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The hsa package - Details

• Introduction
• hsa Applications - Running Outside VisualAge for Java
• hsa Applications - Setting Options
• hsa Applications
  • Submit
  • PrintFiles
  • PrettyPrint
• hsa Classes
  • Console
    • Constructors and General Methods
    • Graphics Methods
    • Text Input and Output Methods
    • Example Program
  • TextConsole
    • Constructors and General Methods
    • Text Input and Output Methods
    • Example Program
  • Stdin
    • Introduction
    • Methods
    • Example Program
  • Stdout
    • Introduction
    • Methods
    • Example Program
  • TextInputFile
    • Introduction
    • Constructors and Methods
    • Example Program
  • TextOutputFile
    • Introduction
    • Constructors and Methods
    • Example Program
  • FatalError
    • Introduction
    • Constructors and Methods
    • Example Program
  • Message
    • Introduction
    • Constructors and Methods
    • Example Program
  • Status
    • Introduction
    • Constructors and Methods
    • Example Program

Introduction

The classes make it easier for users to begin writing programs that explore the basic concepts of computer science before coming to terms with the input and output methods of the Java class library.

To ensure the easiest possible transition from using the hsa package to using only the Java class library, wherever possible we have made the graphics methods in the Console class identical to those in the Java Graphics class. The print and println methods of the Console, Stdout, and TextOutputFile are also the same as those in the Java PrintWriter class. In a number of cases the classes in the hsa package contain extra methods.

To use the hsa classes, the following line must appear in the class header:

        import hsa.*;
  

Executing the hsa Applications

If you wish to be able to execute the programs from the DOS command line, you must obtain the latest version of Sun's Java Runtime Environment (JRE), which includes a Java Virtual Machine, free of charge from www.javasoft.com. See the installation instructions for information on where to copy the hsa directory and Sun's JRE for information on the CLASSPATH environment variable.

To execute any of these program from Sun's JRE, you must enter DOS, move to the directory containing the files to be submitted, printed, or paragraphed, and type:

        java hsa.Application-Name
  

Failure of the JRE to find the program indicates that the hsa directory has not been correctly placed in one of the directories listed in the CLASSPATH. Check the documentation for Sun's JRE for more information on the CLASSPATH variable.

hsa Applications - Setting Options

The simplest way is to specify the options on the command line. This is done by entering the option after the name of the program, for example,

        java hsa.Submit -nobold -noitalic
  

The second way is to change the options in the Options dialog box. Once you have started the program, each of the hsa application programs comes up with an Options dialog box which has checkboxes, radio buttons, and text fields for the basic options you can select. It also has a menu labelled "Options". The Options menu allows you to get information about the program, see only the basic options, see the advanced options, and save the options so the current set of options become the default values the next time the program is run.

The third way to enter options is to edit a file called hsa.config located in the your home directory. This file is read for options every time any of the hsa programs are executed and options are saved to this file when the user selects the Save Options menu item. There is a section in the file for each of the three applications. Each section is prefaced with the line "[Submit]", "[PrettyPrint]" or "[PrintFiles]". An example hsa.config file might look like:

        [Submit]
        -nobold
        -noitalic
        [PrettyPrint]
        -indent 2
  

Here is the list of all the available options. The default options are listed in bold face. Items in curly braces can be included zero or more times.

