Yogesh's Tech Blog

      Please refer previous post for Singleton Designing Pattern . Concurrency is the one of the major issues with singleton designing pattern.       There will be multiple client accessing same singleton resource instance. If this resource is mutable then concurrency need to be taken care . Example from previous post is being used here. 1: package demo.singleton; 2: import java.util.concurrent.locks.ReadWriteLock; 3: import java.util.concurrent.locks.ReentrantReadWriteLock; 4: /** 5: * Singleton Resource Class 6: * @author Yogesh 7: */ 8: public class SingletonResource { 9: private static SingletonResource resorce = null ; 10: int count; 11: private ReadWriteLock writeLock = new ReentrantReadWriteLock(); 12: 13: public static SingletonResource getInstance(){ 14: if (resorce == null ){ 15: synchronized (SingletonResource. class ){ 16: if (res...

Latest version of Java Enterprise Edition is focused on eae of development and simplicity. Key goals of this version are Extensibility – supports for additional technologies and frameworks Profiles – support for creating custom profiles based on application scope or requirement. Pruning New Features introduced in this edition are Simplified EJB 3.1 No local business interface – one step further from EJB 3.0 specification, EJB 3.1 specifications removes mandatory business interface Singleton EJB – to share application wide data and support concurrent access. EJB 3.1 can be part of war file directly without creating a separate jar file EAR >>       WAR >>             JSP/Static Pages             WEB_INF >>         ...

      JDeveloper 10g comes with UI based web service assembler. It converts simple java class to web service. You can customize web service assembling using Custom Serializer in case Service class accepts pojo class as parameters or return it. This post explains creating web service from simple java class. It is considered that you have gone through previous posts – JAXB by Jdeveloper and XML Document by Jdeveloper . So you have xml schema , xml document and set of java classes generated by JAXB compilation Here is step by step approach 1.    Code a CustomSerializer , it has to implement SOAPElementSerializer and override deserialize and serialize methods. Sample code is as below package jaxb.serializer; import javax.xml.bind.JAXBException; import oracle.webservices.databinding.SOAPElementSerializer; import javax.xml.soap.SOAPFactory; import javax.xml.soap.SOAPException; import javax.xml.soap.SOAPElement; import ja...

      Jdeveloper 10g comes with JAXB1.0 tool .  This tool makes XML programming just one click away.This tutorial explains using JABX compilation tool of JDeveloper. In previous post we have seen handling of XML schema and XML document . You can refer the same as prerequisite for this post . Here is the step by step approach 1. Compile xml schema 2. Mention package and Test class 3. This will generate set of java classes under mentioned java package.You will notice one interface and implementation for each complex type or node. ItemType.java and ItemTypeIMpl.java get generated for  complex types ItemType. As we had selected Main class for generation, it creates Main class for testing JAXB compilation.           4. Here is the marshalling and un-marshalling code . [ refer this post for JAXB Coding ] package jaxb.test; import java.io.File; import javax.xml.bind.JAXBContext; import javax....

This tutorial explain creating xml schema from scratch and creating xml document from it as well. Jdeveloper 10g has a very easy visual editor for creating xml schema as well as xml document. It is considered that you have basic knowledge of schema. Here are step by step approach 1.Create new project and them create new XML schema   2.By default, a simple schema header tag  and an example element   3. Here we are going to construct schema for an Order xml document like  Order>>Item_list>>Item . A order will have id,description,shipTo address and list of items. To construct such structure we will have three complex type order_type, item_type and order_list_type. So create order_type complex type by drag and drop Complex Type component and edit properties   4. Now drag and drop sequence component to complex component 5.  now drag and drop element components one by one and edit the properties   6. There ...