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May 24th, 2011, 01:33 PM
#1
From String array to int array throwing ','and null from text file
hey every one
i developed a code to read a text file and put the integers in array but i had a problem to convert the string array to int array throwing any thing else except the imts ,
this is the content of the text file
5
1,10
8,10
10,8
7,4
3,1
0,1,10
1,2,5
2,3,25
0,3,3
3,4,8
this my code
import java.io.*;
import java.util.*;
*
public class Read {
public static void main (String[] args) throws FileNotFoundException, IndexOutOfBoundsException , IOException, Exception {
System.out.println("Enter a filepath to copy from, and one to copy to.");
Scanner in = new Scanner(System.in);
String a=in.next();
File f = new File (a);
FileInputStream FF = new FileInputStream(f);
BufferedReader br = new BufferedReader(new InputStreamReader(FF));
BufferedReader brr = new BufferedReader(new FileReader(a));
String line;
int linecount =0 ;
while ((line = brr.readLine()) != null) {
linecount++;
}
char [] k = null;
String [] s = null ;
s = new String[50];
int [] dd = null ;
char [] d = null;
for (int j = 0; j < linecount; j++){
s[j] = br.readLine();
}
FF.close();
}
}
==========================================================
i tried with many ways to convert that string array to int array so the int array well be like
{5,1,10,8,10,10,8,7,4,3,1,0,1,10,1,2,5,2,3,25,0,3,3,3,4,8}
i used cahrtat method and parseint method but it doesnt work
Can any one help me with this
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May 24th, 2011, 04:28 PM
#2
Re: From String array to int array throwing ','and null from text file
I used cahrtat method and parseint method but it doesnt work
What does "doesnt' work" mean?
If you get errors, please copy and paste the full text of the error messages here.
Norm
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May 24th, 2011, 05:03 PM
#3
Re: From String array to int array throwing ','and null from text file
thanks for responding
this is what i get when i use parseint
Enter a filepath to copy from, and one to copy to.
C:\Users\F.A.M\Desktop\GGGGGGGGG\tr.txt
Exception in thread "main" java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:470)
at java.lang.Integer.parseInt(Integer.java:499)
at s.Read.convertStringArraytoIntArray(Read.java:20)
at s.Read.main(Read.java:64)
Java Result: 1
BUILD SUCCESSFUL (total time: 7 seconds)
===============
when i use a char array to move every strings to like
String [] s = null ;
s = new String[50];
char [] dd = null ;
char [] d = null;
int t=0;
for (int j = 0; j < linecount; j++){
s[j] = br.readLine();
}
for (int j = 0; j < linecount; j++){
d=s[j].toCharArray();
for (int y=0 ; y<=d.length ; y++){
dd[t]=d[y] ;
}
}
Exception in thread "main" java.lang.NullPointerException
or
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
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May 24th, 2011, 05:07 PM
#4
Re: From String array to int array throwing ','and null from text file
You should look at the String before trying to convert it to an int.
The error message says that the String was empty. For input string: ""
Exception in thread "main" java.lang.NullPointerException
or
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
Post the FULL text of error messages and the source code that caused it.
What you posted is basically useless without the source code line number.
Where is the array dd given a value? For example dd = new char[400];
To break your input data up into tokens look at the StringTokenizer class
or the String split method.
Last edited by Norm; May 24th, 2011 at 05:11 PM.
Reason: How to parse String to tokens
Norm
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May 24th, 2011, 05:23 PM
#5
Re: From String array to int array throwing ','and null from text file
the problem is that netbeans wont let me copy line numbers and i put an index value index value
and thats what i get
Enter a filepath to copy from, and one to copy to.
C:\Users\F.A.M\Desktop\GGGGGGGGG\tr.txt
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at s.Read.main(Read.java:68)
Java Result: 1
BUILD SUCCESSFUL (total time: 50 seconds)
code
char [] dd = new char [500] ;
char [] d = new char [500];
int t=0;
61: for (int j = 0; j < linecount; j++){
62: s[j] = br.readLine();
63: }
64: for (int j = 0; j < linecount; j++){
65: d=s[j].toCharArray();
66: for (int y=0 ; y<=d.length ; y++){
67: if (d != null){
68: dd[t]=d[y] ;
}
}
}
then i changed all initial values to 1 and same error message
is there any better you think to solve this problem
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May 24th, 2011, 05:34 PM
#6
Re: From String array to int array throwing ','and null from text file
What are the values of s[j], t, y and the length of d when line 68 is executed?
Add printlns to show the values
Last edited by Norm; May 24th, 2011 at 05:36 PM.
Norm
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May 24th, 2011, 05:48 PM
#7
Re: From String array to int array throwing ','and null from text file
i should delete line 69 that cause the error otherwise it wont print any thing
this the code after deleting the error line (t will not change == remain 0)
for (int j = 0; j < linecount; j++){
s[j] = br.readLine();
}
for (int j = 0; j < linecount; j++){
d=s[j].toCharArray();
System.out.println(s[j]);
for (int y=0 ; y<=d.length ; y++){
System.out.println(y);
}
}
System.out.println("==========");
System.out.println(linecount);
FF.close();
}
}
OUTPUT
Enter a filepath to copy from, and one to copy to.
C:\Users\F.A.M\Desktop\GGGGGGGGG\tr.txt
0
5
0
1
1,10
0
1
2
3
4
8,10
0
1
2
3
4
10,8
0
1
2
3
4
7,4
0
1
2
3
3,1
0
1
2
3
0,1,10
0
1
2
3
4
5
6
1,2,5
0
1
2
3
4
5
2,3,25
0
1
2
3
4
5
6
0,3,3
0
1
2
3
4
5
3,4,8
0
1
2
3
4
5
==========
12
BUILD SUCCESSFUL (total time: 12 seconds)
THANK FOR BEING SO PATIENT WITH ME NORM
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May 24th, 2011, 05:50 PM
#8
Re: From String array to int array throwing ','and null from text file
Glad you're making progress.
Remember to test the values of data you read in to be sure its what you want.
Norm
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May 24th, 2011, 05:56 PM
#9
Re: From String array to int array throwing ','and null from text file
put i didnt get how to move these numbers to separate array without the comma ',' and without errors falling on me Its very complicated you know
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May 24th, 2011, 07:40 PM
#10
Re: From String array to int array throwing ','and null from text file
Look at the String split method.
Norm
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