-program classname		Submit
	Sets the program to be submitted to classname. If this option and -nooptions is set, the initial Submit dialog box does not appear.
-sourcedir sourcedirectory		All
	Sets the initial directory to sourcedirectory for the Select Source Files (Submit), Select Files to Print (PrintFiles), or Select Files To Indent (PrettyPrint) dialog box. If no option is specified, the initial directory is set to the current directory.
-source sourcefile {sourcefile}		All
	Sets the source files to be printed (Submit, PrintFiles) or paragraphed (PrettyPrint) to be the files specified. If this option is used, the Select Source Files (Submit), Select Files to Print (PrintFiles), or Select Files To Indent (PrettyPrint) dialog box does not appear.
-inputdir inputdirectory		Submit
	Sets the initial directory to inputdirectory for the Select Input Files dialog box. If no option is specified, the initial directory is set to the last directory used in the Select Source Files dialog box.
-input {inputfile}		Submit
	Sets the input data files to be used to run the submitted program. If this option is used, the Select Input Files dialog box does not appear. You do not need to specify any inputfile, in which case the submitted program is run once with no input.
-echo		Submit
	Echoes input read from file into the program's output.
-noecho		Submit
	Does not echo input read from the file into the program's output.
-indent		Submit, PrintFiles
	Indents the programs using PrettyPrint before printing them.
-noindent		All
	Does not indent the programs before printing them.
-print		Submit, PrintFiles
	Prints to the printer (see -preview for sending all output to a window instead).
-preview		Submit, PrintFiles
	Sends all output to a window rather than to the printer. This option is useful for reviewing the results of a Submit without wasting paper.
-bold		Submit, PrintFiles
	Prints Java keywords in bold face when printing programs.
-nobold		Submit, PrintFiles
	Does not print Java keywords in bold face when printing programs.
-italic		Submit, PrintFiles
	Prints identifiers in italics when printing programs.
-noitalic		Submit, PrintFiles
	Does not print identifiers in italics when printing programs.
-defaultmargin		Submit, PrintFiles
	Makes printing assume that Java has set the printer margins correctly. Due to some irregularities in the way Java (all environments) does printing, there is no way to know whether the upper-left corner of the printing area is the upper-left corner of the page, or the upper-left corner of the printable area. If your printouts are being cut off on the top and left sides, use the -margin option to set the margins.
-margin {leftmargin, topmargin}		Submit, PrintFiles
	Causes Submit and PrintFiles to add their own margins when printing. leftmargin and topmargin are specified in inches. If they are not specified (leftmargin and topmargin are optional), the left and top margins are set to 0.35". If your printouts are being cut off on the top and left sides, use this option to set the margins. If necessary, specify leftmargin and topmargin to get printing to be placed correctly on the page.
-indentsize indentSize		All
	Sets the size of each indentation when paragraphing to indentSize spaces. This defaults to 4. This option is only relevant if the -toother option is selected (which it is by default).
-usetabs		PrettyPrint
	Converts groups of 8 spaces into tabs when the paragraphed program is saved. This option is only relevant if the -toother option is selected (which it is by default).
-usespaces		PrettyPrint
	Does not converts spaces into tabs.
-fromva (from va)		All
	Makes hsa programs assume that source files have been exported from the VisualAge for Java environment and that tabs are set at 0.25" apart.
-fromother (from other)		All
	Makes hsa programs assume that source files have come from other environments and that tabs are set 8 spaces apart.
-tova (to va)		PrettyPrint
	Saves PrettyPrinted (indented) file in format suitable for importation into VisualAge for Java. Each level of indentation is one tab, and tabs are assumed to be 0.25" apart. Assumes lines are 70 columns across.
-toother (to other)		PrettyPrint
	Saves PrettyPrinted (indented) file in a format suitable for printing or use in another environment. Indentation is specified by the -indentsize option and spaces are converted to tabs if the -usetabs option is specified. Tabs are assumed to be 8 spaces apart. Assumes lines are 80 columns across.
-compact		All
	Leaves the opening curly brace at the end of a line.
-expanded		All
	Places an opening curly brace on a line of its own, indented at the same level as the previous line.
-nooptions		All
	Does not display any options at all.
-basic		All
	Displays the basic options for the hsa program.
-advanced		All
	Displays all the available options for the hsa program.

hsa Applications

• Submit
• PrintFiles
• PrettyPrint

Submit

Introduction

This brings up dialog boxes to allow the user to enter the name of the program to be submitted, the names of the Java text files that make up the program, and the namesof the test data files. It then prints the Java text files, the input files, and the output produced from running the program.

Instructions

Figure 1 The Submit Dialog Box

The Select Source Files dialog box (See Select Source Files dialog box) contains two lists of files, the files found on the disk and the list of Java text files to be printed. The dialog box only lists directories and those files that end in ".java" (which should be the case for all Java text files). To select files to be printed, you can either double click on the file name, or click once on the file name and then click the Copy > button. To move to a different directory, click on the directory name (all directory names are enclosed in square brackets). The name of the current directory is listed above the file name list on the left side. To switch to a different drive, select the drive from the pop-up menu beneath the list of files in the current directory.

Figure 2 The Select Source Files Dialog Box

If you accidently select a Java text file to be printed that should not be included, double clicking on the filename in the right hand list of files will remove it. Once all the Java text files that the program uses have been entered, click the Next > button. The list of Java text files to be printed appears in a window labelled Source Files in the upper-left corner of the screen. The Select Input Files dialog box appears in the center of the screen (See Select Input Files dialog box).

Figure 3 The Select Input Files Dialog Box

This dialog box allows you to select files that will be used as input to the submitted program when it runs. The submitted program will be run once for each input file selected. For each run, instead of reading from standard input (or the hsa Console class), the submitted program will read from the input file. If no input files are selected, the submitted program will be run once using no input. Any text file can be used as an input file. Once all the files are selected, click the Finish button.

At this point, the Submit program will close the Select Input Files dialog box, display a small dialog box called Test Input Files in the upper-right corner of the screen listing the selected input files and start printing. The printout contains a copy of all the Java text files selected, and then for each input file, the input file and the output from the submitted program using that input file. When it is finished printing, the Submit program quits. The printout can be submitted for marking by your instructor.

PrintFiles

Introduction

Instructions

The PrintFiles Options dialog box appears (see PrintFiles Options dialog box). You can change any options at this point as described in the Setting Options section. Once the appropriate options are set (usually you will not need to change any of them from the default setting), click the OK button in the dialog box. The PrintFiles Options dialog box closes and the Select Files To Print dialog box appears.

