Question

I’m building a ResourceBundle from a file, this bundle holds < String, String> values.

InputStream in = getClass().getResourceAsStream('SQL.properties'); properties = new PropertyResourceBundle(in); in.close(); 

I would like to add/replace on this bundle some properties that I’m passing from the command line using -Dsome.option.val.NAME1=HiEarth

I don’t care dumping the old bundle and creating a new one instead.

Could you please tip?

I think that what I need to do is :

1. Create from the bundle a HashMap< String, String>
2. Replace values.
3. Transform the HashMap into a InputStream. //This is the complicated part…
4. Build the new bundle from that.

Answer 1

This does some of what you want (converts the System.properties to a ResourceBundle). Better error handling is left up to you 🙂

         public static ResourceBundle createBundle()     {         final ResourceBundle  bundle;         final Properties      properties;         final CharArrayWriter charWriter;         final PrintWriter     printWriter;         final CharArrayReader charReader;          charWriter = new CharArrayWriter();         printWriter = new PrintWriter(charWriter);          properties = System.getProperties();         properties.list(printWriter);          charReader = new CharArrayReader(charWriter.toCharArray());          try         {             bundle = new PropertyResourceBundle(charReader);              return (bundle);         }         catch(final IOException ex)         {             // cannot happen             ex.printStackTrace();         }          throw new Error();     }