Apache Commons Configurations containsKey returns false on existing key

Question

Apologies if this is documented, but I wasn't able to find this on the official documentation.

I'm using XMLConfiguration to load this file, but config.containsKey ("aliases") returns false and config.containsKey ("aliases.alias") returns true. Am I forced to check for "aliases.alias" or is there a way to determine if "aliases" exists as node?

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <name>Vocabulary</name>
    <aliases>
        <alias>Dictionary</alias>
    </aliases>
    <extensions>
        <ext>dic</ext>
        <ext>txt</ext>
        <ext>pdf</ext>
        <ext>doc</ext>
    </extensions>
    <scanmode>1</scanmode>
</configuration>

To investigate better can you provide your actual java code. — Karuna, Oct 01 '15 at 23:19
@Karuna I only open the XML configuration using XMLConfiguration and call containsKey method — Vektor88, Oct 01 '15 at 23:27

score 3 · Accepted Answer · edited Jul 21 '16 at 17:52

You can use HierarchicalConfiguration to check the if the node exists or not.

if(!config.configurationAt("aliases").isEmpty())

containsKey() It is working as expected. public boolean containsKey(String key) Checks if the specified key is contained in this configuration. Note that for this configuration the term "contained" means that the key has an associated value. If there is a node for this key that has no value but children (either defined or undefined), this method will still return FALSE.

here is code import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.XMLConfiguration;

public class HirerarchicalConfig{

    public static boolean checkIfNodeExists(String nodeName,XMLConfiguration config){       
        if(!config.configurationAt(nodeName).isEmpty())
            return true;
        else 
            return false;       
    }   
    public static void main(String[] args) throws ConfigurationException{       

        XMLConfiguration config = new XMLConfiguration("configFile.xml");
        boolean aliasesNode = checkIfNodeExists("aliases",config);
        System.out.println(aliasesNode);        
    }
}

score 0 · Answer 2 · answered Aug 21 '17 at 14:42

0

Actually you need to use

if(!config.configurationsAt("aliases").isEmpty())

or else you get an exception like this one

org.apache.commons.configuration2.ex.ConfigurationRuntimeException: Passed in key must select exactly one node: aliases

answered Aug 21 '17 at 14:42

miguel_rdp

17
3

Apache Commons Configurations containsKey returns false on existing key

2 Answers2