Чашечка Java

[Solved] java.lang.unsupportedclassversionerror Unsupported major.minor version 55.0, 57.0, 60.0, 61.0 Error in Java? Examples The java.lang.unsupportedclassversionerror unsupported major.minor version 60.0 error comes in Java environment when you compile your Java file in a higher Java version like Java 16 and then trying to run the same Java program in lower Java version like Java 11. Java is backward compatible, I mean you can run your Java 15 binary or JAR into Java or JRE 16 but vice-versa is not true. You can not run a Java program that is compiled in a higher Java version into lower JRE. class file version changes between every Java version and class file generated by the javac command of Java 16 installation is not appropriate for JRE of Java 15 Installation. Java Interview questions and tutorials Read: http://www.java67.com/2012/10/how-to-fix-javalangunsupportedclassversionerror-major-minor-version-49-50-51.html

How to deal with java.net.SocketException: Broken pipe, Connection reset, and Too many open files in Java? [Solution] In this blog, I plan to talk about some common exceptions and errors that arise while using sockets. Quite often, these socket issues arise out of application bugs, system settings, or system load. It might be an unnecessary delay to go to product teams, only to discover that the issue can be resolved by tuning/configuring your local settings. Understanding these messages will not only help resolve the issues but also make a conscious effort in avoiding these scenarios while developing applications. Java Interview questions and tutorials Read: http://www.java67.com/2019/02/7-common-socket-errors-and-exception-in-java.html

How to solve java.sql.BatchUpdateException: String or binary data would be truncated in Java JDBC? [Solution] Recently I was working in a Java application that uses Microsoft SQL Server at its backend. The architecture of the Java application was old i.e. even though there was heavy database communication back and forth there was no ORM used like no Hibernate, JPA, or Apache iBatis. The Java application was using an old DAO design pattern, where the DB related classes which are responsible for loading and storing data from the database was calling the stored procedure to do their job. These stored procedures take data from Java applications and insert it into SQL Server tables. Java Interview questions and tutorials Read: http://www.java67.com/2016/10/how-to-solve-javasqlbatchupdateexception-string-or-binary-data-would-be-truncated.html

How to Fix Reference Error: $ is not defined in jQuery and JavaScript [Solved] Hello JavaScript developer, if you are wondering how to fix the Reference Error $ is not defined while using jQuery then you have come to the right place. "Reference Error: $ is not defined" is one of the common JavaScript errors which come when you try to use $, which is a shortcut of jQuery() function before you load the jQuery library like calling $(document).ready() function. "ReferenceError: XXX is not defined"is a standard JavaScript error, which comes when you try to access a variable or function before declaring it. Since jQuery is also a JavaScript library, you must first include the declaration of the jQuery function or $() before you use it. Java Interview questions and tutorials Read: http://www.java67.com/2020/07/fixing-referenceerror-is-not-defined-in.html

How to Fix SQLServerException: The index is out of range? JDBC Example I was executing a stored procedure against SQL SERVER 2008 database from Java program using CallableStatement, but unfortunately, I was getting the following error "SQLServerException: The index 58 is out of range". Since I am passing a lot of parameters I thought that something is wrong with a number of parameters I was passing to the stored proc. My stored procedure had 58 INPUT parameters, as soon as I removed the 58th INPUT parameter the error goes away, which confirmed my belief that SQL Server supports a maximum of 57 INPUT parameters in stored procedure via JDBC. Java Interview questions and tutorials Read: http://www.java67.com/2015/12/sqlserverexception-index-58-is-out-of-range-SQL-SERVER-stored-proc.html

How to deal with java.lang.NullPointerExceptionin Java? Cause, Solution, and Tips to avoid NPE Hello Java programmers, if you want to learn what is NullPointerExcpeiton in Java and how to deal with NullPointerException or NPE then you have come to the right place. NullPointerException in Java is an unchecked Exception defined in java.lang package and comes when a member of an object either field or method is called on an object which is null. null is a keyword in Java that means nothing and the calling method on an object whose value is null will result in NullPointerException. Since the default value of Objectis null, if you call any method or access any field on an Object which is not initialized will throw NullPointerException. Java Interview questions and tutorials Read: http://www.java67.com/2021/05/how-to-solve-nullpointerexception-in-java.html

