Java

Synchronized method is not working in java because the lock on the synchronised method is not attached to a single object. When the Java method is synchronised with the synchronised…

Synchronized block is not working in java because the lock on the synchronised block is not attached to a single object. When the Java code block is synchronised with the…

The java No enclosing instance of type is accessible. Must qualify the allocation with an enclosing instance of type (e.g. x.new A() where x is an instance of ). exception…

The Local variable name defined in an enclosing scope must be final or effectively final exception occurs where the local variable used in the lamda expression is not a final…

Synchronized keyword is not working in java because the thread lock object is not correctly attached to the thread. Because of this, the Java thread synchronisation doesn’t work as expected.…

The Java exception Loading class com.mysql.jdbc.Driver'. This is deprecated. The new driver class iscom.mysql.cj.jdbc.Driver’. occurs because the deprecated mysql driver class is configured or used in the mysql database connection.…

The java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/testdb exception occurs if the suitable driver is not found to connect mysql database from java application. The MySQL JDBC driver is not…

The java.lang.ClassNotFoundException: com.mysql.jdbc.Driver exception occurs if the MySQL JDBC driver class can not found in the java class path. The Class.forName() fails to loads the mysql driver class that is…

The java.lang.NullPointerException occurs when a java variable does not point to any object and is accessed for any operation. The java.lang.NullPointerException is a runtime exception. The java.lang.NullPointerException is an exception…

The java exception java.util.regex.PatternSyntaxException: Illegal character range near index occurs when an Illegal or inappropriate character range is used to match the regular expression. The range is defined by a…

The java.util.regex.PatternSyntaxException: Illegal repetition near index 0 exception occurs when the regular expression special characters such as $ { } are used inside the java search string. When processing in…

The java exception java.util.regex.PatternSyntaxException: Unclosed counted closure near index occurs when a string matches by the regular expression special character ‘{’ open curly bracket without close curly bracket. In a…

The java.util.regex.PatternSyntaxException: Illegal repetition exception occurs when the regex dialects ‘{’ and ‘}’ are not used for repetition qualifier. In java, the regular expression dialects ‘{‘ and ‘}’ have special…

The backward slash “\” is used to escape characters in the java string. If a string contains a backward slash “\”, a escape character is added along with backward slash…

Removing an element from the java array is done by locating the item index and shifting the rest of the items to the index position. The Java array can’t be…

The Integer.parseInt() method in java converts an int string to an int value. We can also convert String to Integer object using Integer.valueOf() method. You can use the Integer.parseInt() function to…

Java generate random number in range – Java Random int value generation classes such as ThreadLocalRandom, Random, and SplittableRandom are used to generate random integers within a specific range in…

You can use the HashMap keys, HashMap values, and HashMap Entry Object to iterate over the HashMap in Java. The iterator will run through each element in the HashMap one…

To convert a String to an int in Java, you can use the Integer.parseInt() method. In Java, we can use the Integer.valueOf() method to convert a String to an Integer.…

The java exception java.util.regex.PatternSyntaxException: Unmatched closing ‘)’ happens when the string is matched by the regular expression special character ‘)’ closing parentheses. In a search string, the character “(” and…