Overview

The cucs package for Java has been implemented at Clemson University to facilitate the use of Java by students. The services provided by classes in the cucs package make it easier to learn how to program in Java by eliminating the need to learn many of the details and concepts that are inherent in the standard Java libraries. For example, the cucs package provides classes to do basic stream input by reading integers, reals, and sequences of nonblank characters in addition to the character- and line-oriented input provided in package java.io. There also are classes that make it much easier to create GUIs than it is when only package java.awt is used.

The classes that are currently provided in the cucs package are:

• BasicDataReader - A BasicDataReader object provides the ability to read from a stream (standard input or a text file) by requesting the next word, integer, double, or line from the stream. (This is similar to stream input in other languages such as C, C++, Ada, and Pascal.) The methods of the BasicDataReader class throw no exceptions. Methods are provided to detect whether end-of-file or an error occurred on the last input operation.

• DataReader - A DataReader object provides the ability to read from a stream (standard input or a text file) by requesting the next word, integer, double, or line from the stream. (This is similar to stream input in other languages such as C, C++, Ada, and Pascal.) Exceptions are thrown to indicate end of file or invalid data.

• DataException - A DataException is thrown when bad input data, such as an invalid string of characters for an integer or double, is encountered in an input stream.

• BasicDataWriter - A BasicDataWriter object provides text (byte) stream output without exceptions. An output value is converted to String if needed, and written to the output file as a stream of bytes. No separator is written between successive output items. An output item can be an integer (int, long, etc.), floating-point (double, float), or String value. The output stream can be standard output or another file. Methods are provided to detect whether an operation failed and to close the file.

• DataWriter - A DataWriter object provides the same operations as for BasicDataWriter, but exceptions are thrown for errors.

• Formatter - A Formatter object provides formatting operations for numerical (integer and floating-point) and string data. A value can be formatted as a string of any length, using left, center, or right justification, and any nonnegative precision for floats.

• GUI - The GUI class is a superclass for simple GUI application windows. It provides the functions of class WindowBase, plus it also facilitates the management of buttons, text fields, and text areas in an application GUI window.

• IntField - An IntField object is an input/output field in a GUI that contains an int value. There are methods for setting and retrieving the int value contained in an IntField.

• DoubleField - An DoubleField object is an input/output field in a GUI that contains a double value. There are methods for setting and retrieving the double value contained in an DoubleField.

• WindowBase - The WindowBase class extends the Java AWT Frame class. Thus it is intended to serve as the superclass for an application window class. It provides basic window management functions, such as disposing of the window when it is quit and terminating the program, and it also provides the inset values for the borders of the window.

• BasicInputDataReader - This class has been renamed BasicDataReader, but it has been retained for upward compatibility.

• InputDataReader - This class has been renamed DataReader, but it has been retained for upward compatibility.

• BasicOutputDataWriter - This class has been renamed BasicDataWriter, but it has been retained for upward compatibility.

• OutputDataWriter - This class has been renamed DataWriter, but it has been retained for upward compatibility.

Using the cucs package

To use (import) the cucs in a Java program, the cucs class library must be in the class path. On the Clemson Department of Computer Science network this is done by adding /pub/faculty/turner/javalib to the CLASSPATH variable (which can be done, for example, by appending the command

setenv CLASSPATH ${CLASSPATH}:/pub/faculty/turner/javalib

Versions

(The last version listed is the current version.)

Initial version

Class BasicInputDataReader

Class InputDataReader

Class DataException

Class WindowBase

Version 1.0

Added class Formatter

Version 1.1

Added class BasicOutputDataWriter

Added class OutputDataWriter

Version 1.1.1

Added flush(), checkError(), and writeLine methods to output writers.

Fixed problem of ignoring blanks on readLine in input readers.

Changed the readers (BasicInputDataReader, InputDataReader) to avoid buffering on System.in to improve the interactive characteristics on Dos

Version 1.1.2

Added the BasicDataReader, BasicDataWriter, DataReader, and DataWriter classes (renamed from BasicInputDataReader, BasicOutputDataWriter, InputDataReader, and OutputDataWriter).

Additional information

• Basic documentation

• Examples

• Source code

• Installing cucs