Java Concepts By Cay Horstmann - Part6

Couple of Days back i started reading Java Concepts 5th Edition By Cay Horstmann.

Nice book written by Cay Horstmann.

I wanted to share few quotations from the next two (11-12) chapters.

1) When reading text files, use the Scanner class.

2) When writing text files, use the PrintWriter class and the print/println methods.

3) You must close all files When you are done processing them.

4) A File object describes a file or directory.

5) You can pass a File object to the constructor of a file reader, writer, or stream.

6) To signal an exceptional condition, use the throw statement to throw an exception object.

7) When you throw an exception, the current method terminates immediately.

8) There are two kinds of exceptions: checked and unchecked. Unchecked exceptions extend the class RuntimeException or Error.

9) Checked exceptions are due to external circumstances that the programmer cannot prevent. The compiler checks that your program handles these exceptions.

10) Add a throws specifier to a method that can throw a checked exception.

11) In a method that is ready to handle a particular exception type, place the statements that can cause the exception inside a try block, and the handler inside a catch clause.

12) It is better to declare that a method throws a checked exception than to handle the exception poorly.

13) Once a try block is entered, the statements in a finally clause are guaranteed to be executed, whether or not an exception is thrown.

14) You can design your own exception types—subclasses of Exception or RuntimeException.

15) The life cycle of software encompasses all activities from initial analysis until obsolescence.

16) A formal process for software development describes phases of the development process and gives guidelines for how to carry out the phases.

17) Many software engineers break the development process down into the following five phases:

• Analysis
• Design
• Implementation
• Testing
• Deployment

In the analysis phase, you decide what the project is supposed to accomplish; you do not think about how the program will accomplish its tasks. The output of the analysis phase is a requirements document, which describes in complete detail what the program will be able to do once it is completed. Part of this requirements document
can be a user manual that tells how the user will operate the program to derive the promised benefits. Another part sets performance criteria—how many inputs the program must be able to handle in what time, or what its maximum memory and disk storage requirements are.

In the design phase, you develop a plan for how you will implement the system. You discover the structures that underlie the problem to be solved. When you use object-oriented design, you decide what classes you need and what their most important methods are. The output of this phase is a description of the classes and
methods, with diagrams that show the relationships among the classes.

In the implementation phase, you write and compile program code to implement the classes and methods that were discovered in the design phase. The output of this phase is the completed program.

In the testing phase, you run tests to verify that the program works correctly. The output of this phase is a report describing the tests that you carried out and their results.

In the deployment phase, the users of the program install it and use it for its intended purpose.

18) The waterfall model of software development describes a sequential process of analysis, design, implementation, testing, and deployment.

19) A prototype is a small system that shows some aspects of the final system

20) Extreme Programming is a development methodology that strives for simplicity by removing formal structure and focusing on best practices.

21) Inheritance (the is-a relationship) is sometimes inappropriately used when the has-a relationship would be more appropriate.

22) Aggregation (the has-a relationship) denotes that objects of one class contain references to objects of another class.

23) Dependency is another name for the "uses" relationship.

24) You need to be able to distinguish the UML notations for inheritance, interface implementation, aggregation, and dependency.

25) Use javadoc comments (with the method bodies left blank) to record the behavior of classes.


About the Author

Cay Horstmann grew up in Northern Germany and attended the Christian-Albrechts-Universität in Kiel,a harbor town at the Baltic sea. I received a M.S. in computer science from Syracuse University , and a Ph.D. in mathematics from the University of Michigan in Ann Arbor. I now teach computer science at San Jose State University . In my copious spare time I write books and articles on Java and consult on internet programming.