Thread: Java program to take input from a file as a string of 3 integers separated by a space

 
import B102.*;
import java.util.*;
 
class Triangle
{
static boolean checkNumbersOnly(String input)
{
	int i;
 
	//if no input or null set to false
	if(input == null || input.length() == 0)
		return false;
 
	//loop through input and check each character is an integer
	//if a non integer is found return false
	for(i = 0; i < input.length(); i++)
	{
		if(!Character.isDigit(input.charAt(i)))
			return false;
	}
 
	return true;
 
}//End Method
 
//process method here
static String findTriangle(String input)
{
	String str1 = "an Equilateral", str2 = "an Isosceles", str3 = "a Scalene", str4 = "an Invalid";
	String output, st1, st2, st3;
	int n, temp = 0, sum = 0, n1, n2, n3, sti1, sti2, sti3;
 
	//Break the input line into tokens
	StringTokenizer st = new StringTokenizer(input);
 
	//count tokens
	n = st.countTokens();
 
	if(n == 3)
	{
		//Set tokens as variables so it can sort them into ascending order
		st1 = st.nextToken();
		st2 = st.nextToken();
		st3 = st.nextToken();
 
		//Change tokens to integers
		sti1 = Integer.parseInt(st1);
		sti2 = Integer.parseInt(st2);
		sti3 = Integer.parseInt(st3);
 
		//sort integers into ascending order
		if(sti1 > sti2)
		{
			temp = sti1;
			sti1 = sti2;
			sti2 = temp;
		}
		if(sti2 > sti3)
		{
			temp = sti2;
			sti2 = sti3;
			sti3 = temp;
		}
		if(sti1 > sti2)
		{
			temp = sti1;
			sti1 = sti2;
			sti2 = temp;
		}			
 
		//Check 1st two lengths are smaller than last length then check for triangle type
		sum = sti1 + sti2;
 
		if(sum > sti3)
		{
			if((sti1 == sti2) && (sti2 == sti3))
			{
				output = str1;
			}
		else
			if((sti1 == sti2) && (sti1 != sti3))
			{
				output = str2;
			}
			else
			{
				output = str3;
			}
		}
		else
		{
			output = str4;
		}
	}
	else
	{
		output = str4;
	}
 
	return output;
 
}//End Method		
 
//Read file name from command line
public static void main(String[] args)
{
 
textFile srcFile, dstFile;
String line, type;
boolean b = true;
int count = 0;
 
//if there are no file names on command line
if(args.length == 0)
{
	System.out.println("No filename given");
	System.exit(1);
}
 
//if there is only one file name on command line use
if(args.length == 1)
{
	//open source file on command line for reading
	srcFile = new textFile(args[0], 'r');
 
	while(!srcFile.EOF())
	{
		//read new line from file
		line = srcFile.readLine();
		count++;
 
		//check line contains only numbers
		b = checkNumbersOnly(line);
 
		if(b == true)
		{
			//get triangle type
			type = findTriangle(line);
 
			System.out.println("The lengths " + line + " make up " + type + " Triangle");
			}
			else
			{
				System.out.println("Error: line " + count + " not all inputs are integers");
			}
		}
 
		srcFile.closeFile();
	}
	else
	{
		//if there are two file names on the command line one for reading one for writing
		if(args.length == 2)
		{
			//open source file on command line for reading
			srcFile = new textFile(args[0], 'r');
 
			//open destination file for writing
			dstFile = new textFile(args[1], 'w');
 
			while(!srcFile.EOF())
			{
				//read new line from file
				line = srcFile.readLine();
				count++;
 
				//check line contains only numbers
				b = checkNumbersOnly(line);
 
				if(b == true)
				{
 
					//get triangle type
					type = findTriangle(line);
 
					dstFile.writeLine(type);
				}
				else
				{
					System.out.println("Error: line " + count + " not all inputs are integers");
				}
		}
 
		srcFile.closeFile();
		dstFile.closeFile();
 
 
		}
		else
		{
			System.out.println("Error: There are more than two files input");
			System.exit(1);
		}
	}
 
	return;
}
}

It looks neater in notepad

Basically I have to read lines from a file which contain the input stated above and validate what type of triangle it is.

It was a file from the uni it contains some classes I would be using.