package java.lancs;/** * simple methods for file input/output (Java 1.1) * @author Roger Garside * @version Last Rewritten: 16/Sept/97 */import java.io.* ;public class BasicFileIo                                   {    /**     * Constant - input file     */    public static final int INPUT = 1 ;                              /**     * Constant - output file     */    public static final int OUTPUT = 2 ;    private int fileType ;    private PrintWriter pout ;    private BufferedReader fin ;    /**     * Constructor for BasicFileIo.     * Initialises the filetype to "unknown".     */    public BasicFileIo()         {        fileType = 0 ;        } // end of constructor method    /**     * Constructor for BasicFileIo.     * @param t    The filetype - either INPUT or OUPUT     * @param name The filename as a string     * @throws IOException If there is a problem opening the file     */    public BasicFileIo(int t, String name) throws IOException        {        if (t == OUTPUT)            {            pout = new PrintWriter(new FileWriter(name)) ;            fileType = OUTPUT ;            }        else if (t == INPUT)            {            fin = new BufferedReader(new FileReader(name)) ;            fileType = INPUT ;            }        else	    {            System.exit(1) ;            }        } // end of constructor method    /**     * Open a file. Can be opened for reading or writing     * @param t    The filetype - either INPUT or OUPUT     * @param name The filename as a string     * @throws IOException If there is a problem opening the file     */    public void openFile(int t, String name) throws IOException        {        if (fileType != 0)            {            System.exit(1) ;            }        if (t == OUTPUT)            {            pout = new PrintWriter(new FileWriter(name)) ;            fileType = OUTPUT ;            }        else if (t == INPUT)            {            fin = new BufferedReader(new FileReader(name)) ;            fileType = INPUT ;            }        else            {            System.exit(1) ;            }        } // end of method openFile    /**     * Close the current file     */    public void closeFile() throws IOException        {        if (fileType == INPUT) 	    fin.close() ;        else if (fileType == OUTPUT)	    pout.close() ;        else            System.exit(1) ;        fileType = 0 ;        } // end of method close    public void print(boolean b)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(b) ;        } // end of method print    public void print(char c)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(c) ;        } // end of method print    public void print(double d)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(d) ;        } // end of method print    public void print(float f)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(f) ;        } // end of method print    public void print(int i)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(i) ;        } // end of method print    public void print(long l)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(l) ;        } // end of method print    public void print(String s)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.print(s) ;        } // end of method print    public void println(boolean b)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(b) ;        } // end of method println    public void println(char c)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(c) ;        } // end of method println    public void println(double d)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(d) ;        } // end of method println    public void println(float f)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(f) ;        } // end of method println    public void println(int i)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(i) ;        } // end of method println    public void println(long l)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(l) ;        } // end of method println    public void println(String s)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println(s) ;        } // end of method println    public void println()        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        pout.println() ;        } // end of method println    /**     * read the next line from the file as a String     * @return the line read from the file as a String     * @throws IOException if an error occurs while reading the file     */    public String readString() throws IOException        {        if (fileType != INPUT)            {            System.err.println("not open for reading") ;            System.exit(1) ;            }        return fin.readLine() ;        } // end of method readString    /**     * Read a character from the file, the first on the line     * @return the first character on the next line     * @throws IOException If an error occurs while reading the file     */    public char readCharacter() throws IOException        {        if (fileType != INPUT)            {            System.err.println("not open for reading") ;            System.exit(1) ;            }        String line = fin.readLine() ;        if (line.length() == 0)            return ' ' ;        else            return line.charAt(0) ;        } // end of method readCharacter       /**     * read the next line from the file as an integer     * @return the line read from the file as an integer     * @throws IOException If the value read is not a valid integer     */    public int readInteger() throws IOException        {        String line ;        if (fileType != INPUT)            {            System.err.println("not open for reading") ;            System.exit(1) ;            }        try {            line = fin.readLine() ;            int i = Integer.parseInt(line.trim()) ;            return i ;            }        catch (Exception e)            {            throw new IOException("invalid integer") ;            }        } // end of method readInteger    /**     * read a float value from the file     * @return the float value read from the file     * @throws IOException If value read is not a valid float value     */    public float readFloat() throws IOException        {        String line ;        if (fileType != INPUT)            {            System.err.println("not open for reading") ;            System.exit(1) ;            }        try {            line = fin.readLine() ;            float f = Float.valueOf(line.trim()).floatValue() ;            return f ;            }        catch (Exception e)            {            throw new IOException("invalid float") ;            }        } // end of method readFloat      /**     * read a double value from the file     * @return the double value read from the file     * @throws IOException If value read is not a valid double value     */    public double readDouble() throws IOException        {        String line ;        if (fileType != INPUT)            {            System.err.println("not open for reading") ;            System.exit(1) ;            }        try {            line = fin.readLine() ;            double d = Double.valueOf(line.trim()).doubleValue() ;            return d ;            }        catch (Exception e)            {            throw new IOException("invalid double") ;            }        } // end of method readDouble    /**     * Write an integer to the file     * @param n The integer to be written     * @param w The width of the field to write the integer in     */    public void writeInteger(int n, int w)        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing") ;            System.exit(1) ;            }        Integer n1 = new Integer(n) ;        String t = n1.toString() ;        if (t.length() > w)            pout.print(t) ;        else            {            for (int i = 0 ; i < w - t.length() ; i++)                pout.print(' ') ;            pout.print(t) ;            }        } // end of method writeInteger    /**     * output a float to the file in a field of a specified width     * @param n the float to be output to the file     * @param w the width of the field     * @param d the number of decimal places     */    public void writeFloat(float n, int w, int d) throws IOException        {        if (fileType != OUTPUT)            {            System.err.println("not open for writing");            System.exit(1);            }              Float f1 = new Float(n);        String t = f1.toString();      	if (t.indexOf('e') != -1)	    throw new IOException("out of range") ;        if (d < 1)	    throw new IOException("invalid 3rd argument") ;	boolean negative = false ;	if (t.charAt(0) == '-')	    {	    negative = true ;	    t = t.substring(1) ;	    }	int index = t.indexOf('.') ;	int decimals ;	if (index == -1)	    decimals = 0 ;	else	    {	    decimals = t.length() - index - 1 ;            if (decimals <= 0)		throw new IOException("funny format") ;	    }	if (decimals < d)	    {	    if (decimals == 0)		t += '.' ;	    for (int i = 0 ; i < d - decimals ; i++)		t += '0' ;	    }	else if (decimals > d)	    {	    int offset = t.length() - decimals + d ;	    if (t.charAt(offset) < '5')		t = t.substring(0, t.length() - decimals + d) ;	    else		{		StringBuffer sb = new StringBuffer(t) ;		offset-- ;		while ((offset >= 0) &&		       ((sb.charAt(offset) == '9') ||		        (sb.charAt(offset) == '.')))		    {		    if (sb.charAt(offset) == '9')		        sb.setCharAt(offset, '0') ;		    offset-- ;		    }		if (offset >= 0)		    {		    sb.setCharAt(offset,	Character.forDigit(Character.digit(sb.charAt(offset), 10) + 1, 10)) ;	t = sb.toString().substring(0, t.length() - decimals + d) ;		    }		else	t = '1' + sb.toString().substring(0, t.length() - decimals + d) ;		}	    }	if (negative)	    t = '-' + t ;	if (t.length() > w)	    pout.print(t) ;	else	    {	    for (int i = 0 ; i < w - t.length() ; i++)		pout.print(' ') ;	    pout.print(t) ;	    }        } // end of method writeFloat    /**     * output a double to the file in a field of a specified width     * @param n the double to be output to the file     * @param w the width of the field     * @param d the number of decimal places     */    public void writeDouble(double n, int w, int d) throws IOException	{        if (fileType != OUTPUT)            {            System.err.println("not open for writing");            System.exit(1);            }      	Double n1 = new Double(n) ;	String t = n1.toString() ;	//System.err.println("string is **" + t + "**") ;	if (t.indexOf('e') != -1)	    throw new IOException("out of range") ;        if (d < 1)	    throw new IOException("invalid 3rd argument") ;	boolean negative = false ;	if (t.charAt(0) == '-')	    {	    negative = true ;	    t = t.substring(1) ;	    }	int index = t.indexOf('.') ;	int decimals ;	if (index == -1)	    decimals = 0 ;	else	    {	    decimals = t.length() - index - 1 ;            if (decimals <= 0)		throw new IOException("funny format") ;	    }	if (decimals < d)	    {	    if (decimals == 0)		t += '.' ;	    for (int i = 0 ; i < d - decimals ; i++)		t += '0' ;	    }	else if (decimals > d)	    {	    int offset = t.length() - decimals + d ;	    if (t.charAt(offset) < '5')		t = t.substring(0, t.length() - decimals + d) ;	    else		{		StringBuffer sb = new StringBuffer(t) ;		offset-- ;		while ((offset >= 0) &&		       ((sb.charAt(offset) == '9') ||		        (sb.charAt(offset) == '.')))		    {		    if (sb.charAt(offset) == '9')		        sb.setCharAt(offset, '0') ;		    offset-- ;		    }		if (offset >= 0)		    {		    sb.setCharAt(offset,	Character.forDigit(Character.digit(sb.charAt(offset), 10) + 1, 10)) ;	t = sb.toString().substring(0, t.length() - decimals + d) ;		    }		else	t = '1' + sb.toString().substring(0, t.length() - decimals + d) ;		}	    }	if (negative)	    t = '-' + t ;	if (t.length() > w)	    pout.print(t) ;	else	    {	    for (int i = 0 ; i < w - t.length() ; i++)		pout.print(' ') ;	    pout.print(t) ;	    }	} // end of method writeDouble} // end of class BasicFileIo