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Easy Learn Java: Programming Articles, Examples and Tips - Page 38


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Any idea how to lock a Session ID? Ho to prevent its usage again?

Go to all tips in General Java

Question: Any idea how to lock a Session ID? Ho to prevent its usage again?

Answer: You do need to trace session IDs to avoid theirs
repetition if you use our approach to ID constructing from the
tip above. Your IDs always will be unique, since some of data
never repeats (such as Date)



23 comments | Printer Friendly Page  Send to a Friend | Score: 0
Posted by jalex on Wednesday, April 02, 2003 (00:00:00) (4313 reads)

When do I need to use reflection?

Go to all tips in General Java

Question: When do I need to use reflection?

Answer: Reflection is a feature in the Java programming language.
It allows an executing Java program to examine or "introspect" upon itself, and manipulate internal properties of the program. For example, it's possible for a Java class to obtain the names of all its members and display them.
The ability to examine and manipulate a Java class from within
itself may not sound like very much, but in other programming
languages this feature simply doesn't exist. For example, there
is no way in a Pascal, C, or C++ program to obtain information
about the functions defined within that program.

The reflection API represents, or reflects, the classes,
interfaces, and objects in the current Java Virtual Machine.
You'll want to use the reflection API if you are writing
development tools such as debuggers, class browsers, and GUI
builders. With the reflection API you can:
Determine the class of an object.
Get information about a class's modifiers, fields, methods,
constructors, and superclasses.
Find out what constants and method declarations belong to an
interface.
Create an instance of a class whose name is not known until
runtime.
Get and set the value of an object's field, even if the field
name is unknown to your program until runtime.
Invoke a method on an object, even if the method is not known
until runtime.
Create a new array, whose size and component types is not known
until runtime, and then modify the array's components.

Read more about reflection here:
http://developer.java.sun.com/developer/technicalArticles/ALT/Reflection/
http://java.sun.com/docs/books/tutorial/reflect/index.html



4 comments | Printer Friendly Page  Send to a Friend | Score: 4
Posted by jalex on Tuesday, April 01, 2003 (00:00:00) (6580 reads)

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