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Cannot Be Cast To Comparable


Collections.sort(List) has been able to prevent this using generics, but TreeSet / TreeMap couldn't. 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. 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 We have a great list of items on our menu.\n Would you like to see these items sorted by name or by price?\n 1 for name, 2 for price, 3 to have a peek here

JVM Troubleshooting Guide3. I highly recommend to use Generics while using any Collection classes or class which acts as container e.g. Comparable[]...) You should return a List instead of a T[]. Newton's second law for individual forces What do we call initial text of terminal Creating a table with FIXED length column widths Am I interrupting my husband's parenting? http://stackoverflow.com/questions/8699195/cannot-be-cast-to-java-lang-comparable

Cannot Be Cast To Java.lang.comparable Treeset

Spring Interview Questions7. The Java tutorials have a section giving more detail on all this at http://download.oracle.com/javase/tutorial/collections/interfaces/order.html. Difference between Primary key vs Foreign key in t... Or pass an instance of CompareByValue as parameter to the sort() method: Collections.sort(list, new CompareByValue()); share|improve this answer answered Oct 31 '13 at 21:20 Óscar López 139k16158236 add a comment| up

You may be able to use toArray(T[]) instead; however, due to type erasure you cannot do // cannot do // vvvvv return array.toArray( new T[ mySize ] ); So either Your How to deal with a coworker that writes software to give him job security instead of solving problems? How to remove duplicates elements from ArrayList i... Treeset Comparator Ravi Kiran Va Ranch Hand Posts: 2234 I like...

Browse other questions tagged java or ask your own question. what makes this problem worse is that it only comes during runtime, ClassCastException doesn't come at compile time which makes it hard to detect specially in large enterprise Java application or Why do I never get a mention at work? http://stackoverflow.com/questions/14133600/java-cannot-cast-to-comparable-when-using-treemap ClassCastException are simple like NullPointerException just look the stack-trace and go to the line number.

public class MyVertex implements Comparable { @Override public int compareTo(MyVertex o) { // do the comparison logic } } Other option is to pass a Comparator Object to TreeMap http://docs.oracle.com/javase/1.5.0/docs/api/java/util/TreeMap.html#TreeMap(java.util.Comparator) share|improve Java.lang.classcastexception Ljava.lang.object Cannot Be Cast To 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 super K>,V> create(Map

Cannot Be Cast To Java.lang.comparable Treemap

more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed https://coderanch.com/t/511227/java/java-lang-ClassCastException-Employee-cast The classes in my project (simplified): public class Item { private String itemID; private Integer price; public Integer getPrice() { return this.price; } } public class Store { private String storeID; Cannot Be Cast To Java.lang.comparable Treeset java.lang.Comparable Comparable is interface which contains one method compareTo where the sorting mechanism need to be placed.The return type of this method is int. Cannot Be Cast To Java.lang.comparable Priority Queue Reference Sheets Code Snippets C Snippets C++ Snippets Java Snippets Visual Basic Snippets C# Snippets VB.NET Snippets ASP.NET Snippets PHP Snippets Python Snippets Ruby Snippets ColdFusion Snippets SQL Snippets Assembly Snippets

Why put a warning sticker over the warning on this product? navigate here more hot questions question feed 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 For instance, don't use:Set set = new TreeSet()Use this instead:Set set = new TreeSet()This has nothing to do with your problem, but it's good practice to get used to. How to find middle element of LinkedList in Java i... Implement Comparable

Comperable Comperator 2013-01-25Byron Kiourtzoglou Tagged with: Comperable Comperator Do you want to know how to develop your skillset to become a Java Rockstar?Subscribe to our newsletter to start Rocking right now!To more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed Powered by Blogger. http://electrictricycle.net/cannot-be/cannot-be-cast-to-java-lang-comparable-set.html Java Comparable and Comparator Example to sort Objects Posted by: Byron Kiourtzoglou in Comparator, Comperable January 25th, 2013 In Java, it's very easy to sort an array or a list with primitive types.

So the output of the above program would be:[[id=1, name=Nikos, Current Year of Study=1], [id=4, name=Byron, Current Year of Study=5], [id=5, name=Ilias, Current Year of Study=4]]Now image that a client code Java Comparable In this case, presumably you want to sort alphabetically by title? super K>,V> create() { return new TreeMap(); } public static create(ComparatorThanks for the link Matthew Brown!

Android UI Designand many more .... Email address: Newsletter167,837 insiders are already enjoying weekly updates and complimentary whitepapers! Browse other questions tagged java arrays casting comparable or ask your own question. Java Comparable Example Is there a wage gap between smokers and non-smokers?

Byron is co-founder and Executive Editor at Java Code Geeks. Was This Post Helpful? 0 Back to top MultiQuote Quote + Reply ← Previous Topic Java Next Topic → Page 1 of 1 Related Java TopicsbetaUnsortedList$Link Cannot Be Cast To Hi genius , how to resolve this ,Causedby:java.lang.ClassCastException:java.lang.Integercannotbecasttojava.util.Collection April 15, 2015 at 10:58 PM Anonymous said... http://electrictricycle.net/cannot-be/cannot-be-cast-to-java-lang-comparable-hibernate.html Save India From Corruption - Anna Hazare.

Wouter Oet Saloon Keeper Posts: 2700 I like... He is currently acting as the team leader and technical architect for a proprietary service creation and integration platform for both the IT and Telecom industries in addition to a in-house add a comment| 5 Answers 5 active oldest votes up vote 11 down vote accepted How do I get MyVertex types to be casted to Comparables? Why are password boxes always blanked out when other sensitive data isn't?

Does a key signature go before or after a bar line? By using Generics in Collection classes and other places you can safely minimize java.lang.ClassCastException in Java. He is always fascinated by SOA, middleware services and mobile development. new TreeMap(new Comparator() { public int compare(MyVertex o1, MyVertex o2) { } }); share|improve this answer answered Jan 3 '13 at 6:33 Kumar Vivek Mitra 25.2k52554 add a comment| Not

Does Java pass by value or pass by reference - Int... Thanks in advnace .