import java.io.*; /** * @author Gary Litvin * @version 1.2, 5/30/02 * * Written as part of * * Java Methods: An Introduction to Object-Oriented Programming * (Skylight Publishing 2001, ISBN 0-9654853-7-4) * * and * * Java Methods AB: Data Structures * (Skylight Publishing 2003, ISBN 0-9654853-1-5) * * EasyReader provides simple methods for reading the console and * for opening and reading text files. All exceptions are handled * inside the class and are hidden from the user. * *
null
character
* (Unicode 0) if trying to read beyond the EOF
*/
public char readChar()
{
char ch = '\u0000';
try
{
if (ready())
{
ch = (char)myInFile.read();
}
}
catch (IOException e)
{
if (myFileName != null)
System.err.println("Error reading " + myFileName + "\n");
myErrorFlags |= READERROR;
}
if (ch == '\u0000')
myErrorFlags |= EOF;
return ch;
}
/**
* Reads from the current position in the file up to and including
* the next newline character. The newline character is thrown away
* @return the read string (excluding the newline character) or
* null if trying to read beyond the EOF
*/
public String readLine()
{
String s = null;
try
{
s = myInFile.readLine();
}
catch (IOException e)
{
if (myFileName != null)
System.err.println("Error reading " + myFileName + "\n");
myErrorFlags |= READERROR;
}
if (s == null)
myErrorFlags |= EOF;
return s;
}
/**
* Skips whitespace and reads the next word (a string of consecutive
* non-whitespace characters (up to but excluding the next space,
* newline, etc.)
* @return the read string or null if trying to read beyond the EOF
*/
public String readWord()
{
StringBuffer buffer = new StringBuffer(128);
char ch = ' ';
int count = 0;
String s = null;
try
{
while (ready() && Character.isWhitespace(ch))
ch = (char)myInFile.read();
while (ready() && !Character.isWhitespace(ch))
{
count++;
buffer.append(ch);
myInFile.mark(1);
ch = (char)myInFile.read();
};
if (count > 0)
{
myInFile.reset();
s = buffer.toString();
}
else
{
myErrorFlags |= EOF;
}
}
catch (IOException e)
{
if (myFileName != null)
System.err.println("Error reading " + myFileName + "\n");
myErrorFlags |= READERROR;
}
return s;
}
/**
* Reads the next integer (without validating its format)
* @return the integer read or 0 if trying to read beyond the EOF
*/
public int readInt()
{
String s = readWord();
if (s != null)
return Integer.parseInt(s);
else
return 0;
}
/**
* Reads the next double (without validating its format)
* @return the number read or 0 if trying to read beyond the EOF
*/
public double readDouble()
{
String s = readWord();
if (s != null)
return Double.parseDouble(s);
// in Java 1, use: return Double.valueOf(s).doubleValue();
else
return 0.0;
}
}