Sams Teach Yourself Java 2 in 24 Hours

By Rogers Cadenhead

• Table of Contents
  • Copyright
  • About the Author
  • About the Technical Editor
  • Acknowledgments
  • We Want to Hear from You!
  • Reader Services
  • Introduction
  • Hour 1. Becoming a Programmer
  • Hour 2. Writing Your First Program
  • Hour 3. Vacationing in Java
  • Hour 4. Understanding How Java Programs Work
  • Part II: Learning the Basics of Programming
  • Hour 5. Storing and Changing Information in a Program
  • Hour 6. Using Strings to Communicate
  • Hour 7. Using Conditional Tests to Make Decisions
  • Hour 8. Repeating an Action with Loops
  • Part III: Working with Information in New Ways
  • Hour 9. Storing Information with Arrays
  • Hour 10. Creating Your First Object
  • Hour 11. Describing What Your Object Is Like
  • Hour 12. Making the Most of Existing Objects
  • Part IV: Programming a Graphical User Interface
  • Hour 13. Building a Simple User Interface
  • Hour 14. Laying Out a User Interface
  • Hour 15. Responding to User Input
  • Hour 16. Building a Complex User Interface
  • Part V: Creating Multimedia Programs
  • Hour 17. Creating Interactive Web Programs
  • Hour 18. Handling Errors in a Program
  • Hour 19. Creating a Threaded Program
  • Hour 20. Reading and Writing Files
    • Streams
    • Writing Data to a Stream
    • Workshop: Writing Bytes to an MP3 File
    • Summary
    • Q&A
    • Quiz
    • Questions
    • Activities
  • Part VI: Creating Multimedia Programs
  • Hour 21. Using Fonts and Color
  • Hour 22. Playing Sound Files
  • Hour 23. Working with Graphics
  • Hour 24. Creating Animation
  • Part VII: Appendixes
  • Appendix A. Tackling New Features of Java 2 Version 1.4
  • Appendix B. Using the Java 2 Software Development Kit
  • Appendix C. Programming with the Java 2 Software Development Kit
  • Appendix D. Using Sun ONE Studio
  • Appendix E. Where to Go from Here: Java Resources
  • Appendix F. This Book's Web Site

Questions

1. Which of the following techniques can be used to convert an array of bytes into a string?
   1. Call the array's toString() method.
   2. Convert each byte to a character, then assign each one to an element in a String array.
   3. Call the String() constructor method with the array as an argument.
2. What kind of stream is used to read from a file in a Java program?
   1. an input stream
   2. an output stream
   3. either
3. What method of the File class can be used to determine the size of a file?
   1. getSize()
   2. read()
   3. length()

Answers

1. c. You can deal with each byte individually, as suggested in answer b., but you can easily create strings from other data types.
2. a. An input stream is created from a File object or by providing a filename to the input stream's constructor method.
3. c. This method returns a long representing the number of bytes in the stream.

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