Source code for MyFieldParserExample.java:

import java.text.ParseException;
public class MyFieldParserExample
{
	public String myFieldParser(String inputStr)
		throws ParseException
	{
		int colon = inputStr.indexOf(':');
		if(colon == -1) // simple test for ':'
		{
			throw new ParseException(inputStr, inputStr.length() -1 );
		}
		// found a colon, we are safe to continue parsing
		// ...
		// This next line wasn't in the book, and could be
		// any parsing.  We picked the substring up to, but
		// not inluding, the colon.
		String parsedString = inputStr.substring(0, colon);
		return(parsedString);
	}
	
	public void testValue(String s)
	{
		String beforeColon = null;
		try
		{
			beforeColon = myFieldParser(s);
		}
		catch (ParseException e)
		{
			System.out.println(e);
			e.printStackTrace();
			// You could do more here.
		}
	}
	
	public static void main(String args[])
	{
		MyFieldParserExample ex = new MyFieldParserExample();
		ex.testValue("This is good:it has a colon.");
		ex.testValue("This is bad.  It does not have a colon.");
	}
}

Output from MyFieldParserExample.java:

java.text.ParseException: This is bad.  It does not have a colon.
java.text.ParseException: This is bad.  It does not have a colon.
	at java.lang.Throwable.fillInStackTrace(Native Method)
	at java.lang.Throwable.(Throwable.java:94)
	at java.lang.Exception.(Exception.java:42)
	at java.text.ParseException.(ParseException.java:54)
	at MyFieldParserExample.myFieldParser(MyFieldParserExample.java:10)
	at MyFieldParserExample.testValue(MyFieldParserExample.java:26)
	at MyFieldParserExample.main(MyFieldParserExample.java:40)

--- Output Ends ---

NOTE:

To run this program:

• javac MyFieldParserExample.java
• java MyFieldParserExample