Figure 4 The PrintFiles Options Dialog Box

The Select Files To Print dialog box (see Select Files To Print dialog box) contains two lists of files, the files found on the disk and the list of Java text files to be printed. The dialog box only lists directories and those files that end in ".java" (which all Java text files should end in). To select files to be printed, you can either double click on the file name, or click once on the file name and then click the Copy > button. To move to a different directory, click on the directory name (all directory names are enclosed in square brackets). The name of the current directory is listed above the file name list on the left side. To switch to a different drive, select the drive from the pop-up menu beneath the list of files in the current directory.

Figure 5 The Select Files to Print Dialog Box

If you accidently select a Java text file to be printed that should not be included, double clicking on the filename in the right hand list of files will remove it. Once all the Java text files that the program uses have been entered, click the Finish button. The selected files are now printed.

PrettyPrint

Introduction

Because VisualAge for Java has its own system for handling tabs, there are paragraphing problems when importing and exporting Java files to and from other environments. PrettyPrint paragraphs (indents) Java files to make them suitable for printing or use in other environments, or suitable for importation into VisualAge for Java. This program makes it easier to transport Java files between the VisualAge for Java and other Java environments.

Instructions

Figure 6 The PrettyPrint Options Dialog Box

The Select Files To Indent dialog box (see Select Files To Indent dialog box) contains two lists of files, the files found on the disk and the list of Java text files to be printed. The dialog box only lists directories and those files that end in ".java" (which all Java text files should end in). To select files to be printed, you can either double click on the file name, or click once on the file name and then click the Copy > button. To move to a different directory, click on the directory name (all directory names are enclosed in square brackets). The name of the current directory is listed above the file name list on the left side. To switch to a different drive, select the drive from the pop-up menu beneath the list of files in the current directory.

Figure 7 The Select Files to Indent Dialog Box

If you accidently select a Java text file to be printed that should not be included, double clicking on the filename in the right hand list of files will remove it. Once all the Java text files that the program uses have been entered, click the Finish button. The selected files are then indented and saved with the same name as before. You can now copy the Java text files to a different environment.

hsa Classes

• Console
  • Introduction
  • Constructors and General Methods
  • Graphics Methods
  • Text Input and Output Methods
  • Example Program
• TextConsole
  • Introduction
  • Constructors and General Methods
  • Text Input and Output Methods
  • Example Program
• Stdin
  • Introduction
  • Methods
  • Example Program
• Stdout
  • Introduction
  • Methods
  • Example Program
• TextInputFile
  • Introduction
  • Constructors and Methods
  • Example Program
• TextOutputFile
  • Introduction
  • Constructors and Methods
  • Example Program
• FatalError
  • Introduction
  • Constructors and Methods
  • Example Program
• Message
  • Introduction
  • Constructors and Methods
  • Example Program
• Status
  • Introduction
  • Constructors and Methods
  • Example Program

Console

• Introduction
• Constructors and General Methods
• Graphics Methods
• Text Input and Output Methods
• Example Program

Introduction

The Console class window has three buttons. The Save button saves the contents of the screen as a ".bmp" (Windows Bitmap) file. The Print button prints out the contents of the window. The Quit button quits the program immediately. It gives visual notification when the program is finished execution by changing the label in the Quit button to Close.

General Methods and Constructors

Console ()

Constructor - Creates a Console window of 25 rows by 80 columns.

Console (int fontSize)

Constructor - Creates a Console window with the text size set to fontSize.

Console (int rows, int cols)

Constructor - Creates a Console window with width of cols columns and height of rows rows.

Console (int rows, int cols, int fontSize)

Constructor - Creates a Console window with width of cols columns, height of rows rows, and the text size set to fontSize.

Console (String title)

Constructor - Creates a Console window and sets the window title to title.

Console (int fontSize, String title)

Constructor - Creates a Console window with the text size set to fontSize and sets the window title to title.

Console (int rows, int cols, String title)

Constructor - Creates a Console window with width of cols columns, height of rows rows, and the window title set to title.

Console (int rows, int cols, int fontSize, String title)

Constructor - Creates a Console window with width of cols columns, height of rows rows, the text size set to fontSize, and the window title set to title.

void close ()

Closes the Console window and disposes of its contents.

