read csv file and make array

[bela]

Hello,

I am very new to JAVA.

I would like to know, how to read *.csv file from java and how to save that data into an array.

regards,
bela

[bela]

Hi,
First download the javacsv.jar. After that read a bit about csvReader API.
http://opencsv.sourceforge.net/api/a...CSVReader.html

thank you.
But I'm not able to convert in / store as in array form.

regards,
bela

[madhoriya22]

thank you.
But I'm not able to convert in / store as in array form.

regards,
bela

Hi,
Show us a bit what u have tried ? Then only we vil be able to help you.

[snowfall]

Hi, I tried an Example but am not able to read the file.
My Code is,

mport com.csvreader.C svReader;
import java.io.*;
class csveg
{
public static void main(String a[])
{
try
{
CsvReader cs=new CsvReader("hi.c sv");
System.out.prin tln("hiii "+ cs);
System.out.prin tln("hiii "+ cs.getColumnCou nt());//Prints 0
String arra[]=cs.getValues() ;
System.out.prin tln("hiii "+arra.leng th);//Prints 0
for(int j=0;j<arra.leng th;j++)
{
System.out.prin tln("hiii "+j);
System.out.prin tln(arra[j]);
}


}catch(Exceptio n e){System.out.p rintln("Excepti on is ");}
}
}

pls help...

[madhoriya22]

Hi, I tried an Example but am not able to read the file.
My Code is,

mport com.csvreader.C svReader;
import java.io.*;
class csveg
{
public static void main(String a[])
{
try
{
CsvReader cs=new CsvReader("hi.c sv");
System.out.prin tln("hiii "+ cs);
System.out.prin tln("hiii "+ cs.getColumnCou nt());//Prints 0
String arra[]=cs.getValues() ;
System.out.prin tln("hiii "+arra.leng th);//Prints 0
for(int j=0;j<arra.leng th;j++)
{
System.out.prin tln("hiii "+j);
System.out.prin tln(arra[j]);
}


}catch(Exceptio n e){System.out.p rintln("Excepti on is ");}
}
}

pls help...

Hi,
If u hav not read the API for method getColumnCount( ) .. then check it again and try understand what it is saying ....
It is saying that "Gets the count of columns found in this record".

Here U hav get the file in the csvReader but havn't started reading it ... So start reading the file then only this method vil give u the column count for the particular record u r reading.

I hope u r getting my point.

[bela]

Hi,
Show us a bit what u have tried ? Then only we vil be able to help you.

yes, my code is :

import java.io.*;
import au.com.bytecode .opencsv.CSVRea der;

public class csv2array {

private static final String data = "e:\\weather.cs v";

public static void main(String[] args) throws IOException {

CSVReader reader = new CSVReader(new FileReader(data ),',','\'',1);
String [] nextLine;
int cnt=0;
String[][] str1= new String[14][5];

while ((nextLine = reader.readNext ()) != null) {
System.out.prin tln("Row no is : " + cnt);
System.out.prin tln(nextLine[0]+',' + nextLine[1]+','+ nextLine[2]+',' +nextLine[3]+','+nextLine[4]);
for(int n=0;n<14;n++){
for(int rowelement=0;ro welement<5;rowe lement++){
str1[n][rowelement]=nextLine[rowelement];
}
}
cnt++;
}

}
}

weather.csv is available on WEKA.
I'm taking data in matrix str1.
How to see the containts of str1?
when I tried, System.out.prin tln(str1); it gives address of str1.

regards,
bela

[madhoriya22]

yes, my code is :

import java.io.*;
import au.com.bytecode .opencsv.CSVRea der;

public class csv2array {

private static final String data = "e:\\weather.cs v";

public static void main(String[] args) throws IOException {

CSVReader reader = new CSVReader(new FileReader(data ),',','\'',1);
String [] nextLine;
int cnt=0;
String[][] str1= new String[14][5];

while ((nextLine = reader.readNext ()) != null) {
System.out.prin tln("Row no is : " + cnt);
System.out.prin tln(nextLine[0]+',' + nextLine[1]+','+ nextLine[2]+',' +nextLine[3]+','+nextLine[4]);
for(int n=0;n<14;n++){
for(int rowelement=0;ro welement<5;rowe lement++){
str1[n][rowelement]=nextLine[rowelement];
}
}
cnt++;
}

}
}

weather.csv is available on WEKA.
I'm taking data in matrix str1.
How to see the containts of str1?
when I tried, System.out.prin tln(str1); it gives address of str1.

regards,
bela

Hi,
If u hav done all this hard work urself then printing array values should not be a problem :) ur str1 is a two dimensional array. For reading values in that u hav to put two for loops like..

for(int i = 0; i < 14; i++) {
    for(int j = 0; j < 5; j++) {//obviously u can get row and column lenghts by using str1.length.
     System.out.println(str1[i][j]);
    }
}
 

[bela]

Hi,
If u hav done all this hard work urself then printing array values should not be a problem :) ur str1 is a two dimensional array. For reading values in that u hav to put two for loops like..

for(int i = 0; i < 14; i++) {
    for(int j = 0; j < 5; j++) {//obviously u can get row and column lenghts by using str1.length.
     System.out.println(str1[i][j]);
    }
}
 

yes, this I've tried, and also know this method. But here it prints element by element. my final aim is to make new matrix by extracting few rows and column of this str1 matrix, where I need entire row/ entire column.
using for loops, I can do it,
but I was searching for different method if there is as this will be lengthy procedure.
I have to create those many arrays/matrices.
Do you know any other method?

[snowfall]

Hi,
If u hav not read the API for method getColumnCount( ) .. then check it again and try understand what it is saying ....
It is saying that "Gets the count of columns found in this record".

Here U hav get the file in the csvReader but havn't started reading it ... So start reading the file then only this method vil give u the column count for the particular record u r reading.

I hope u r getting my point.

Ya got it.. Now its executing.. Thnks

[madhoriya22]

Ya got it.. Now its executing.. Thnks

Hi,
Ofcourse Welcome Buddy :)

[madhoriya22]

yes, this I've tried, and also know this method. But here it prints element by element. my final aim is to make new matrix by extracting few rows and column of this str1 matrix, where I need entire row/ entire column.
using for loops, I can do it,
but I was searching for different method if there is as this will be lengthy procedure.
I have to create those many arrays/matrices.
Do you know any other method?

Hi,
Check my post #7. Go to that link. That CsvReader API has more methods than the one which u are using. By Using methods of this u can skip the records which u don't want to read.

Tip: Dont be rude while asking, sharing or answering. Always be thankful :)