Programming

URL: https://www.progressiverobot.com/java-convert-string-to-double/ Java String to double conversion can be done by many ways. Today we will look into some common ways to convert java string to double primitive data type or Double object. Note that since java supports autoboxing, double primitive type and Double object can be used interchangeably without any issues. Double d1 = […]

URL: https://www.progressiverobot.com/java-futuretask-example-program/ Sometime back I wrote a post about [Java Callable Future](/community/tutorials/java-callable-future-example) interfaces that we can use to get the concurrent processing benefits of threads as well as they are capable of returning value to the calling program. FutureTask is base concrete implementation of Future interface and provides asynchronous processing. It contains the methods to […]

URL: https://www.progressiverobot.com/java-lang-nullpointerexception/ java.lang.NullPointerException is one of the most popular [exceptions in java](/community/tutorials/exception-handling-in-java) programming. Anybody working in java must have seen this popping out of nowhere in the java standalone program as well as the [java web application](/community/tutorials/java-web-application-tutorial-for-beginners). java.lang.NullPointerException NullPointerException is a runtime exception, so we don’t need to catch it in the program. NullPointerException is raised in an […]

URL: https://www.progressiverobot.com/java-randomaccessfile-example/ Java RandomAccessFile provides the facility to read and write data to a file. RandomAccessFile works with file as large [array of bytes](/community/tutorials/string-byte-array-java) stored in the file system and a cursor using which we can move the file pointer position. Java RandomAccessFile !Java RandomAccessFile, RandomAccessFile in java, Java RandomAccessFile read write append example RandomAccessFile […]

URL: https://www.progressiverobot.com/java-socket-programming-server-client/ Welcome to Java Socket programming example. Every server is a program that runs on a specific system and listens on a specific port. Sockets are bound to the port numbers and when we run any server it just listens on the socket and waits for client requests. For example, tomcat server running on […]

URL: https://www.progressiverobot.com/java-thread-example/ Welcome to the Java Thread Example. Process and Thread are two basic units of execution. Concurrency programming is more concerned with java threads. Process A process is a self contained execution environment and it can be seen as a program or application. However a program itself contains multiple processes inside it. Java runtime […]

URL: https://www.progressiverobot.com/permutation-of-string-in-java/ In this tutorial, we will learn how to find the permutation of a String in a Java Program. It's a tricky question and asked mostly in Java interviews. Algorithm for Permutation of a String in Java We will first take the first character from the String and permute with the remaining chars. If […]