The "struts-logic" tag library contains tags that are useful in managing conditional generation of output text, looping over object collections for repetitive generation of output text, and application flow management.
Introduction
The Logic library supplies tags that are useful for manipulating presentation logic without the use of scriptlets.
Logic Tag Functionality
The functionality of the logic tags can be divided into four groups:
Value Comparisons - The purpose of these tags is to print out the body of the tag if the comparison evaluates to true.
equal, notEqual
greaterEqual , lessEqual
greaterThan , lessThan
Substring Matching - The purpose of these tags is to match substrings inside of other Strings
match , notMatch
Presentation Location - The purpose of these tags is to change the location of the presentation page
forward
redirect
Collection Utilities -The purpose of these tags is to handle Collections
iterate
Java JDBC Prepared statements are pre-compiled SQL statements. Precompiled SQL is useful if the same SQL is to be executed repeatedly, for example, in a loop. Prepared statements in java only save you time if you expect to execute the same SQL over again. Every java sql prepared statement is compiled at some point. To use a java preparedstatements, you must first create a object by calling the 
Lazy setting decides whether to load child objects while loading the Parent Object.You need to do this setting respective hibernate mapping file of the parent class.lazy = true (means not to load child)By default the lazy loading of the child objects is true. This make sure that the child objects are not loaded unless they are explicitly invoked in the application by calling getChild() method on parent.In this case hibernate issues a fresh database call to load the child when getChild() is actully called on the Parent object.But in some cases you do need to load the child objects when parent is loaded. Just make the lazy=false and hibernate will load the child when parent is loaded from the database.
