CODEWITHSUNDEEP
javacommand-linejarargs
David
David

Reputation: 129

How to add path to file in Java args

i am working on one project and i come to the problem. I need to run .jar over cmnd prompt and i need to put path to .properties file into the argument, for example:

java -jar myproject.jar C:\path\to\config.properties

Now i have a path to file satatic

FileInputStream in = new FileInputStream("config\\crdb.properties");

And i need to somehow put variable instead of static path and change it with argument.

Thank you.

Upvotes: 1

Views: 7429

Answers (3)

Roshane Perera
Roshane Perera

Reputation: 132

if you are reading the property file from main method you can simply access command line arguments via args[] array public static void main(String args[]) simple code like below might do 

public static void main(String[] args) {
    String splitChar="=";

    try {

        Map<String, String> propertyList = Files.readAllLines(Paths.get(args[0]))
                .stream()
                .map(String.class::cast)
                .collect(Collectors.toMap(line -> line.split(splitChar)[0],
                        line -> line.split(splitChar)[1]));
        System.out.println(propertyList);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

or else you can pass the path as vm option

java -Dfile.path={path to config file} {JavaClassFile to execute}

and you can get the path like below (from any where in your code)

System.getProperty("file.path")

and same as in main method above you can read the property file and put it into a HashMap which I prefer

Upvotes: 0

Azzabi Haythem
Azzabi Haythem

Reputation: 2423

use -D to put your System variable and use System.getProperty to get it :

  java -Dpath.properties=C:\path\to\config.properties -jar myproject.jar 

String pathProp= System.getProperty("path.properties");
FileInputStream in = new FileInputStream(pathProp);

Upvotes: 1

Andremoniy
Andremoniy

Reputation: 34920

Simply use args array:

public static void main(String args[]) {
   try (FileInputStream in = new FileInputStream(args[0])) {
     // do stuff..
   }
}

Upvotes: 0

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