CODEWITHSUNDEEP
javaproperties
hoaz
hoaz

Reputation: 10153

Filter out comments when writing Properties to a file

I am using java.util.Properties#store() method to save my properties to a file:

os = new BufferedOutputStream(new FileOutputStream(propertiesFile));
properties.store(os, null);

Default implementation of this method always writes comment as the first line with current timestamp:

#Thu May 16 12:55:36 EDT 2013

This behavior is not desired in my application as I need to track all changes in my properties file. Is it possible to filter this comment line (and all others) from property file somehow?

I am particularly interested in "on the fly" solution without post processing of the file afterwards.

Upvotes: 2

Views: 427

Answers (3)

AlexR
AlexR

Reputation: 115328

Yes, you can :).

First, you can extend Properties and override store() method. But this way is too complicated.

You can do better. Examine source code of store(). It calls private method store() that actually does the work. This method calls

bw.write("#" + new Date().toString());

in the beginning. You do not want to see this line. This means that you have to implement your own BufferedWriter that ignores the first printed line. 

public class IgnoreFirstLineBufferedWriter extends BufferedWriter {
    private int lineCouner = 0;
    // constructors - implement them yourself

    @Override
    public void write(String str) throws IOException {
        if (lineCounter > 0) {
            super.write(str);
        }
        lineCounter++;
    }
}

Now you can use this customized BufferedWriter when you are wrapping your FileOutputStream and calling store():

props.store(new IgnoreFirstLineBufferedWriter(new OutputStreamWriter(new FileOutputStream("myprops.properties"))));

Upvotes: 2

Bitman
Bitman

Reputation: 2006

Date is not printed when you use storeToXML method. But properties will be stored in XML( Otherwise the best way to do it is to extend Properties class as explained before

Upvotes: 0

Juned Ahsan
Juned Ahsan

Reputation: 68715

This timestamp is printed in private method on Properties and there is no property to control that behaviour. If you want to change this behavior then you may need to subclass Properties, overwrite store method and copy/paste the content of the store0 method so that the date comment will not be printed.

Upvotes: 0

Related Questions