storing Hexadecimal value in Java properties file without "\"

Question

I'm trying to add hexadecimal value in a property file, the value is getting stored but i can see a "\" getting appended, which I don't want,

test.properties

#
#Fri Jun 07 21:18:49 GMT+05:30 2013
test=fe\:fe

the Java file

public class PropertySave {
    private static File s_file;
    private static Properties s_properties = new Properties();
    public static void main(String[] args) {
        loadProperties();
        s_properties.setProperty("test", "fe:fe");
        saveProperties();
    }
    private static void saveProperties() {
        FileOutputStream fout = null;
        try {
            fout = new FileOutputStream(s_file);
            s_properties.store(fout, "");
        } catch (IOException ioe) {
            ioe.printStackTrace();
            System.exit(1);
        } finally {
            if (fout != null) {
                try {
                    fout.close();
                } catch (final IOException ioe2) {
                    ioe2.printStackTrace();
                    System.exit(1);
                }
            }
        }
    }
    private static void loadProperties() {
        s_file = new File("test.properties");
        if ((!s_file.exists()) || (!s_file.isFile())) {
            System.exit(1);
        }
        FileInputStream fin = null;
        try {
            fin = new FileInputStream(s_file);
            s_properties.load(fin);
        } catch (IOException ioe) {
            ioe.printStackTrace();
            System.exit(1);
        } finally {
            if (fin != null) {
                try {
                    fin.close();
                } catch (final IOException ioe2) {
                    ioe2.printStackTrace();
                    System.exit(1);
                }
            }
        }
    }
}

In java file the s_properties.setProperty("test", "fe:fe"); the output in property file is different(test.properties) fe:fe this i want to ignore as this property file is input to other system in "C" Language because of which my things are not working,

What Should I do to make sure the input in java file and output in properties file will same

Answer 1

Consider encoding the hexidecimal values in a known way and decoding them in both C and Java.

One technique is to precede the hexidecimal value with "0x" and use all upper case for the digits. If you use this technique, you will need some way to signal the end of a hexidecimal number. I suggest a space character (' ') or end of line.

With this technique, your property will look like this:

test=0xFEFE

The string "Blam07kapow" where 07 is a hex number would look like this:

Blam0x07 kapow

Answer 2

The Properties class stores : with a preceding \ in order to ensure that it will load the proper value again when you use the load method. If you want to be able to load in this properties file back into java later on, then I'm afraid you are stuck with the escape character in your properties file. See java.util.Properties documentation