There's frameworks out there (e.g. Struts , Spring and Hibernate) to reduce the effort , but Compiere goes one step further - it gives you a complete ERP (Enterprise Resource Planning) and CRM (Customer Relationship Management) solution in a box , which you can then customize for your end client.
Compiere is very good ,as befits a project that is consistently in the top 10 on sourceforge. So , if you have any interest in Java and Oracle , you should check it out at www.compiere.org. Worked with this product in my days with firstpartners.net in Dundalk , Ireland , and good as it was then , the product has matured a lot more (included Database independence)