How to fix org.springframework.beans.factory.BeanCreationException: Error creating bean with name X [Java Spring] If you are using the Spring framework in your Java application and getting this error during startup it means Spring is not able to initialize the bean X and add it into its application context, Why? There could be multiple reasons like a typo on the spring bean name. Let's take a closer look at the stack trace to find out the real reason: BeanInstantiationException: Could not instantiate bean class [X]: No default constructor found; nested exception is java.lang.NoSuchMethodException: X.() Here X is the class, which is declared as Spring bean. The error clearly says that the default constructor is not present in class X. Java Interview questions and tutorials Read: http://www.java67.com/2017/07/solving-orgspringframeworkbeansfactoryb-beancreation-exception-java-spring.html

When to throw and catch Exception in Java? [Best Practice] Exceptions are one of the confusing and misunderstood topics in Java, but at the same time, too big to ignore. In fact, good knowledge of Errors and Exception handling practices is one criterion, which differentiates a good Java developer from an average one. So what is confusing about Exception in Java? Well, many things like When to throw Exception or When to catch Exception, When to use checked exception or unchecked exception, should we catch errors like java.lang.OutOfMemoryError? Shall I use an error code instead of an Exception and a lot more? Well, I cannot answer all these questions in one post, so I will pick the first one when to catch or throw any Exception in Java. Java Interview questions and tutorials Read: http://www.java67.com/2021/06/when-to-throw-and-catch-exception-in.html

[Solved] Caused by: java.sql.SQLSyntaxErrorException: ORA-01722: invalid number in Java and Oracle Hello guys, if you are getting below error in your Java program and wondering how to solve this or just stuck then you have come to the right place. In this article, I will explain to you what causes the " java.sql.SQLSyntaxErrorException: ORA-01722: invalid number" error when you connect to an Oracle database from a Java program and how you can solve it. But, first of all, let's take a look at the stack trace of this error which looks like below: Java Interview questions and tutorials Read: http://www.java67.com/2021/06/caused-by-java-01722-invalisqlsqlsyntaxerrorexception-ORA-01722-invalid-number.html

Осенние конференции JUG Ru Group: онлайн и офлайн, Москва и Питер Как проводить IT-конференции в 2022-м: в офлайне или онлайне? Одни люди ратуют за живое общение, а другие уже полюбили возможность подключиться из любой точки планеты. Мы решили пойти навстречу всем, и получился нестандартный конференционный формат: — Первая пара дней проходит в онлайне, спикеры выступают удалённо. А позже ещё один день происходит старый добрый офлайн на конференционной площадке. — У тех, кто не готов добраться до этой площадки, есть возможность и ко второй части подключиться по интернету. Пожалуй, так упустишь часть атмосферы, но доклады увидишь. Впервые опробовали это весной, а теперь по такому принципу пройдут все конференции нашего осеннего сезона. У первой половины из них офлайн-часть пройдёт в Петербурге, у второй — в Москве. Представляем Хабру даты и подробности. Читать: https://habr.com/ru/post/680164/?utm_campaign=680164

How to call REST API by sending HTTP Request using cURL command in Linux? Example Tutorial The curl or cURL command of Linux is a compelling and versatile command which allows you to send sophisticated HTTP requests right from your Linux command line window. You can use the cURL command to test your RESTful Web Services by sending GET and POST requests, doing authentication, saving a cookie in the file, etc. The curl command is, in fact, the go-to tool for many Java and Spring developers working in web applications and consuming data from the secured RESTful Web Services. Still, you can also use it to test your simple REST Web APIs without security. I have used it many times to check if our Web service is up or not, or is there any error while accessing those services. Java Interview questions and tutorials Read: http://www.java67.com/2017/10/how-to-test-restful-web-services-using.html

Top 50 Microsoft SQL Server Interview Questions with Answers for 1 to 3 Years Experienced Hello guys, if you are preparing for an SQL Server Interview or a Java developer position where SQL Server skills are required and looking for SQL server interview questions then you have come to the right place. In the past, I have shared 10 SQL query Interview questionsand 50 database and SQL questions, and today, I am going to share some SQL Server conceptual and theory questions which are very popular in interviews. The list not only includes Microsoft SQL server related questions, like isnull vs coalesce but also many general SQL and database design concepts like referential integrity, joins, normalization, window functions, etc. Java Interview questions and tutorials Read: http://www.java67.com/2019/08/microsoft-sql-server-phone-interview-questions-answers.html

How to use DROP command to remove tables in Oracle, MySQL and SQL Server Hello guys, if you want to learn about DROP command in SQL then you have come to the right place. Earlier, I have shared the best free SQL and Database coursesand several tutorials to learn SELECT, GROUP BY, and other important commands, and in this article, I will show you to use the DROP command in SQL. DROP is one of the basic SQL commands, which is used to DROP database objects. Since it's part of ANSI SQL, the DROP command is supported by all major database vendors, including Oracle, MySQL, and Microsoft SQL Server. A SQL DROP TABLE statement is used to delete a table definition and all data from a table, but DROP can also be used to drop index, view, trigger, or any other database object. Java Interview questions and tutorials Read: http://www.java67.com/2021/04/sql-drop-command-example-mysql-.html

