Category Archives: Java

Immutable objects

Posted on April 15, 2018 by

Most of the objects in Java are mutable. It means that their state/fields can be changed after the object was created. The examples of those are: ArrayList, Calendar, StringBuilder. Immutable objects An object is immutable if its state/fields cannot be … Continue reading →

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Delete directory with contents in Java

Posted on March 24, 2018 by

Removing empty directory in Java is as simple as calling File.delete() (standard IO) or Files.delete() (NIO) method. However, if the folder is not empty (for example contains one or more files or subdirectories), these methods will refuse to remove it. … Continue reading →

Posted in Java, Maven, Uncategorized | Tagged , , , | 3 Comments

How to delete file in Java

Posted on March 5, 2018 by

File management (good old CRUD: create, read, update, delete) is quite common operation in software development. In this short post I would like to present 2 ways of removing files in Java. Method available in every Java version Every Java … Continue reading →

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Importing WSDL with Java and Maven

Posted on February 18, 2017 by

SOAP web services are often used in commercial software. If we plan to use existing SOAP web service, we should receive a WSDL file which defines the contract between the web service and its clients. This contract defines at least: … Continue reading →

Posted in Java, Java EE, Maven, Web-Services, XML | Tagged , , , , | 1 Comment

Objects utility class in Java

Posted on February 15, 2017 by

Today I would like to quickly mention java.util.Objects class. The JavaDoc documentation for this class says: This class consists of static utility methods for operating on objects. These utilities include null-safe or null-tolerant methods for computing the hash code of … Continue reading →

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Default and static methods in interfaces in Java 8

Posted on February 13, 2017 by

Before Java 8 interfaces could only contain static fields (usually simple constants) and abstract methods. Java 8 provided the ability to define concrete (default and static) methods in interfaces. This new language feature is used extensively in Java core packages. … Continue reading →

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Database schema creation in JPA using SQL scripts

Posted on February 12, 2017 by

Recent versions of JPA provide a feature to automatically create the database objects (like tables, sequences or indexes), load initial data into database on application deployment; and also remove them after the application is undeployed. All that is needed is … Continue reading →

Posted in Hibernate, Java, Java EE, JPA | Tagged , , , | Leave a comment

Reading text file line by line in Java

Posted on December 18, 2014 by

Reading text files from hard disk is quite common task in software development practice. Usually we are interested in processing it line by line. In this article I would like to present few popular ways how to do it easily … Continue reading →

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Iterating through Java list backwards

Posted on December 13, 2014 by

The most natural method of iterating through a list in Java is to start from the first element of the list and then move forward until the last one is reached. While this is the most common, it is sometimes … Continue reading →

Posted in Guava, Java | Tagged , | 1 Comment

Usage of serialVersionUID in Java serialization

Posted on December 6, 2014 by

Java run-time associates with each serializable class a special version number known as serialVersionUID. This number is later used during deserialization process to verify if the application which performed the serialization and the application which is doing the deserialization have … Continue reading →

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