CODEWITHSUNDEEP
javadesign-patternsproperties
adhg
adhg

Reputation: 10863

better way to point to folders and files in a properties file?

I was wondering if there is a better way to have a point to PATH in a properties file. Consider the following code:

public class Properties
{ 
     //MIKE
     public final static String PATH_TO_FILE_A = "C:\\programmer_MIKE\fileA.txt";
     public final static String PATH_TO_FILE_B = "C:\\programmer_MIKE\fileB.txt";

     //BILL
     //public final static String PATH_TO_FILE_A = "/Users/BILL/Desktop/fileA.txt";
     //public final static String PATH_TO_FILE_B = "/Users/BILL/Desktop/fileB.txt";
}

when any developer need to invoke FILE_A he simply does:

File file = new File(Properties.PATH_TO_FILE_A);

this works ok for BILL if he commented out MIKE's PATH_TO_FILE_A.

Q: is there a better design? If BILL committed his work including the Properties file - he will cause a problem to MIKE (no worries, he'll get a Coffee Latte later on).

Thanks for any pointer!

Upvotes: 0

Views: 107

Answers (3)

Ankit Zalani
Ankit Zalani

Reputation: 3168

Normally paths are configurable entites and should be stored in property file.

Property files has a build in support in java and it uses Properties object for storing that information.

You can read the property file at startup or init (or similar) method of your application and read the proeprties from property file. This will make your configuration dynamic and anyone would be able to change it.

You can create a static method and call it on startup like:

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;


public class GetProperties {
    public static Properties prop = new Properties();

    public static void init() {

        InputStream inputStream = GetProperties.class.getClassLoader().getResourceAsStream("application.properties");
        try {
            prop.load(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }       
    }
}

Upvotes: 1

R Campbell
R Campbell

Reputation: 170

If for whatever reason you really must have hardcoded paths, then you could store them in some kind of map indexed by username. Something like:

public class Properties {

    private static Map<String, DeveloperPaths> properties = create();

    private static Map<String, DeveloperPaths> create() {

        Map<String, DeveloperPaths> properties = new HashMap<String, DeveloperPaths>();

        properties.put("mike", new DeveloperPaths(
                "C:\\programmer_MIKE\fileA.txt", 
                "C:\\programmer_MIKE\fileB.txt")
                );

        properties.put("bill", new DeveloperPaths(
                "/Users/BILL/Desktop/fileA.txt", 
                "/Users/BILL/Desktop/fileB.txt")
                );

        return properties;
    }

    public static File FileA()
    {
        String user = System.getProperty("user.name");
        return properties.get(user).fileA;
    }

    public static File FileB()
    {
        String user = System.getProperty("user.name");
        return properties.get(user).fileB;
    }

}

 class DeveloperPaths {
    public File fileA;
    public File fileB;

    public DeveloperPaths(String pathA, String pathB) {
        fileA = new File(pathA);
        fileB = new File(pathB);
    }
}

Then, the code to access each path would be identical regardless of developer, for example:

File myFile = Properties.fileA();

Upvotes: 2

Dave Newton
Dave Newton

Reputation: 160191

Things like this should be configured externally and/or passed in via parameter, system parameter, or environment variable. Alternatively you could use DI/IoC, but when there's no attached behavior, IMO a config value is plenty.

It's fine to have a hard-coded default, but otherwise stuff like this doesn't belong in code.

Upvotes: 0

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