[TAMAYA-235] The get method of the MappedConfiguration class may throw a NullPointerException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.2-incubating
• Fix Version/s: 0.3-incubating
• Component/s: Extensions
• Labels: tamaya-clarifying-03 tamaya-wating-response
• Assignee: Anatole Tresch
• Reporter: Francois MESSIAEN
• Created: 02/Feb/17 17:55
• Updated: 18/Sep/17 19:35
• Resolved: 26/Feb/17 22:48

Description

When the parameter "stripKeys" is set true in the section method of the ConfigurationFunctions class, the behavior of the get method MappedConfiguration is incoherent : the section name has to be prepend twice in order to get the value.

The following code source is based on the "02-custom-property-source" example project.

Main.java

public static void main(String[] args) {
    	// keep original section name
    	// testSection(false);
    	// strip section name
    	testSection(true);
    }
    
    private static void testSection(boolean stripKeys){
        Configuration cfg = ConfigurationProvider.getConfiguration().with(ConfigurationFunctions.section("example.", stripKeys));
        System.out.println("*****************************************************");
        System.out.println("stripKeys: " + stripKeys);
        System.out.println("*****************************************************");
        dump(cfg.getProperties(), System.out);
        System.out.println();
        System.out.println("Example Metadata:");
        System.out.println("\texample.type         :  " + cfg.get("example.type"));
        System.out.println("\texample.example.type :  " + cfg.get("example.example.type"));
        System.out.println("\ttype                 :  " + cfg.get("type"));
        dump(cfg.getProperties(), System.out);
    }

    private static void dump(Map<String, String> properties, PrintStream stream) {
        stream.println("FULL DUMP:");
        for (Map.Entry<String, String> en : new TreeMap<>(properties).entrySet()) {
            stream.println(format("\t%s = %s", en.getKey(), en.getValue()));
        }
    }

This is the result of the execution :

*****************************************************
stripKeys: true
*****************************************************
FULL DUMP:
	author = [e-mail]
	description = A minimal example using an self written property source.
	name = simple-propertysource
	type = standalone
	version = 1

Example Metadata:
	example.type         :  null
	example.example.type :  standalone
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -4
	at java.lang.String.substring(String.java:1931)
	at org.apache.tamaya.functions.ConfigurationFunctions$5$2.mapKey(ConfigurationFunctions.java:235)
	at org.apache.tamaya.functions.MappedConfiguration.get(MappedConfiguration.java:79)
	at org.apache.tamaya.functions.MappedConfiguration.get(MappedConfiguration.java:74)
	at org.apache.tamaya.functions.MappedConfiguration.get(MappedConfiguration.java:51)
	at org.apache.tamaya.examples.custompropertysource.Main.testSection(Main.java:84)
	at org.apache.tamaya.examples.custompropertysource.Main.main(Main.java:71)

In the dump of the MappedConfiguration, the "standalone" value is associated to the "type" key".
When calling the get method of the MappedConfiguration, the "standalone" value is got by prepending twice the "example." section name in the "type" key.
Without adding the section name, a NullPointerException is thrown.