Simple File extension program

[Deepwoods]

I'm having trouble getting this program to display output. Please tell me what is wrong with the code provided.

N is the number of media type associations and Q is the number of filenames and they will be given as numbers on first line of input.

INPUT:
Following this are N lines, each containing a file extension and a media type, separated by a space. Finally, Q lines, each containing the name of a file.

OUTPUT:
For each of the Q file names, print on a line the media type of the file. If there is no matching entry, print "unknown" (quotes for clarity).

Sample Input

5 6
html text/html
htm text/html
png image/png
svg image/svg+xml
txt text/plain
index.html
this.file.has.lots.of.dots.txt
nodotsatall
virus.exe
dont.let.the.png.fool.you
case.matters.TXT

Sample Output

text/html
text/plain
unknown
unknown
unknown
unknown

import java.util.Scanner;
import java.lang.String;
class sumNQ
{
public static void main(String args[])
{
Scanner s=new Scanner(System.in);
System.out.println("enter N and Q :");
String NQ=s.nextLine();
Scanner snum = new Scanner(NQ).useDelimiter(" ");//for getting the number of file types n and number of filenames q
int n=snum.nextInt();
int q=snum.nextInt();
int sumnq=n+q; // sum of total number of lines in input

String[] strarr = new String[sumnq]; // array of strings with each element containing a line of input
int i=0;
while(i<sumnq)
{
strarr[i]=s.nextLine();
i++;
}

String[][] strN = new String[n][2]; // 2d array of strings containing filetype in first element and mediatype in second element of first dimension
for(int j=0;j<n;j++)
{
Scanner strarrstr=new Scanner(strarr[j]).useDelimiter(" ");
strN[j][0]=strarrstr.next();
strN[j][1]=strarrstr.next();
}

String res="";
for(int m=n;m<sumnq;m++) // for iterating filenames starting at index n of strarr
{
String stest=strarrAfterPeriod(strarr[m]);
for(int l=0;l<n;l++) // for testing filenames starting at n with filetypes starting at 0 of strarr
{
if(stest.equals(strN[l][0])) // comparison
{
res+=strN[l][1]+"\n"; // output string
}
else if(l==n)
res=res+"unknown\n";
}}
System.out.println(res);
}

public static String strarrAfterPeriod(String str) // for fetching the string after last period of filename
{
Scanner speriod=new Scanner(str).useDelimiter(".");
String sper=speriod.next();
while(speriod.hasNext())
sper=speriod.next();
return sper;
}}

[pbrockway2]

The code tags are [code] ...[/code]

[Deepwoods]

The code tags are [code] ...[/code]

Thanks for the info.

[pbrockway2]

It's not your whole problem, but

for(int m=n;m<sumnq;m++) 
{
    String stest=strarrAfterPeriod(strarr[m]);
    for(int l=0;l<n;l++)
    {
        if(stest.equals(strN[l][0])) 
        {
            res+=strN[l][1]+"\n"; 
        }
        else if(l==n)  // <----- this condition can never be true
            res=res+"unknown\n";
    }
}

You would help yourself if you followed some standard coding conventions: start the class name with a capital letter, make variable names descriptive and never use l, use braces even around one line blocks of code.

Also, check everything. Eg, use System.out.println() to see what strarrAfterPeriod() is actually returning (and what you are passing to it), otherwise if is not doing what you expect you won't ever know that.