Graphics Methods

void clearRect (int x, int y, int width, int height)

Clears the rectangle to the background color.

void copyArea (int x, int y, int width, int height, int deltaX, int deltaY)

Copies the rectangle defined by the upper-left corner (x, y) with width of width and height of height to a position moved by deltaX and deltaY pixels.

void draw3DRect (int x, int y, int width, int height, boolean raised)

Draws a 3-D rectangle. It appears raised if raised is true.

void drawArc (int x, int y, int width, int height, int startAngle, int arcAngle)

Draws an arc. The arc is inscribed in the rectangle defined by the upper- left corner (x, y) with width of width and height of height. It starts at startAngle degrees and goes counterclockwise for arcAngle degrees.

void drawLine (int x1, int y1, int x2, int y2)

Draws a line from (x1, y1) to (x2, y2).

void drawMapleLeaf (int x, int y, int width, int height)

Draws a maple leaf. The maple leaf is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

void drawOval (int x, int y, int width, int height)

Draws an ellipse. The ellipse is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

void drawPolygon (int[] xPoints, int[] yPoints, int numPoints)

Draws a polygon. The xPoints and yPoints arrays define the coordinates of the array of vertices. numPoints specifies the number of vertices in the polygon.

void drawRect (int x, int y, int width, int height)

Draws a rectangle with upper-left corner at (x, y) with width of width and height of height.

void drawRoundRect (int x, int y, int width, int height, int arcWidth, int arcHeight)

Draws a rectangle with rounded corners with upper-left corner at (x, y) with width of width and height of height. arcWidth and arcHeight are the width and height of the ellipse used to draw the rounded corners.

void drawStar (int x, int y, int width, int height)

Draws a star. The star is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

void drawString (String str, int x, int y)

Draws the string str at the starting point (x, y). The y coordinate is the base line of the text.

void fill3DRect (int x, int y, int width, int height, boolean raised)

Draws a filled 3-D rectangle. It appears raised if raised is true.

void fillArc (int x, int y, int width, int height, int startAngle, int arcAngle)

Draws a filled arc. The arc is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height. It starts at startAngle degrees and goes counterclockwise for arcAngle degrees.

void fillMapleLeaf (int x, int y, int width, int height)

Draws a filled maple leaf. The maple leaf is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

void fillOval (int x, int y, int width, int height)

Draws a filled ellipse. The ellipse is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

void fillPolygon (int[] xPoints, int[] yPoints, int numPoints)

Draws a filled polygon. The xPoints and yPoints arrays define the coordinates of the array of vertices. numPoints specifies the number of vertices in the polygon.

void fillRect (int x, int y, int width, int height)

Draws a filled rectangle with upper-left corner at (x, y) with width of width and height of height.

void fillRoundRect (int x, int y, int width, int height, int arcWidth, int arcHeight)

Draws a filled rectangle with rounded corners with upper-left corner at (x, y) with width of width and height of height. arcWidth and arcHeight are the width and height of the ellipse used to draw the rounded corners.

void fillStar (int x, int y, int width, int height)

Draws a filled star. The star is inscribed in the rectangle defined by the upper-left corner (x, y) with width of width and height of height.

int getWidth ()

Returns the width of the Console window in pixels.

int getHeight ()

Returns the height of the Console window in pixels.

void setColor (Color c)

Sets the color of the graphics context. The color is used for any draw methods.

void setFont (Font f)

Sets the font of the graphics context. The font is used with the drawString method.

void setPaintMode ()

Sets the graphics context into paint mode. All drawing in the graphics context draws over the background.

void setXORMode (Color c)

Sets the graphics context into XOR mode. All drawing in the graphics context is XOR'd with the background. The color specified by c is a special color so that any drawing done on a background of color c will not be changed.

Text Input and Output Methods

void clear ()

Clears the entire Console window and sets the cursor to the upper-left corner.

int getMaxColumns ()

Returns the width of the Console window in columns.

int getMaxRows ()

Returns the height of the Console window in rows.

int getColumn ()

Returns the column number of the current cursor position.

int getRow ()

Returns the row number of the current cursor position.

void print (byte b)
void print (short s)
void print (int i)
void print (long l)
void print (float f)
void print (double d)
void print (boolean b)
void print (char c)
void print (String s)

Outputs the argument to the Console window beginning at the cursor position.

void print (byte number, int fieldSize)
void print (short number, int fieldSize)
void print (int number, int fieldSize)
void print (long number, int fieldSize)

Outputs number to the Console window in a field of width fieldSize beginning at the cursor position. If the number (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (float number, int fieldSize)
void print (double number, int fieldSize)

Outputs number to the Console window in a field of width fieldSize beginning at the cursor position. The method adjusts the number of decimal places displayed to fit in the field, if possible. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (boolean b, int fieldSize)
void print (char c, int fieldSize)
void print (String s, int fieldSize)

Outputs the argument to the Console window in a field of width fieldSize beginning at the cursor position. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is left justified.

void print (double number, int fieldSize, int decimalPlaces)
void print (float number, int fieldSize, int decimalPlaces)

Outputs number to the Console window in a field of width fieldSize with decimalPlaces number of decimal places beginning at the cursor position. The field width is ignored if the number will not fit. The output is right justified.

void println ()

Outputs a Return at the cursor position to the Console window.

void println (byte b)
void println (short s)
void println (int i)
void println (long l)
void println (float f)
void println (double d)
void println (boolean b)
void println (char c)
void println (String s)
void println (byte b, int fieldSize)
void println (short s, int fieldSize)
void println (int i, int fieldSize)
void println (long l, int fieldSize)
void println (float f, int fieldSize)
void println (double d, int fieldSize)
void println (boolean b, int fieldSize)
void println (char c, int fieldSize)
void println (String s, int fieldSize)
void println (float f, int fieldSize, int decimalPlaces)
void println (double d, int fieldSize, int decimalPlaces)

