Java J2ee Planet

What is Spring? Spring is a framework that resolves common problems in JEE architecture.  It is a very light-weight and open source framework because of it's POJO model. It is called as modular framework, since it comes as diffrent modules(we will discuss about these modules in below sections). We can use all modules to develop application or we can use only one module, whichever we required. Spring is called as non-invasive framework. It will not compell a developer to extend any of it's calss or implement any of it's interfaces, where Struts framework forces a developer to extend its Action class. i.e. Struts is said to be invasive frameowrk. Managing business objects and encouraging practices such as programming interfaces rather than classes is a consistent way of using Spring.  Spring addresses all architectural tiers with basic building block by utilizing IoC.  Unique data access abstraction including abstraction of JDBC framework improves the productivity an

Ajax (asynchronous JavaScript and XML) is a technology that allows for for highly-interactive and responsive browser-based applications. By leveraging the XMLHttpRequest object, seamless communication with the server can be achieved for a smooth and dynamic user experience. If you've ever wanted to learn about Ajax , there are many sites out there that'll help you "grok" Ajax and the various technologies surrounding it. Here are 20 top-notch websites that cover the subject of Ajax . 1. Ajax resource center (developerWorks) developerWorks, a resource center for developers and IT professionals by IBM, has a dedicated Ajax resource center that hosts plenty of tutorials on Ajax. developerWorks tutorials are in-depth and lengthy, and you can learn a variety of information and techniques from them such as creating RIA applications with jQuery and Ajax , learning about Ajax security tools , and building an Ajax-based chat system .

1.It separates the working/functional code from the error-handling code by way of try-catch clauses. 2.It allows a clean path for error propagation. If the called method encounters a situation it can't manage, it can throw an exception and let the calling method deal with it. 3.By enlisting the compiler to ensure that "exceptional" situations are anticipated and accounted for, it enforces powerful coding. 4.Exceptions are of two types: Compiler-enforced exceptions, or checked exceptions. Runtime exceptions, or unchecked exceptions. Compiler-enforced (checked) exceptions are instances of the Exception class or one of its subclasses — excluding the RuntimeException branch. 

There are four JDBC driver types. Type 1: JDBC-ODBC Bridge plus ODBC Driver: The first type of JDBC driver is the JDBC-ODBC Bridge. It is a driver that provides JDBC access to databases through ODBC drivers. The ODBC driver must be configured on the client for the bridge to work. This driver type is commonly used for prototyping or when there is no JDBC driver available for a particular DBMS. Type 2: Native-API partly-Java Driver: The Native to API driver converts JDBC commands to DBMS-specific native calls. This is much like the restriction of Type 1 drivers. The client must have some binary code loaded on its machine. These drivers do have an advantage over Type 1 drivers because they interface directly with the database.