Why do you migrate from ASP to JSP/Servlet ?

Both ASP and JSP technologies let developers separate content generation from layout by accessing components from the page. ASP supports the COM model, while JSP technology provides components based on JavaBeansTM technology or JSP tags.

Extensible JSP Tags

The first difference apparent to any page author are the JSP tags themselves. While both ASP and JSP use a combination of tags and scripting to create dynamic Web pages, JSP technology enables developers to extend the JSP tags available. JSP developers can create custom tag libraries, so page authors can access more functionality using XML-like tags and depend less on scripting. With custom tags, developers can shield page authors from the complexities of page creation logic and extend key functions to a broader range of authors.

Reusability Across Platforms

Developers will also notice the focus on reusability. The JSP components (Enterprise JavaBeansTM, JavaBeans, or custom JSP tags) are reusable across platforms. An Enterprise JavaBean component accessing legacy databases can serve distributed systems on both UNIX and Microsoft Windows platforms. And the tag extension capability of JSP technology gives developers an easy, XML-like interface for sharing packaged functionality with page designers throughout the enterprise.

This component-based model speeds application development because it enables developers to:

The Java Advantage

JSP technology uses the Java language for scripting, while ASP pages use Microsoft VBScript or JScript. The Java language is a mature, powerful, and scalable programming language that provides many benefits over the Basic-based scripting languages. For example, the Java language provides superior performance to the interpreted VBScript or JScript languages. Because they use Java technology and are compiled into Java servlets, JSP pages provide a gateway to the entire suite of server-side Java libraries for HTTP-aware applications.

The Java language makes the developer's job easier in other ways as well. For example, it helps protect against system crashes, while ASP applications on Windows NT systems are susceptible to crashing. The Java language also helps in the area of memory management by providing protection against memory leaks and hard-to-find pointer bugs that can slow application deployment. Plus, JSP provides the robust exception handling necessary for real-world applications.

Easier Maintenance

Applications using JSP technology are easier to maintain over time than ASP-based applications.

Scalability in the Enterprise

The Java 2 Platform, Enterprise Edition (J2EE) is the Java architecture for developing multitier enterprise applications. As part of J2EE, JSP pages have access to all J2EE components, including JavaBeans and Enterprise JavaBeans components and Java servlets. JSP pages are actually compiled into servlets, so they have all of the benefits of these flexible, server-side Java applications. The J2EE platform containers manage the complexities of enterprise applications, including transaction management and resource pooling.

JSP pages have access to all of the standard J2EE services, including:

Through J2EE, JSP pages can interact with enterprise systems in many ways. J2EE supports two CORBA-compliant technologies: Java IDL and RMI-IIOP. With Enterprise JavaBeans technology, JSP pages can access databases using high-level, object-relational mappings.

Finally, because JSP technology was developed through the Java Community Process, it has wide support from tool, Web server and application server vendors. This enables users and partners take a best-of-breed approach, selecting the best tools for their specific applications while protecting their investment in code and in personnel training.

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