Techie Shah

JDK 21 is scheduled to be released in September 2023 as specified in    JSR 395 . The main 3 features included in JDK 21  are  a) Sequenced Collections According to  OpenJDK , a sequenced collection has first and last elements, and the elements between them have successors and predecessors. A sequenced collection supports common operations at either end, and it supports processing the elements from first to last and from last to first (i.e., forward and reverse). b)  Virtual Threads According to OpenJDK ,  Virtual threads are lightweight threads that dramatically reduce the effort of writing, maintaining, and observing high-throughput concurrent applications. c)  String Templates (Preview)  According to OpenJDK ,  Enhance the Java programming language with  string templates . String templates complement Java's existing string literals and text blocks by coupling literal text with embedded expressions and  template processors  to produce specialized results

In Java language, DOT is a special character in the regular expression. If you have the following string String str = "He is a boy. He is my friend"; The following statement will return an empty string array String tokens[] = s.split("."); Solution: You can split a string based on DOT in the following two ways a) String tokens[] = str.split("[.]"); b) String tokens[] = str.split("\\."); The same solution also applies to the following characters a) WHITE SPACE  b) COMMA c) COLON Complete Example: public class StringSplit {      public static void main(String[] args ) {           String str = "He is a boy.He is my friend" ;           String tokens [] = str .split( "[.]" );           System. out .println( tokens [0]);           System. out .println( tokens [1]);          //or using escape character           tokens = str .split( "\\." );           System. out .println( tokens [0])

  Problem : If you get the following error while git checkout or git pull  git unable to unlink old [file name] invalid argument Solution Most probably the file is opened and locked in another application. Close that application and then try again, you will successfully continue with the respective git command.

 Problem: If you have defined the data type of your database column as the following character strings then you will not be able to save the Unicode characters. a) char b) varchar c) text Solution: Change the data type of your database column to the following Unicode character strings a) nchar b) nvarchar c) ntext

  Problem org.springframework.beans.factory.UnsatisfiedDependencyException : Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration': Unsatisfied dependency expressed through method 'setFilterChains' parameter 0: Error creating bean with name 'filterChain' defined in class path resource [com/.class]: Failed to instantiate [org.springframework.security.web.SecurityFilterChain]: Factory method 'filterChain' threw exception with message: This object has already been built at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.resolveMethodArguments( AutowiredAnnotationBeanPostProcessor.java:817 ) ~[spring-beans-6.0.4.jar:6.0.4] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject( AutowiredAnnotationBeanPostProcessor.java:769 ) ~[spring-beans-6.0.4.jar:6.0.4] at org.spri

  Exception NoSuchMethodError: javax.xml.ws.WebFault.messageName()Ljava/lang/String Solution You are most probably using jdk6 or earlier versions of Java if you encounter this exception. You can fix this exception using the following steps a) Download the latest jax-ws b) Place the downloaded jar inside jre/lib/ endorsed folder OR c) Please the download jar file inside the web server lib endorsed folder like if using JBoss then place it inside jboss\lib\ endorsed if using Tomcat then place it inside tomcat\lib\ endorsed

 Problem  Closing a connection for you.  Please close them yourself: org.jboss.resource.adapter.jdbc.jdk5.WrappedConnectionJDK5@6e3a0a96 2021-11-16 12:23:43,715 WARN  [com.arjuna.ats.arjuna.logging.arjLoggerI18N] (Thread-1371) [com.arjuna.ats.arjuna.coordinator.TransactionReaper_7] - TransactionReaper::doCancellations worker Thread[Thread-1371,5,jboss] successfully canceled TX a11267b:ff8e:61915e7e:1413e57 2021-11-16 12:23:43,715 WARN  [com.arjuna.ats.arjuna.logging.arjLoggerI18N] (Thread-1371) [com.arjuna.ats.arjuna.coordinator.BasicAction_58] - Abort of action id a11267b:ff8e:61915e7e:1413e5d invoked while multiple threads active within it. 2021-11-16 12:23:43,715 WARN  [com.arjuna.ats.arjuna.logging.arjLoggerI18N] (Thread-1371) [com.arjuna.ats.arjuna.coordinator.CheckedAction_2] - CheckedAction::check - atomic action a11267b:ff8e:61915e7e:1413e5d aborting with 1 threads active! 2021-11-16 12:23:43,731 WARN  [com.arjuna.ats.arjuna.logging.arjLoggerI18N] (WorkerThread#73[10.72.65.85:5

 Introduction In this tutorial, we will learn how to add @author comments to every new class that we create. We can achieve it using either of the following two solutions Solution 1:  Automatically add @author comments to every new class using Files and Code Templates Open File -> Settings -> Editor -> File and Code Templates -> Includes Click on Includes . Under File Header , enter the following comments text /**  * @author ${USER}  * @Date ${DATE}   */ Intellij - add @author comments Solution 2: Autocompletion of @author Open File  ->  Settings  ->  Editor  -> Live Templates Select Java and then click on + button In Abbreviation, enter @a In template text , enter the following comments           /**             * @author ${USER}             * @Date ${DATE}            */ In option , Expands with select SPACE Intellij - Autocompletion @author You can simply add the @author comments by typing @a and then click SPACE

 Introduction In this post, we will learn how to convert Java String to Date  Example: import java.util.Date; public class DateConversion { public static void main(String[] args) {      SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");      try { Date date = sdf.parse("19-09-2020"); System.out.println(date);      } catch (Exception ex) { ex.printStackTrace();      } } } In Java 8 and onward versions, we can use the LocalDate and DateTimeFormatter class to convert a String to a LocalDate object. We will use the parse method of the LocalDate class to perform this conversion Example (using Java 8+ versions) import java.time.LocalDate; import java.time.format.DateTimeFormatter; public class DateConversion { public static void main(String[] args) { DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy"); try { LocalDate date = LocalDate.parse("19-09-2020",formatter); System.out.println(da