faruk's learning journey

if you are developing a JEE applications, if haven't yet, one day you might face exceptions due to loading wrong SAX implementation. and if you are producing an ear then it makes more difficult to understand reasons behing. think that you are using jdk 1.6 and want to use SAX in your application. it is very easy, since jdk1.6 contains sax implementation without anything you can. if you decided to use apaches xerces imp. , then you must put related jar to your ears classpath. but how these additional classes being picked up, despite exact same classes are in jdk's classpath. basic rule in java whist loading a class is, if you have a parent classloader then delegate this loading action to parent classloader. if it can not find then try to load class by own. factory finder in SAX Specification looks system parameter, then JAVA_HOME/lib/jaxp.properties, then META-INF/services/javax.xml.parsers.SAXParserFactory respectively. in such case like using an application server li...