The Classloaders in Java dynamically load Java classes into the Java Virtual Machine. Usually classes are only loaded on demand. By default, Java uses three class loaders, when JVM starts. Bootstrap classloader Extension classloader System classloader Following figure shows the role of each ClassLoader:- The ClassLoaders in Java works on…
We will see the basic data types in Java. We will also write a simple program to assign values to different data types and print their values. Primitive data types byte byte is a 8 bit signed two’s complement integer. Can stores values from -128 to 127. byte bt =…
Here we will write a simple program in Java. Pre-requisites :- Java installed on your system. Download Java JDK and add JAVA_HOME environment variable to your system. Add ‘JAVA_HOME/bin’ path to your system’s PATH variable. IDE for Java- like eclipse. Assuming that you are done with the above requirements. Lets…
We can use reflection feature of Java to invoke methods of a Java class. Suppose we have a class Employee, with getter methods for fields – name, age sex, salary, city. A user may want to send an array of property names to a method and based on the input…
Sometimes we may need to read data from a file in a Java class and this file lies in the same package as that of the class. Different Java classes may need to read data from a file lying in their own package. If all the files in different packages…
SSH SSH (Secure Shell) provides support for secure remote login, secure file transfer, and secure TCP/IP and X11 forwarding. SSH uses a client-server model for – 1. Establishing a secured connection between two parties, 2. Authenticating the two parties, and 3. Encrypting the data transmissions between the two parties. To…
BlockingQueue A BlockingQueue supports operations that :- 1. wait for some element to be available in the queue when retrieving an element. 2. wait for space to become available in the queue when storing an element. We will see implementation of a simple Producer-Consumer using BlockingQueue. We will be using…
ArrayList ArrayList in Java implements List Interface. It accepts even null elements. ArrayList is not synchronized and therefore external synchronization is required while working with ArrayList in Multi-threaded environments. We will see how to add elements and search elements from an ArrayList. Adding elements to an ArrayList is straightforward. Searching…