export java application with csv file

Question

I have one java application in which I have used two excel files (.csv files) as a input.I want to make runnable jar of that java application.But after exporting that java project as a runnable jar when I run that jar it does not contain the two input csv files.

Can any one help me how to export java application with csv files.

Below is the line of code I have used to access the csv file

  String csvFile = "./input/silkair.Schedule1 (1).csv";

 //InputStream inputStream = getClass().getResourceAsStream(csvFile);
    BufferedReader br = null;


//          br = new BufferedReader(new InputStreamReader(inputStream));
            br = new BufferedReader(new FileReader(csvFile));

they were in project folder first. I have just tried them put in separate folder but it still not working — rachana, Nov 17 '14 at 12:45
@atish shimpi Yes I have added those files in my project folder.But it still not working after exporting the projkt — rachana, Nov 17 '14 at 12:47
refer link http://stackoverflow.com/questions/2671796/how-to-include-text-files-with-executable-jar — atish shimpi, Nov 17 '14 at 13:00
@atish shimpi thanks for the link.But I have already referred it.It does not help me — rachana, Nov 17 '14 at 13:13

ewan.chalmers · Answer 1 · 2014-11-17T13:39:48.880

If you want to read the CSV files from the jar, then they must be included in the jar. Check using jar tvf your.jar or a zip utility. If reading files from the jar, use InputStreamReader with getResourceAsStream.

If you want to read the CSV files from the file system, then you need to have them on the file system, not in the jar (or extract them from the jar before running...). If reading files from file system, use FileReader with file system filename.

Here is a demonstration...

Two source files - one reading from jar, one reading from filesystem:

$ cat ReadFile.java
import java.io.*;
public class ReadFile {
public static void main(String[] args) throws IOException {
        String csvFile = args[0];
        BufferedReader reader = new BufferedReader(new FileReader(csvFile));
        String line;
        while((line = reader.readLine()) != null) {
                System.out.println(line);
        }
}
}

$ cat ReadResource.java
import java.io.*;
public class ReadResource {
public static void main(String[] args) throws IOException {
        String csvFile = args[0];
        BufferedReader reader = new BufferedReader(new InputStreamReader(ReadResource.class.getResourceAsStream(csvFile)));
        String line;
        while((line = reader.readLine()) != null) {
                System.out.println(line);
        }
}
}

The content of the jar - CSV file at _input_/my.csv:

$ jar tvf readtest.jar
     0 Mon Nov 17 12:58:04 GMT 2014 META-INF/
    71 Mon Nov 17 12:58:04 GMT 2014 META-INF/MANIFEST.MF
   697 Mon Nov 17 12:52:30 GMT 2014 ReadFile.class
   842 Mon Nov 17 12:52:30 GMT 2014 ReadResource.class
     0 Mon Nov 17 12:47:38 GMT 2014 _input_/
    16 Mon Nov 17 12:47:20 GMT 2014 _input_/my.csv

The content of the file system - CSV file at input/my.csv:

$ mv _input_/ input
$ find .
.
./input
./input/my.csv
./ReadFile.class
./ReadFile.java
./ReadResource.class
./ReadResource.java
./readtest.jar

Using ReadFile, you can read from file system, but not from jar:

$ java -cp readtest.jar ReadFile input/my.csv
foo,bar
bar,foo

$ java -cp readtest.jar ReadFile _input_/my.csv
Exception in thread "main" java.io.FileNotFoundException: _input_\my.csv (The system cannot find the path specified)
        at java.io.FileInputStream.open(Native Method)
        at java.io.FileInputStream.<init>(FileInputStream.java:106)
        at java.io.FileInputStream.<init>(FileInputStream.java:66)
        at java.io.FileReader.<init>(FileReader.java:41)
        at ReadFile.main(ReadFile.java:5)

Using ReadResource, you can read from jar, but not from file system:

$ java -cp readtest.jar ReadResource input/my.csv
Exception in thread "main" java.lang.NullPointerException
        at java.io.Reader.<init>(Reader.java:61)
        at java.io.InputStreamReader.<init>(InputStreamReader.java:55)
        at ReadResource.main(ReadResource.java:5)

$ java -cp readtest.jar ReadResource _input_/my.csv
foo,bar
bar,foo

In that case the CSV files should not be in your jar. If you want to read from file system, you need to put them on the file system. You could extract them from your jar if they are in it. — ewan.chalmers, Nov 17 '14 at 13:25

export java application with csv file

1 Answers1