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Java.lang.classcastexception Cannot Be Cast To Java.lang.comparable

Ubuntu 16.04 installer cant see SSD drive Someone peeled an American flag sticker off of my truck. SCJP 1.4 - SCJP 6 - SCWCD 5 - OCEEJBD 6 - OCEJPAD 6 How To Ask Questions How To Answer Questions Istvan Kovacs Ranch Hand Posts: 100 posted 6 Then it means that when you want to use a TreeSet for your Set implementation, then either you need to make all your code aware that it's a TreeSet so you Of course not. weblink

Update 2: It would be sufficient if the comparator returns an int ∈ {-1, 0, 1}. I don't see it in your code sample. Lab colleague uses cracked software. Still, we need some surrounding code. –Rohit Jain Aug 17 '13 at 18:59 I am trying to create an array of Element.

How to comment uncomment single line and block of ... I cannot reproduce the problem with Java collections because there is no default collector that creates a SortedSet: java.util.SortedSet sortedSet = new TreeSet<>(); sortedSet.add("a"); sortedSet.add("b"); sortedSet .stream() .flatMap(s -> Arrays.asList(s.hashCode()).stream()) .collect(Collectors.toSet()); I also know sth like the following is allowed: heap = (K[]) new Comparable[capacity]; –user2692465 Aug 17 '13 at 19:31 1 Have you tried Element[] heap = (Element[])

Powered by Blogger. super T" is to ensure that T can also be java.sql.Timestamp which is a Comparable. Build me a brick wall! Somehow we have to give Arrays.sort a mechanism on how to compare my objects.

Why is (a % 256) different than (a & 0xFF)? XPath Tutorial - How to select elements in XPATH b... That is how we expect a SortedSet to work by default. http://stackoverflow.com/questions/14133600/java-cannot-cast-to-comparable-when-using-treemap there might be something that will do this for you.

Java Annotations Tutorial5. I am using the Java JungI graph package and Netbeans 7. Even in the reflection-variant that detects hash-collisions, there might come a SecurityManager into the way (see code below). Now the tricky thing is that when you assign your TreeSet to a Set type, then the flatMap(comparator, function) method isn't available anymore.

posted 6 years ago Edit: reply to Ravi's question why it was only required for TreeSet It isn't. https://coderanch.com/t/511227/java/java-lang-ClassCastException-Employee-cast JΛVΛSLΛNG member danieldietrich commented Oct 4, 2016 • edited There is still a problem (I already mentioned above: "Checking for hashCode collisions would be problematic."): hash(o1, o2) can be 0 for Change the array creating into "new Comparable[maxSize]", possibly "new Comparable[maxSize]" if your IDE gives a raw-type warning, and your code will work. It is no viable solution to search (once) for the most common comparator of two objects o1, o2.

How to escape String literal in Java using Eclipse... http://pgexch.com/java-lang-classcastexception-cannot/java-lang-classcastexception-cannot-be-cast-to-javax-xml-rpc-stub.html Which means you can not store Integers on LinkedList of String, from Java 5 it will result in compile time error. Are “la malplej juna” and “la plej maljuna” entirely interchangeable? extends SortedSet, ?

Join them; it only takes a minute: Sign up Java “cannot cast to Comparable” when using TreeMap [duplicate] up vote 4 down vote favorite Possible Duplicate: Java: SortedMap, TreeMap, Comparable? The RedBlackTree will contain at maximum 1 element then because it represents a Set and all elements are equal o_O. To actually do your sorting, you might want to make your FoodItems implement Comparable aswell and copy paste your actual compareTo logic in it. check over here I think the the RedBlackTree should still work.

We will not break anything. JΛVΛSLΛNG member danieldietrich commented Mar 24, 2016 Yes, great idea, I think it should be possible. xparse processor with multiple arguments Why is looping over find's output bad practice?

Good programmers write code that humans can understand." --- Martin Fowler Please correct my English.

The contract of Set says if I have a Set and I flatMap it, I'll get back a Set, with no promises about order. Would we find alien music meaningful? Share to Twitter Share to Facebook Labels: core java , error and exception , programming Location: United States 5 comments : Anonymous said... super T, ?

The first non-null element of a set may be a Comparable, but a) that doesn't guarantee that the other non-null elements of the set are Comparable and b) doesn't guarantee that We will also see how to minimize or avoid ClassCastException in Java by using Generics, as prevention is always better than cure. Update: Of course this does not make any sense at all (using -1 instead of hash(o1, o2)) because binary search within the tree isn't possible any more. http://pgexch.com/java-lang-classcastexception-cannot/java-lang-classcastexception-cannot-be-cast-to-org-omg-corba-object.html Some structures or methods simply require Comparables.

extends U> that, T thisElem, U thatElem); @Override SortedSet> zipWithIndex(); @Override SortedSet zipWithIndex(BiFunction switches the comparator to the natural one of the value, if No => falls back to another (unordered?) comparator, e.g. NewsKnowledge BaseTutorialsResourcesCoursesWhitepapersDealsJob BoardAboutAbout JCGsAdvertisingTerms of UsePrivacy Policy Examples Java Code Geeks Java Examples and Code Snippets AndroidcoreactivityanimationappActionBarActivityFragmentListActivityBluetoothBluetoothAdaptercameracontentBroadcastReceiverContentProviderIntentSharedPreferencesdatabasesqliteSQLiteDatabaseEmailgoogle mapsgraphicsCanvashardwareCameraSensorlocationmediaAudioManagerMediaRecordernetworkosAsyncTaskHandlerSystemClockPackageManagerpreferenceproviderContactsContractpublishingServicesockettelephonyPhoneStateListenerSmsManagerTelephonyManagertext-to-speechThreaduiAlertDialogAnalogClockButtonCheckBoxcomponentDatePickerDialogDigitalClockDrag and 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When you do things right, people won't be sure you've done anything at all. How to use?0Cast TreeMap.Submap return: SortedMap, back to TreeMap13Find element position in a Java TreeMap14Java TreeMap Comparator4Java. Either implement it: public class Stock implements Comparable { public int compareTo(Stock o) { // ... } } ... Student.java:package com.javacodegeeks.java.core; import java.util.Comparator; public class Student implements Comparable { private int id; private String name; private int currentYearOfStudy; public Student(int id, String name, int currYearOfStudy) { this.id = id; this.name

So If you have a blog with unique and interesting content then you should check out our JCG partners program. 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 139k16159236 add a comment| up I have looked and can not figure it out or find information on it that is helpful. Consider this code: Comparable[] foo = new Comparable[size]; foo[0] = Long.valueOf(123L); Element[] heap = (Element[]) foo; Element thisFails = heap[0]; // this isn't safe!

Ravi Kiran Va Ranch Hand Posts: 2234 I like... checks if the value is instanceof Comparable 3. Because in the case of a collision the value is arbitrary, say -1, the whole order is provably arbitrary in the general case.

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