on Comparable was also not an option because then it wouldn't be possible to create a TreeSet / TreeMap with non-Comparable objects using Java Queue Java Collection classes like HashMap, ArrayList, Vector or Hashtable which is not using Generics. 2.

Now add this method to your stack, and modify main: public T[] toArray() { T[] destination = (T[])new Object[array.length]; System.arraycopy(array, 0, destination, 0, array.length); return destination; } public static void main(String[] SCJP 1.4 - SCJP 6 - SCWCD 5 - OCEEJBD 6 - OCEJPAD 6 How To Ask Questions How To Answer Questions Krep Lock Ranch Hand Posts: 43 posted 6 posted 6 years ago Istvan Kovacs wrote:The problem is that you create an Object[], which cannot be cast to T[]. my review here The consequence of this is that arrays can't be cast in either direction. (Generics can, but with specific and arcane rules about extends and super; that's another matter.) share|improve this answer

Is Area of a circle always irrational Formula 1 rebus Do the Leaves of Lórien brooches have any special significance or attributes? posted 6 years ago Istvan Kovacs wrote:Even if you do that, it will fail if the array is passed to the outside world (you cannot cast Comparable[] into String[]). Java Annotations Tutorial5. Eg: public class MyVertex implements Comparable { @Override public int compareTo(MyVertex o) { } } - But if you want to compare on the basis of more than one attribute of

Career OpportunitiesKnowledge BaseCoursesNewsResourcesTutorialsWhitepapersThe Code Geeks Network.NET Code GeeksJava Code GeeksSystem Code GeeksWeb Code GeeksHall Of FameAndroid Alert Dialog ExampleAndroid OnClickListener ExampleHow to convert Character to String and a String to Character US Election results 2016: What went wrong with prediction models? However, I was trying to cast the reference to a comparable/object array to some a subclass.