CODEWITHSUNDEEP
javagunzip
chrisTina
chrisTina

Reputation: 2378

Permission denied when gunzip a file in Java

Given the following codes I use to gunzip a '.gz' file:

public class TestCSVDataToMap {
    private static final String INPUT_GZIP_FILE = "/opt/old.csv.gz";
    private static final String OUTPUT_FILE = "/opt/new.csv";
    public static void main(String[] args) throws IOException{
        TestCSVDataToMap dm = new TestCSVDataToMap();
        dm.gunzipIt();
    }

public void gunzipIt(){

     byte[] buffer = new byte[1024];

     try{

         GZIPInputStream gzis = 
            new GZIPInputStream(new FileInputStream(INPUT_GZIP_FILE));

         FileOutputStream out = 
            new FileOutputStream(OUTPUT_FILE);

        int len;
        while ((len = gzis.read(buffer)) > 0) {
            out.write(buffer, 0, len);
        }

        gzis.close();
        out.close();

        System.out.println("Done");

    }catch(IOException ex){
       ex.printStackTrace();   
    }
   } 

}

throws out such an exception:

java.io.FileNotFoundException: /opt/new.csv (Permission denied)

this is because the path '/opt' are not allowed to make any changes. But I can use

sudo gunzip /opt/old.csv.gz

to unzip the file. So in Java, what should I do to act like a 'sudo'?

Upvotes: 0

Views: 1112

Answers (2)

Jean-Baptiste Yunès
Jean-Baptiste Yunès

Reputation: 36431

There is no standard way to sudo in Java. But you can sudo your Java program sudo java TestCSVDataToMap.

Java isn't designed to manage OS process access rights.

Upvotes: 1

Elliott Frisch
Elliott Frisch

Reputation: 201497

Start your java process with sudo

sudo java -jar myjar.jar

Or, write to a folder you do have permission to write to (like /tmp or $HOME).

Upvotes: 0

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