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Java.lang.integer Cannot Be Cast To Comparable


Possible repercussions from assault between coworkers outside the office How to delete the lines from a file that do not contain dot? posted 6 years ago Edit: reply to Ravi's question why it was only required for TreeSet It isn't. Post Reply Bookmark Topic Watch Topic New Topic programming forums Java Java JSRs Mobile Certification Databases Caching Books Engineering Languages Frameworks Products This Site Careers Other all forums Forum: Beginning Java more hot questions lang-java about us tour help blog chat data legal privacy policy work here advertising info mobile contact us feedback Technology Life / Arts Culture / Recreation Science Other More about the author

Unlike C-style languages, arrays are objects in Java. How to decline a postdoc interview if there is some possible future collaboration? Should you change a thermostat when changing your water pump How can an advanced (circa 7000 AD) spacefaring human civilization be prevented from entering its own solar system? What is the point of update independent rendering in a game loop? check here

Ljava Lang Object Cannot Be Cast To Ljava Lang Comparable

Examples Java Code Geeks is not connected to Oracle Corporation and is not sponsored by Oracle Corporation. Actually you can (it's a warning after all, not an error), but only if the rest of the code ensures that every interaction with the array respects the T type. java.lang.classcastexception java.util.arraylist cannot be cast to java.lang.string I have seen this happening a lot in beginners code based on Java Collection framework, Since ArrayList and String are not related to each Of course not.

That is how I did it now. –Avneesh Dec 21 '14 at 21:03 He doesn't need to declare it as Object[] -- his code as is (with elements declared Can a text in Latin be understood by an educated Italian who never had any formal teaching of that language? Many of advanced Java IDE like Eclipse and Netbeans will give you hyperlink to navigate till culprit line number in Java file. Treeset Comparator Why are wavelengths shorter than visible light neglected by new telescopes?

This was frequent problem with Java Collection classes like LinkedList and HashSet in Java which holds Object type but with introduction of Generics in Java 5 solved this problem by checking Here are couple of more examples, which is self explanatory. Hence my Rob Prime wrote:It's essential to hide the array from any outside code because otherwise you can cast the T[] to Object[] and then add anything. http://stackoverflow.com/questions/2112343/java-integer-obj-cant-cast-to-comparable Powered by Blogger.

Still, we need some surrounding code. –Rohit Jain Aug 17 '13 at 18:59 I am trying to create an array of Element. Java Comparable How to use?0Cast TreeMap.Submap return: SortedMap, back to TreeMap13Find element position in a Java TreeMap14Java TreeMap Comparator4Java. I don't see it in your code sample. It can be best explained with an example.

Cannot Be Cast To Java.lang.comparable Treeset

Here is the relevent portion of MyListADT: public abstract class MyListADT implements Cloneable { protected int length; protected int maxSize; protected T[] list; public MyListADT(int size) { maxSize = https://coderanch.com/t/496341/java/Generics-Comparable You cannot refer to a superclass (or interface) "object" through a subclass reference. Ljava Lang Object Cannot Be Cast To Ljava Lang Comparable That said, the safest choice for the created array type is what T extends. Object Cannot Be Cast To Comparable Boss sends a birthday message.

You didn't provide a Comparator so the TreeSet casted the element to a comparable and that caused the Exception because your class didn't implement it. my review here JPA Mini Book2. TreeSet and TreeMap use sorting for their internal storage. Java is a trademark or registered trademark of Oracle Corporation in the United States and other countries. Create Generic Array Java

Object[] objects = new Integer[10]; Number[] numbers = (Number[]) objects; numbers[0] = Integer.valueOf(0); // OK numbers[1] = 1; // OK numbers[2] = Double.valueOf(2.2d); // fails Rob Spoor Sheriff Posts: 20720 extends E> c) { return new TreeSet(c); } public static create(SortedSet s) { return new TreeSet(s); } // not too sure if this is guaranteed to be safe...public static http://bestimageweb.com/cannot-be/integer-cannot-be-cast-to-comparable.php You can also be a guest writer for Java Code Geeks and hone your writing skills!

Where to take phone interview while at work Why is (a % 256) different than (a & 0xFF)? Compareto Java You can even expose the Object[], but you have to claim its true type - Object[]. share|improve this answer answered Dec 23 '14 at 2:16 newacct 73.2k16107157 add a comment| up vote 1 down vote It's clear now.

super T>> extends MyListADTThat "?

As such, that code doesn't make sense. 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 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. Java Queue If those answers do not fully address your question, please ask a new question.

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 Sorted map by value0Comparable not working for treemap0How to sort a treemap and display its values and indices of the values and also skip to the next index if the previous Java Interview Questions6. navigate to this website Look at the error message, your Comparable comes from the default package rather than java.lang: Exception in thread "main" java.lang.ClassCastException: java.lang.Integer cannot be cast to Comparable That is, you can't cast

How to reply? How to check if a number is a palindrome or not in... xparse processor with multiple arguments How to delete the lines from a file that do not contain dot? SortedSet / SortedMap are interfaces.

This leads to ClassCastException if object is not of type on which you are casting it. You can, however, refer to any subclass object through the name of its implementing interface or any superclass. C++ calculator using classes Build me a brick wall! share|improve this answer answered Jan 3 '13 at 5:38 assylias 178k26340491 last note is interesting –Subin Jan 3 '13 at 5:46 add a comment| up vote 5 down vote

Java Collection classes like HashMap, ArrayList, Vector or Hashtable which is not using Generics. 2. Oracle 10g Pagination Query - SQL Example for Java... The declaration should be public class MyArrayList,V> create() { return new TreeMap(); } public static create(Comparator