CS506 Final Term Solved Subjective by Junaid

Q1. Stages of servlet life cycle:

1. Initialize
2. Destroy
3. Service

2. Tomcat Standard directory structure

3. Draw backs of page-centric Approach:

The page centric approach has a lot of drawbacks such as the code becomes a mixture of presentation, business and data access logic. The maintenance and upgradation of the application becomes nightmare (difficult).Scaling of such kind of application is also difficult and lots of code is get duplicated.

4. Html comments syntax

<!--comments-->

5. JSP comments syntax

<%--comment text--%>

6. Response redirection forms:

1. Sending a standard redirect
2. Sending a redirect to an error page

7. Primitive data types for java · boolean, byte · 1 byte · char, short · 2 bytes · int, float · 4 bytes · long, double · 8 bytes · 8. Exception handling in java

Java handles exceptions via 5 keywords. Try, catch, finally, throw and throws.

9. Stream classification based on functionality

1. Node stream:

are those which connect directly with data source/sink and provides basic functionality to read/write data from source/sink . FileReader fr = new FileReader(“input”);

2. Filter stream:

sit on top of node stream or chain with other filter stream and provide some additional functionality e.g compression, security etc. Filter streams take other stream as input. BufferedReader bt = new BufferReader(“fr”);

10. Some well-known ports:

FTP works on port 21 HTTP works on port 80 TELNET works on port 23

11. Socket:

A socket is bi-directional communication channel between hosts.

12. Multithreading:

Multithreading is the ability to do multiple things at once with in same application.

13. Thread:

A thread sometimes called an execution context or a lightweight process is a single sequential flow of control within a program.

14. Creating Thread in java:

1. Using interface
2. Using inheritance

15. Thread priority scheduling:

The java runtime environment supports a very simple, deterministic scheduling algorithm called fixed-priority scheduling. This algorithm schedules threads on the basis of their priority relative to other Runnable threads.

16. URL rewriting

The following URLs have been rewritten.

Extra path information:

17. Parts of Http response:

Result code Header Fields Body

Q18. Name of Arithmetic Operator?

Operator · Example · Description

Addition X+Y Adds together two values Subtraction X-Y Subtracts one value from another Multiply X*Y Multiple two values Division X/Y Divide one value by other Module X%Y Return the division remainder Increment ++X Increase the value of a variably by 1 Decrement --X Decrease the value of a variably by 1

Logical Operator:

Operator

Logical and Logical or Logical not

Q19. Alternative of inheritance in Java?

Answer: Delegation can be an alternative to inheritance. Delegation means that you use an object of another class as an instance variable, and forward messages to the instance.

Q20. Names of Tomcat directory?

Answer: bin – startup, shutdown and other scripts and executables commoncommon classes that Catalina and web applications can use conf – XML files and related DTDs to configure Tomcat logs – Catalina and application logs server – classes used only by Catalina shared classes shared by all web applications