Identical to print method with same arguments, except that a Return is output after the argument.

byte readByte ()

Returns the byte value (-128 to 127) read from the keyboard.

short readShort ()

Returns the 2-byte integer (-32,768 to 32,767) read from the keyboard.

int readInt ()

Returns the 4-byte integer (-2,147,483,648 to 2,147,483,647) read from the keyboard.

long readLong ()

Returns the 8-byte integer read from the keyboard.

float readFloat ()

Returns the 4-byte float read from the keyboard.

double readDouble ()

Returns the 8-byte double read from the keyboard.

boolean readBoolean ()

Returns the boolean value (either true or false, case insensitive) read from the keyboard.

char readChar ()

Returns the character read from the keyboard.

String readString ()

Returns the String read from the keyboard.

String readLine ()

Returns the entire line of input read from the keyboard without the Return.

void setTextColor (Color c)

Sets the color for text output from print and println methods.

void setTextBackgroundColor (Color c)

Sets the background color for text output from print and println methods.

void showCursor ()

Shows the text cursor, if invisible.

void hideCursor ()

Hides the text cursor, if visible.

void setCursor (int row, int col)

Sets the cursor position to row row and column col.

Example

      import java.awt.*;
      import hsa.Console;

      public class TestConsole
      {
          public static void main (String[] args)
          {
              Console c = new Console ();
              c.print ("Enter the radius of the circle: ");
              int radius = c.readInt ();
              c.setColor (Color.green);
              c.fillOval (c.getWidth () / 2 - radius, c.getHeight () / 2 - radius,
                  radius * 2, radius * 2);
          } // main method
      } /* TestConsole class */
  

TextConsole

• Introduction
• Constructors and General Methods
• Text Input and Output Methods
• Example Program

Introduction

The user can input data directly into the Console window. The output of the program also appears there. Formatted text output is provided.

The TextConsole class window has three buttons. The Save button saves all output sent to the window to a text file. The Print button prints out all of the output. The Quit button quits the program immediately. It gives visual notification when the program is finished execution by changing the label in the Quit button to Close.

General Methods and Constructors

TextConsole ()

Constructor - Creates a TextConsole window of 25 rows by 80 columns.

TextConsole (int fontSize)

Constructor - Creates a TextConsole window with the text size set to fontSize.

TextConsole (int rows, int cols)

Constructor - Creates a TextConsole window with width of cols columns and height of rows rows.

TextConsole (int rows, int cols, int fontSize)

Constructor - Creates a TextConsole window with width of cols columns, height of rows rows, and the text size set to fontSize.

TextConsole (String title)

Constructor - Creates a TextConsole window and sets the window title to title.

TextConsole (int fontSize, String title)

Constructor - Creates a TextConsole window with the text size set to fontSize and sets the window title to title.

TextConsole (int rows, int cols, String title)

Constructor - Creates a TextConsole window with width of cols columns, height of rows rows, and the window title set to title.

TextConsole (int rows, int cols, int fontSize, String title)

Constructor - Creates a TextConsole window with width of cols columns, height of rows rows, the text size set to fontSize, and the window title set to title.

void close ()

Closes the TextConsole window and disposes of its contents.

Text Input and Output Methods

void print (byte b)
void print (short s)
void print (int i)
void print (long l)
void print (float f)
void print (double d)
void print (boolean b)
void print (char c)
void print (String s)

Outputs the argument to the Console window beginning at the cursor position.

void print (byte number, int fieldSize)
void print (short number, int fieldSize)
void print (int number, int fieldSize)
void print (long number, int fieldSize)

Outputs number to the Console window in a field of width fieldSize beginning at the cursor position. If the number (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (float number, int fieldSize)
void print (double number, int fieldSize)

Outputs number to the Console window in a field of width fieldSize beginning at the cursor position. The method adjusts the number of decimal places displayed to fit in the field, if possible. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (boolean b, int fieldSize)
void print (char c, int fieldSize)
void print (String s, int fieldSize)

Outputs the argument to the Console window in a field of width fieldSize beginning at the cursor position. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is left justified.

void print (double number, int fieldSize, int decimalPlaces)
void print (float number, int fieldSize, int decimalPlaces)

Outputs number to the Console window in a field of width fieldSize with decimalPlaces number of decimal places beginning at the cursor position. The field width is ignored if the number will not fit. The output is right justified.

void println ()

Outputs a Return at the cursor position to the Console window.

