[LANG-596] StrSubstitutor should also handle the default properties of a java.util.Properties class

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.5
• Fix Version/s: 3.0
• Component/s: lang.text.*
• Assignee: Unassigned
• Reporter: Ulrich Voigt
• Created: 01/Mar/10 12:17
• Updated: 29/Aug/10 22:54
• Resolved: 29/Aug/10 22:54

Description

The following program show a problem with a shortcoming of the java.util.Properties class.
The default properties are not substituted by the StrSubstitutor.

StrSubstTest.java

import org.apache.commons.lang.text.StrSubstitutor;

public class StrSubstTest
{
    public static void main(String[] args)
    {
        String org = "${doesnotwork}";
        System.setProperty("doesnotwork", "It work's!");

        // create a new Poperties object with the System.getProperties as default
        Properties props = new Properties(System.getProperties());

        String subst = StrSubstitutor.replace(org, props);
        // is ${doesnotwork} substituted?
        System.out.println(subst);

    }
}

The following method could be added to the StrSubstitutor class to fix this problem in an easy way:

    /**
     * Replaces all the occurrences of variables in the given source object with their matching
     * values from the properties.
     * 
     * @param source the source text containing the variables to substitute, null returns null
     * @param properties the properties with values, may be null
     * @return the result of the replace operation
     */
    public static String replace(Object source, Properties valueProperties)
    {
        if (valueProperties == null) {
            return source;
        }
        Map valueMap = new HashMap();
        Enumeration propNames = valueProperties.propertyNames();
        while (propNames.hasMoreElements())
        {
            String propName = (String)propNames.nextElement();
            String propValue = valueProperties.getProperty(propName);
            valueMap.put(propName, propValue);
        }
        return StrSubstitutor.replace(source, valueMap);
    }