Programming For Future

There has always been a basic requirements in website or web applications that the menu bar must be dynamic and all menu items should be appeared under their respected parent. Here, if you are managing the menu items in database, then you have to retrieve all menu items in the way that each menu item must have its proper position in menu tree. here you could use just a loop because you don't know that how many menu times are going to be added in future. So, Here is the example in which I am using the recursion approach for creating the menu tree dynamically for any level. there is the database table "menu_items" having the columns id , name and parent . Parent column will have the id of the parent menu as foreign key. You can increase some more columns as per your requirements like label, url and so on. There are some values already there for testing purpose.     import java . sql . Connection ; import java . sql . DriverManager ; import java . sql . Re...

Creating Restful web services in java is not a difficult task. You just use some annotation to expose you methods as web service end points. All annotations those turn your method into web services are in javax.ws.rs package. To host you web service, you can use tomcat or any web server. One thing you need to do is, configure the jersey ServletContainer servlet in web.xml for the particular url pattern. See the following example depicting the calculator service. package  pack; import  java.net. URI ; import  java.net. URISyntaxException ; import  javax.ws.rs.GET; import  javax.ws.rs.POST; import  javax.ws.rs.Path; import  javax.ws.rs.PathParam; import  javax.ws.rs.Produces; import  javax.ws.rs.core.Response; @ Path ( "/cal" ) public   class  CalculatorResource  {     @GET     @ Produces ( "text/plain" )      public   String   getDate () ...

Spring framework is the platform which supports for developing java applications using its infrastructure (Physical and organizational structures). Spring allows you to develop application with simple plan old java objects (POJO). Spring takes care of managing objects and their lifecycle. This framework provides the stage for your objects to play their role and all dependencies the objects depend on are provided at that time whenever required. Spring framework integrates your objects to create an application and make them independent from each other. Spring connects all objects being maintained by it by injecting their reference in each other as per requirements. Spring able to manage various common requirements for your application like database connection, transactions, emailing, orm, aop etc. For example, if you imagine a calculator application which has the following objects to accomplish its functionality: Keyboards Display Adder Subs tractor Divider Mult...

 spring-dispatcher-servlet.xml <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <mvc:annotation-driven /> <context:component-scan base-package="myproject" /> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name...