SUNY Geneseo Department of Computer Science

Text Files in Java

Previous Lecture

Misc

Exam 1 is this Friday (Oct. 10)

• Basics of design, theory, experimentation, and recursion, induction, recurrences
• Open book, open notes, open computer
• 3 - 5 short-answer questions (algorithms, proofs, paragraphs, etc.)
• Whole class period
• Sample test will be on Web

Questions?

Reading files for homework 1

Text differs from arbitrary data

• Division into lines
• Contents are always characters

Generic code to get text from a file

1. Open reader to file
2. Read strings or characters from reader

Step 1

        FileReader r = new FileReader( "SimpleHunt.txt" );
        BufferedReader in = new BufferedReader( r );

or

        BufferedReader in = new BufferedReader( new FileReader( "SimpleHunt.txt" ) );

Step 2

        String lineOfText = in.readLine();
        RobotRoom room = new RobotRoom( lineOfText );

Directories and Path Names

• Project builder: current directory when program runs is "build" directory inside the project directory
• Path name: series of directories from root to what you want
  • e.g., /Users/LabUser/myFile

Exceptions

• Bad things sometimes happen to good programs
• "Bad thing" "throws" an exception
• Causes control transfer out of part of program that detects error, to some other part - "Exception handler"

    try {
        ... code that might throw exception
    }
    catch ( Exception e ) {
        ... code to handle exceptions
    }

Next

Recurrence relations

Read Section 7.2.1

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