在Jboss Fuse / Karaf中从文件系统加载属性文件会抛出Nullpointer

Question

I try to load a property file in Java running on JBossFuse/karaf.

The file is located at $[karaf.home]/etc/bean.properties

The Code is able to load properties inside the bundle fine, but now I try to exclude the properties from the project itself and the code throws a Nullpointer-Exception.

The Path is properly resolved on my development machine as

C:\\Users\\someone\\devstudio\\runtimes\\jboss-fuse-6.3.0.redhat-135\\etc\\bean.properties

The property-File can be loaded in the blueprint-XML to configure beans, but to access the bean my code needs the CamelContext. As I have some static codeblocks that are accessed without an exchange/context/registry, I also wanted to be able to load the properties in Java.

Both the functions throw the NullPointerException and I guess, it is because the code runs in Fuse.

public static Properties getProperties(String location) {
    Properties prop = new Properties();
    InputStream input = null;

    try {
        input = PropertyLoader.class.getClassLoader().getResourceAsStream(location);
        prop.load(input);
    } catch (IOException ex) {
        log.error("Error loading properties file from: " + location, ex);
        return null;
    } finally {
        if (input != null) {
            try {
                input.close();
            } catch (IOException e) {
                log.error(e);
            }
        }
    }
    return prop;
}

public static Properties getPropertiesFromFilesystem(String location) {
    Properties prop = new Properties();
    InputStream input = null;

    try {
        input = new FileInputStream(location);
        prop.load(input);
    } catch (IOException ex) {
        log.error("Error loading properties file from: " + location, ex);
        return null;
    } finally {
        if (input != null) {
            try {
                input.close();
            } catch (IOException e) {
                log.error(e);
            }
        }
    }
    return prop;
}

The Exception:

java.lang.NullPointerException at java.util.Properties$LineReader.readLine(Properties.java:434)[:1.8.0_91] at java.util.Properties.load0(Properties.java:353)[:1.8.0_91] at java.util.Properties.load(Properties.java:341)[:1.8.0_91] at com.mycompany.util.PropertyLoader.getProperties(PropertyLoader.java:19)[319:camel-archetype-blueprint:0.0.14] at com.mycompany.camel.blueprint.MyProcessor.process(MyProcessor.java:21)[319:camel-archetype-blueprint:0.0.14] at org.apache.camel.processor.DelegateSyncProcessor.process(DelegateSyncProcessor.java:63)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.management.InstrumentationProcessor.process(InstrumentationProcessor.java:77)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.processor.RedeliveryErrorHandler.process(RedeliveryErrorHandler.java:468)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:196)[231:or g.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.processor.Pipeline.process(Pipeline.java:121)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.processor.Pipeline.process(Pipeline.java:83)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.processor.CamelInternalProcessor.process(CamelInternalProcessor.java:196)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.component.timer.TimerConsumer.sendTimerExchange(TimerConsumer.java:192)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at org.apache.camel.component.timer.TimerConsumer$1.run(TimerConsumer.java:76)[231:org.apache.camel.camel-core:2.17.0.redhat-630135] at java.util.TimerThread.mainLoop(Timer.java:555)[:1.8.0_91] at java.util.TimerThread.run(Timer.java:505)[:1.8.0_91]

Any help would be highly appreciated.

Answer 1

Do not do that. You are looking for trouble.

1. Load properties the OSGi way (use .cfg as extension and a blueprint property-placeholder bean)
   You have the added benefit of getting notified if the file changes (if you wish)
2. Inject them in a bean EVEN IF you are using only static methods.
   Don't mix managed beans with unmanaged static code unless you know very well what you are doing.

If some " static " code requires properties means that it is stateful , and this class deserves to be instantiated to a bean.

Answer 2

Not sure why you are getting an NPE without a more complete example. If you need to use properties without a route, you should be using Camel's property placeholder facilities:

https://access.redhat.com/documentation/en-us/red_hat_jboss_fuse/6.3/html/apache_camel_development_guide/basicprinciples#BasicPrinciples-PropPlaceholders