Redirecting logging to a file

In this post I will explain how to program the logger to log messages to a file instead of logging to console. Below is the code Main code 1 package Logging; 2 3 import java.io.IOException; 4 import java.util.logging.FileHandler; 5 import java.util.logging.Logger; 6 7 public class LoggingDemo2 { 8 public static void main(String[] args) throws IOException…… Continue reading Redirecting logging to a file

Java logging simple example

This post explains java logging with simple example. Main code 1 package Logging; 2 3 import java.io.IOException; 4 import java.util.logging.Logger; 5 6 public class LoggingDemo1 { 7 public static void main(String[] args) throws IOException { 8 Logger logger = Logger.getLogger(“logger1”); 9 logger.info(“Hello my name is Mathew”); 10 logger.warning(“Hello my name is Mathew”); 11 logger.config(“Hello my…… Continue reading Java logging simple example

Quartz Simple Example

Quartz schedular framework can be used to schedule jobs. This post explains how we can use it with a simple example. We need the below jars 1) c3p0-0.9.1.1.jar 2) log4j-1.2.16.jar 3) quartz-2.2.3.jar 4) quartz-jobs-2.2.3.jar 5) slf4j-api-1.7.7.jar 6) slf4j-log4j12-1.7.7.jar log4j.xml file in the classpath with the below configurations log4j.xml <?xml version=”1.0″ encoding=”UTF-8″?> <!DOCTYPE log4j:configuration SYSTEM “log4j.dtd”>…… Continue reading Quartz Simple Example

Global Scope and Engine Scope Bindings

This post explains about bindings and how we can use them to pass java objects to the script code. Java Scripting API provides map data structure which can be accessed, modified using Bindings Interface. The map entry’s key matches with the variable name in the script and their value can be a primitive value or…… Continue reading Global Scope and Engine Scope Bindings

Default Interface Example

Java 8 introduces a new feature called Default Interface. This feature allows interface creator to provide default implementations for methods, so that concrete classes that implementing the interface don’t have to provide implementations for those methods. The below code gives you an example of how to create default interface and how to use them. Interface…… Continue reading Default Interface Example

Creating a file archiver in zip format

This post explains how to create file archiver in WinZip format. WinZip is a file archiver and compression tool. Whenever a zip file is created by default the file is compressed and archived together in a single file. We can change the default behaviour (i.e., compression) by setting the level property in ZipOutputStream. The below…… Continue reading Creating a file archiver in zip format

Creating a zip file of a folder with CRC32 checksum

This post explains how to create a zip file of a folder (also containing sub folders) with CRC32 checksum. The below code is similar to the previous post “Creating zip file of a folder” with minor change in main method. The main method code snippet from the previous post as shown below File folder =…… Continue reading Creating a zip file of a folder with CRC32 checksum

Executing compiled script

In the previous posts under “Java Scripting”, we used ScriptEngine eval method to execute scripts stored in a string variable or file. The ScriptEngine’s eval methods takes the script compiles to intermediate code and execute it immediately. If we have a script which has to be executed repeatedly, then instead of compiling and executing it…… Continue reading Executing compiled script

Combining Predicates

This post explains how we can combine two or more predicates using logical operations as mentioned below 1) and 2) or 3) negate Below is an example Person package Function; public class Person { private String ssn; private String fname; private String lname; private String description; private int age; public String getSsn() { return ssn;…… Continue reading Combining Predicates