void println (byte b)
void println (short s)
void println (int i)
void println (long l)
void println (float f)
void println (double d)
void println (boolean b)
void println (char c)
void println (String s)
void println (byte b, int fieldSize)
void println (short s, int fieldSize)
void println (int i, int fieldSize)
void println (long l, int fieldSize)
void println (float f, int fieldSize)
void println (double d, int fieldSize)
void println (boolean b, int fieldSize)
void println (char c, int fieldSize)
void println (String s, int fieldSize)
void println (float f, int fieldSize, int decimalPlaces)
void println (double d, int fieldSize, int decimalPlaces)

Identical to print method with same arguments, except that a Return is output after the argument.

byte readByte ()

Returns the byte value (-128 to 127) read from the keyboard.

short readShort ()

Returns the 2-byte integer (-32,768 to 32,767) read from the keyboard.

int readInt ()

Returns the 4-byte integer (-2,147,483,648 to 2,147,483,647) read from the keyboard.

long readLong ()

Returns the 8-byte integer read from the keyboard.

float readFloat ()

Returns the 4-byte float read from the keyboard.

double readDouble ()

Returns the 8-byte double read from the keyboard.

boolean readBoolean ()

Returns the boolean value (either true or false, case insensitive) read from the keyboard.

char readChar ()

Returns the character read from the keyboard.

String readString ()

Returns the String read from the keyboard.

String readLine ()

Returns the entire line of input read from the keyboard without the Return.

Example

      import java.awt.*;
      import hsa.TextConsole;

      public class TestTextConsole
      {
          public static void main (String[] args)
          {
              TextConsole c = new TextConsole ();
              c.print ("Enter the times table: ");
              int multiplier = c.readInt ();
              for (int count = 1 ; count <= 50 ; count++)
              {
                  c.print (count, 3);
                  c.print (count * multiplier, 4);
              }
          } // main method
      } /* TestTextConsole class */
  

Stdin

• Introduction
• Methods
• Example Program

Introduction

Methods

static void close ()

Closes standard input to prevent further reading.

static boolean eof ()

Returns true if the next thing to be read from the keyboard is the end-of-file marker. (You can generate an end-of-file by pressing either Ctrl+Z or Ctrl+D.)

static byte readByte ()

Returns the byte value (-128 to 127) read from the keyboard.

static short readShort ()

Returns the 2-byte integer (-32,768 to 32,767) read from the keyboard.

static int readInt ()

Returns the 4-byte integer (-2,147,483,648 to 2,147,483,647) read from the keyboard.

static long readLong ()

Returns the 8-byte integer read from the keyboard.

static float readFloat ()

Returns the 4-byte float read from the keyboard.

static double readDouble ()

Returns the 8-byte double read from the keyboard.

static boolean readBoolean ()

Returns the boolean value (either true or false, case insensitive) read from the keyboard.

static char readChar ()

Returns the character read from the keyboard.

static String readString ()

Returns the String read from the keyboard.

static String readLine ()

Returns the entire line of input read from the keyboard without the Return.

Example

Stdout

• Introduction
• Methods
• Example Program

Introduction

Methods

static void print (byte b)
static void print (short s)
static void print (int i)
static void print (long l)
static void print (float f)
static void print (double d)
static void print (boolean b)
static void print (char c)
static void print (String s)

Outputs the argument to standard output.

static void print (byte number, int fieldSize)
static void print (short number, int fieldSize)
static void print (int number, int fieldSize)
static void print (long number, int fieldSize)

Outputs number to standard output in a field of width fieldSize. If the number (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

static void print (float number, int fieldSize)
static void print (double number, int fieldSize)

Outputs number to standard output in a field of width fieldSize. The method adjusts the number of decimal places displayed to fit in the field, if possible. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

static void print (boolean b, int fieldSize)
static void print (char c, int fieldSize)
static void print (String s, int fieldSize)

Outputs the argument to standard output in a field of width fieldSize. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is left justified.

static void print (double number, int fieldSize, int decimalPlaces)
static void print (float number, int fieldSize, int decimalPlaces)

Outputs number to standard output in a field of width fieldSize with decimalPlaces number of decimal places. The field width is ignored if the number will not fit. The output is right justified.

static void println ()

Output a Return to standard output.

static void println (byte b)
static void println (short s)
static void println (int i)
static void println (long l)
static void println (float f)
static void println (double d)
static void println (boolean b)
static void println (char c)
static void println (String s)
static void println (byte b, int fieldSize)
static void println (short s, int fieldSize)
static void println (int i, int fieldSize)
static void println (long l, int fieldSize)
static void println (float f, int fieldSize)
static void println (double d, int fieldSize)
static void println (boolean b, int fieldSize)
static void println (char c, int fieldSize)
static void println (String s, int fieldSize)
static void println (float f, int fieldSize, int decimalPlaces)
static void println (double d, int fieldSize, int decimalPlaces)

Identical to print method with same arguments, except that a Return is output after the argument.

