No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:compile (default-compile) on project <project-name>: Compilation failure No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? Solution Go to Windows –> Preferences –> Java […]
Oracle query to find alphanumeric data in column
Sample Data SELECT ‘3874’ col FROM DUAL UNION ALL SELECT ’74’ col FROM DUAL UNION ALL SELECT ‘123’ col FROM DUAL UNION ALL SELECT ’22FRE’ col FROM DUAL UNION ALL SELECT ‘ABCD’ col FROM DUAL UNION ALL SELECT ‘AB33FRE’ col…
How to delete folder in GitHub repository and local git repository
Sometimes we want to delete folders from GitHub but there is no option in GitHub to delete folder directly. If you want to delete folder from GitHub then we need to open the folder and delete all files one by…
Evaluation Order of Java Operand
Evaluation Order of Java Operand Before applying any operator, all the Operands should be evaluated from left to right.
Precedence Of Java Operator
Precedence Of Java Operators Uniary Operators :- [ 1st level [ ], x++, x– ], [ 2nd level ++x, –x, ~, ! ], [ 3rd level new, <type> ]. Arithmetic Operators:- *, /, %, +, – . Shift Operators:- >>,…
New Operator New operator can be used for the creation of Object. Note:- There is no delete operator in java, Destruction of useless Objects will take care by Garbage Collector.
The only ternary operator available in java is conditional operator. int a = ( 10<20 ) ? 30 : 40 ; System.out.println( a) ; // 30 Nesting of conditional operator is also allowed in java. int x = ( 100>200…
Java compiler version and project facet selected java version not matching. So we need to change java project facets version according java compiler. Solution Change java project facets java version according java compiler. Select Project –> Right Click –> Project Facets –> Select version in version drop down.
Probably you are using java 8 and the other computer is using java 7. Java requires references to variables from inner classes to be final variables. Java 8 will make them effectively final if you don’t reassign. Probably you are using java 8 and the other computer is using java 7. Java requires references to […]
Garbage Collection In C++, programmer is responsible for the creative of new objects& for destruction of useless objects Usually the programmer is taking very much car while creating object& he is ignoring that destruction of useless objects. Due to this negligence at cretin point of time, memory may not be available for the creation of […]
Arrays Class This Class Present in java.util package. It defines several utility methods applicable for arrays. Sorting the elements of Arrays:-Arrays class defines the following three methods to perform sorting. Public static void sort(Primitive p) to sort the elements of primitive array, according to natural sorting order. Public static void sort(Object o) to sort the […]
Collections It is an utility class present in java.util package. It defines several utility methods for collection implemented class object. Sorting a list public static void sort(List l), to sort the elements of List, according to natural sorting order. In this case compulsory Objects should be Homogeneous & comparable otherwise we will get ClassCastException. The […]
Enhancement Sun people introduces, the following 2 interface in 1.6 version as the part of collection Framework. 1) NavigableSet 2) NavigableMap. NavigableSet It is the child interface of SortedSet, which defines several methods to support navigation. Ceiling(e): It returns the lowest element, which is greater than equal to e. Higher(e): Returns the lowest element which […]
Queue This interface has introduced in 1.5 version. If we want to represent, group of Objects Prior to processing, then we should go for Queue. In general Queue follow FIFO, but we can customize based on our requirement. *image* From 1.5 version on wards linkedList also implement Queue interface. LinkedList implementation of Queue always follows […]
Properties It is the child class of Hashtable. In this case both key and value should be String Object only. Constructor Properties p = new Properties () Important methods of Properties String getProperty (String name). Return the value associated with the specified Property. If the specified property is not available then we will get null. […]
WeakHashMap It is exactly same as HashMap, except the following difference. In the case of HashMap, an object is not eligible for garbage, if it is associated with HashMap, even though it doesn’t contain any external reference. i.e HashMap dominates garbage collector. But in the case of WeakHashMap, if an object is not having any […]