Difference between Correlated Subquery vs Non-Correlated (Self Contained) subquery in SQL - Example If you are wondering what is correlated and non-correlated subqueries in SQL and looking to understand the difference between them then you have come to the right place. Earlier, I have shared free SQL and Database courses and today, I am going to talk about one of the common SQL concepts of subqueries, a query inside another query. There are two types of subqueries in SQL, correlated subquery and self-contained subquery, also known as nested, non-correlated, uncorrelated, or simply a subquery. The main difference between them is, self-contained (non-correlated) subqueries are independent of the outer query, whereas correlated subquery has a reference to an element from the table in the outer query. Java Interview questions and tutorials Read: http://www.java67.com/2019/09/difference-between-correlated-subquery.html

Difference between ISNULL() and COALESCE() function in SQL? Example Even though both ISNULL() and COALESCE() function provides alternate values to NULL in T-SQL and Microsoft SQL Server e.g. replacing NULL values with empty String, there are some key differences between them, which is often the topic of SQL Server interview. In this article, you will not only learn the answer to this question but also learn how to use COALESCE and ISNULL function properly. One of the main differences between them is that  COALESCE() is a standard SQL function but ISNULL() is Microsoft SQL Server-specific, which means it's not guaranteed to be supported by other database vendors like Oracle, MySQL, or PostgreSQL. Java Interview questions and tutorials Read: http://www.java67.com/2017/04/4-differences-between-isnull-and-coalesce-in-sql-server.html

How to Fix java.sql.BatchUpdateException: Error converting data type float to numeric - Java + SQL Server This error can come if you are inserting or updating a NUMERIC column in the Microsoft SQL Server database from a Java Program using the executeUpdate()method, I mean executing a batch update query. It could also happen if you are calling a stored procedure and passing a float value corresponding to a NUMERIC column, and the value happened to be out-of-range like generating "Arithmetic overflow error converting numeric to data type numeric"on the SQL Server end. For example, if your column is defined as NUMERIC (6,2) the maximum value it can represent is 9999.99, not 999999.99. Java Interview questions and tutorials Read: http://www.java67.com/2019/04/javasqlbatchupdateexception-error-converting-data-type-float-to-numeric.html

Top 20 Docker Interview Questions with Answers for Beginners and Experienced Developers Hello guys, if you are preparing for a Java developer interview, a DevOps engineer interview or any software developer interview, one tool which should pay most attention is Docker. It's a container tool which allows you to package and deploy your application in cloud. Docker has many benefits as it not only standardized packaging and deployment but works nicely with Kubernetes which takes the scalability and automatic restart of your application. These are just a couple of benefits but because of all these, Docker has become an essential tool for every programmer and developer and that's why they are also quite important for interviews. Java Interview questions and tutorials Read: http://www.java67.com/2022/08/docker-interview-questions-with-answers.html

Как получать сущности со связями в Spring Rest контроллере Туториал для начинающих разработчиков Spring, в котором рассказывается, почему в REST сервисе может не заработать самый обычный метод findById() и как это можно исправить. Читать: https://habr.com/ru/post/679722/?utm_campaign=679722

Java News Roundup: Helidon 3.0, GraalVM 22.2, IntelliJ IDEA 2022.2, Vert.x Virtual Threads This week's Java roundup for July 25th, 2022, features news from OpenJDK, JDK 19, JDK 20, Spring project updates, Helidon 3.0, GraalVM 22.2, Quarkus 2.11.1 and 2.10.4, Micronaut 3.5.4, Eclipse Vert.x virtual threads incubator, Jakarta EE 10 updates, IntelliJ IDEA 2022.2, JUnit 5.9.0, Apache Software Foundation project updates and Multik 0.2.0. By Michael Redlich Read: https://www.infoq.com/news/2022/08/java-news-roundup-jul25-2022/

Jetpack Compose 1.2 Includes Lazy Grids, Support for Google Fonts, and More Jetpack Compose 1.2 stabilizes a number of features, including lazy grids, nested scroll, easing curve for animations, and more. In addition, it brings several new experimental features, like custom layouts and downloadable fonts, and fixes many issues. By Sergio De Simone Read: https://www.infoq.com/news/2022/07/jetpack-compose-1-2/