Example

      import hsa.*;

      // Reads and writes number to standard input and output.
      public class TestStdinStdout
      {
          public static void main (String[] args)
          {
              Stdout.println ("Calculate square roots");
              while (true)
              {
                  Stdout.print ("Enter a number: ");
                  if (Stdin.eof ()) break;
                  double number = Stdin.readDouble ();
                  if (number < 0)
                  {
                      // Instantiating a FatalError object displays an
                      // error window and then quits the program.
                      new FatalError ("Attempted to take the square " +
                                      "root of a negative number");
                      // Never reaches here.
                  }
                  Stdout.print ("The square root of ");
                  Stdout.print (number)
                  Stdout.print (" is ");
                  Stdout.println (Math.sqrt (number), 8, 5);
              }
          } // main method
      } /* TestStdinStdout class */
  

TextInputFile

• Introduction
• Constructors and Methods
• Example Program

Introduction

Constructors and Methods

TextInputFile ()

Constructor - Opens standard input as a TextInputFile.

TextInputFile (File file)

Constructor - Opens file as a TextInputFile.

TextInputFile (String fileName)

Constructor - Opens file with name fileName as a TextInputFile. If fileName is "Standard Input", "Keyboard" or "Stdin" (case irrelevant), standard input is opened as a TextInputFile.

void close ()

Closes the TextInputFile to prevent further reading.

boolean eof ()

Returns true if the next thing to be read from the file is the end-of-file marker. (When reading from standard input, you can generate an end-of- file by pressing either Ctrl+Z or Ctrl+D.)

byte readByte ()

Returns the byte value (-128 to 127) read from the file.

short readShort ()

Returns the 2-byte integer (-32,768 to 32,767) read from the file.

int readInt ()

Returns the 4-byte integer (-2,147,483,648 to 2,147,483,647) read from the file.

long readLong ()

Returns the 8-byte integer read from the file.

float readFloat ()

Returns the 4-byte float read from the file.

double readDouble ()

Returns the 8-byte double read from the file.

boolean readBoolean ()

Returns the boolean value (either true or false, case insensitive) read from the file.

char readChar ()

Returns the character read from the file.

String readString ()

Returns the String read from the file.

String readLine ()

Returns the entire line of input read from the file without the Return.

Example

      import hsa.*;

      // Reads a file of integers and calculate their square roots
      public class TestTextInputFile
      {
          public static void main (String[] args)
          {
              String fileName;
              TextInputFile f;
              int lineNumber = 1;
              Stdout.print ("Enter the file to be read: ");
              fileName = Stdin.readLine ();
              f = new TextInputFile (fileName);
              while (!f.eof ())
              {
                  double number = f.readDouble ();
                  Stdout.print (number, 10, 4);
                  Stdout.print (" ");
                  Stdout.println (Math.sqrt (number), 10, 4);
              }
              f.close ();
          } // main method
      } /* TestTextInputFile class */
  

TextOutputFile

• Introduction
• Constructors and Methods
• Example Program

Introduction

Constructors and Methods

TextOutputFile ()

Constructor - Opens standard output as a TextOutputFile.

TextOutputFile (File file)

Constructor - Opens file as a TextOutputFile.

TextOutputFile (String fileName)

Constructor - Opens file with name fileName as a TextOutputFile. If fileName is "Standard Output", "Screen" or "Stdout" (case irrelevant), standard output is opened as a TextOutputFile.

TextOutputFile (File file, boolean append)

Constructor - Opens file as a TextOutputFile. If append is true, any output will be appended to the file.

TextOutputFile (String fileName, boolean append)

Constructor - Opens file with name fileName as a TextOutputFile. If append is true, any output will be appended to the file. If fileName is "Standard Output", "Screen" or "Stdout" (case irrelevant), standard output is opened as a TextOutputFile.

void close ()

Closes the TextOutputFile to prevent further writing.

void print (byte b)
void print (short s)
void print (int i)
void print (long l)
void print (float f)
void print (double d)
void print (boolean b)
void print (char c)
void print (String s)

Outputs the argument to the file.

void print (byte number, int fieldSize)
void print (short number, int fieldSize)
void print (int number, int fieldSize)
void print (long number, int fieldSize)

Outputs number to the file in a field of width fieldSize. If the number (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (float number, int fieldSize)
void print (double number, int fieldSize)

Outputs number to the file in a field of width fieldSize. The method adjusts the number of decimal places displayed to fit in the field, if possible. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is right justified within the field.

void print (boolean b, int fieldSize)
void print (char c, int fieldSize)
void print (String s, int fieldSize)

Outputs the argument to the file in a field of width fieldSize. If the argument (when converted to String) is larger than fieldSize, fieldSize is ignored. The output is left justified.

void print (double number, int fieldSize, int decimalPlaces)
void print (float number, int fieldSize, int decimalPlaces)

Outputs number to the file in a field of width fieldSize with decimalPlaces number of decimal places. The field width is ignored if the number will not fit. The output is right justified.

void println ()

Output a Return to the file.

void println (byte b)
void println (short s)
void println (int i)
void println (long l)
void println (float f)
void println (double d)
void println (boolean b)
void println (char c)
void println (String s)
void println (byte b, int fieldSize)
void println (short s, int fieldSize)
void println (int i, int fieldSize)
void println (long l, int fieldSize)
void println (float f, int fieldSize)
void println (double d, int fieldSize)
void println (boolean b, int fieldSize)
void println (char c, int fieldSize)
void println (String s, int fieldSize)
void println (float f, int fieldSize, int decimalPlaces)
void println (double d, int fieldSize, int decimalPlaces)

Identical to print method with same arguments, except that a Return is output after the argument.

