In this article, we will discuss about how to read and write an excel file using Apache POI 1. Basic definitions for Apache POI library This section briefly describe about basic classes used during Excel Read and Write. HSSF is prefixed before the class name to indicate operations related to a Microsoft Excel 2003 file. […]
This article talks about reading and writing PDF using iText PDF library. pom.xml <dependency> <groupId>com.itextpdf</groupId> <artifactId>itextpdf</artifactId> <version>5.5.10</version> </dependency> P.S Tested with iTextPdf 5.5.10 1. iText – Write PDF iText PdfWriter example to write content to a PDF file. PdfWriteExample.java package com.mkyong; import com.itextpdf.text.*; import com.itextpdf.text.pdf.PdfWriter; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; public class […]
In this article, we will discuss about how to read and write an excel file using JExcel API, a simple library and widely used for simple operations which do not involve a high level of formatting and complex formulas based operations. P.S Tested with JExcel API – 2.6.12 1. Download JExcel Maven user. pom.xml <dependency> […]
Java multi threads example to show you how to use Semaphore and Mutex to limit the number of threads to access resources. Semaphores – Restrict the number of threads that can access a resource. Example, limit max 10 connections to access a file simultaneously. Mutex – Only one thread to access a resource at once. […]
The static keyword in Java is a modifier used to create memory efficient code. It helps in managing the memory occupied by objects, variables and method definitions. The static keyword makes sure that there is only one instance of the concerned method, object or variable created in memory. It is used when one needs to […]
The java.util.ResourceBundle is a library used for internationalization (multiple languages). It is able to return messages as per the default Locale configured for the system. Such a functionality is used when one develops systems to be used all over the world. 1. How it works? The library reads a property file based on the locale and name […]
Final keyword in Java is a modifier used to restrict the user from doing unwanted code or preventing from the code or value from being changed. It is possible to use this keyword in 3 contexts. They are: Final keyword as a variable modifier Final keyword as a method modifier Final keyword as a class […]
Java object Serialization is an API provided by Java Library stack as a means to serialize Java objects. Serialization is a process to convert objects into a writable byte stream. Once converted into a byte-stream, these objects can be written to a file. The reverse process of this is called de-serialization. A Java object is […]
The java.awt library provides 5 basic layouts. Each layout has its own significance and all of them are completely different. Here in this article, we will discuss how to apply any layout to a frame or a panel and also discuss about each layout in brief. The 5 layouts available in the java.awt library are: […]
This article covers 3 ways to read a text file line by line : Java NIO libraries – FileChannel to read the files. It is a non-blocking mode of reading files BufferedReader – Which is a blocking operation i.e it blocks any other read/write request to the file until it has completed the task. Apache […]
The java.awt libraries are set of classes provided by Java in order to draw shapes on a window. The abbreviation AWT stands for Abstract Windowing Toolkit. Today, the library has been converted into a huge set of classes which allows the user to create an entire GUI based application. The visual appearance of these classes […]
This article shows the difference in time taken for similar operations on a String object and StringBuffer object. String being an immutable class, it instantiates a new object each time an operation is performed on it StringBuffer being a mutable class, the overhead of object instantiation during operations is removed. Hence, the time taken for […]