Example

      import hsa.*;

      // Saves a Times table to a file.
      public class TestTextOutputFile
      {
          public static void main (String[] args)
          {
              String fileName;
              TextOutputFile f;
              int lineNumber = 1;
              Stdout.print ("Enter the file to be written: ");
              fileName = Stdin.readLine ();
              f = new TextOutputFile (fileName);
              f.print (" ", 6);               // Print 6 spaces
              for (int i = 1 ; i <= 12 ; i++) // Print numbers across top
              {
                  f.print (i, 4);
              }
              for (int i = 1 ; i <= 12 ; i++)
              {
                  f.print (i, 4);
                  f.print ("  ");
                  for (int j = 1 ; j <= 12 ; j++)
                  {
                      f.print (i * j, 4);
                  }
                  f.println ();
              }
              f.close ();
          } // main method
      } /* TestTextOutputFile class */
  

FatalError

• Introduction
• Constructors and Methods
• Example Program

Introduction

Constructors and Methods

FatalError (String message)

Constructor - Displays message in a window titled Fatal Error centered on the screen. When the Quit button is pressed, the program exits immediately.

FatalError (String message, Frame frame)

Constructor - Displays message in a window titled Fatal Error centered on the Frame frame. When the Quit button is pressed, the program exits immediately.

Example

Message

• Introduction
• Constructors and Methods
• Example Program

Introduction

Constructors and Methods

Message (String message)

Constructor - Displays message in a untitled window centered on the screen. When the OK button is pressed, execution returns from the call to the constructor.

Message (String message, String title)

Constructor - Displays message in a window titled title centered on the screen. When the OK button is pressed, execution returns from the call to the constructor.

Message (String message, Frame frame)

Constructor - Displays message in a untitled window centered on Frame frame. When the OK button is pressed, execution returns from the call to the constructor.

Message (String message, String title, Frame frame)

Constructor - Displays message in a window titled title centered on Frame frame. When the OK button is pressed, execution returns from the call to the constructor.

static void beep ()

Causes the computer to beep. Useful for catching the user's attention.

Example

      import hsa.*;

      // Display four messages, one after another.
      public class TestMessage
      {
          public static void main (String[] args)
          {
              new Message ("This is the first message", "First message");
              new Message ("This is the second message", "Second message");
              new Message ("This is the third message", "Third message");
              new Message ("This is the last message", "Last message");
          } // main method
      } /* TestMessage class */
  

Status

• Introduction
• Constructors and Methods
• Example Program

Introduction

Constructors and Methods

Status (String message)

Constructor - Displays message in a untitled window centered on the screen. The window only disappears when the hide () method is called or the user clicks the window's Close button (the X on the right hand side of the window's title bar). Execution returns from the call to the constructor immediately.

Status (String message, String title)

Constructor - Displays message in a window titled title centered on the screen. The window only disappears when the hide () method is called or the user clicks the window's Close button (the X on the right hand side of the window's title bar). Execution returns from the call to the constructor immediately.

Status (String message, Frame frame)

Constructor - Displays message in a untitled window centered on Frame frame. The window only disappears when the hide () method is called or the user clicks the window's Close button (the X on the right hand side of the window's title bar). Execution returns from the call to the constructor immediately.

Status (String message, String title, Frame frame)

Constructor - Displays message in a window titled title centered on Frame frame. The window only disappears when the hide () method is called or the user clicks the window's Close button (the X on the right hand side of the window's title bar). Execution returns from the call to the constructor immediately.

void setMessage (String message)

Changes the message in the window to message.

void hide ()

Hides the window.

void show ()

Shows the window.

void dispose ()

Hides the window and disposes of its contents.

Example

      import hsa.*;

      // Count number of lines in a file
      public class TestStatus
      {
          public static void main (String[] args)
          {
              String fileName;
              TextInputFile f;
              Status status;
              int lineNumber = 1;
              Stdout.print ("Enter the file to have lines counted: ");
              fileName = Stdin.readLine ();
              f = new TextInputFile (fileName);

              // Open status window.
              status = new Status ("Reading " + fileName);

              while (!f.eof ())
              {
                  f.readLine ();

                  // Change status message.
                  status.setMessage ("Reading line number " + lineNumber);

                  lineNumber++;
              }

              // Close status window.
              status.dispose ();

              f.close (); // Close the text file.

              Stdout.println ("There were " + lineNumber +
                              " lines in " + fileName);
        } // main method
    } /* TestStatus class */