Cannot load properties from jar

Question

I have small app and I tested and packed to jar and am trying to run it but I have error.

Here is my project structure:

src
  -kie.template
  ----- ServerMain.java   ==> Class with main
  -kie.template.util
  ---- PropUtils.java
  ---- server.properties
target
  -kietemplate.jar
  ---- lib

In the main method, PropUtils class reads properties.

public class PropUtils {

    private static final String PROPERTIES = "server.properties";

    public static Properties load() {
    Properties properties = new Properties();
            InputStream is = null;
            try {
                properties.load(PropUtils.class.getResourceAsStream(PROPERTIES));

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (is!=null) try{is.close();}catch(IOException e){}
            }

            return properties;
        }
     }
}

When I run the ServerMain class directly, it works fine. But after I packed it to jar and run, it shows error:

java -cp lib -jar kietemplate.jar

Caused by: java.lang.NullPointerException
    at java.util.Properties$LineReader.readLine(Properties.java:418)
    at java.util.Properties.load0(Properties.java:337)
    at java.util.Properties.load(Properties.java:325)
    at au.org.jeenee.kie.template.util.PropUtils.load(PropUtils.java:26)

The properties file is in the directory when I look into the jar file. jar tf kietemplate.jar

Any help would be appreciated very much.

EDIT: I changed the logic to read properties:

Properties properties = new Properties();
InputStream is = null;
try {
    File file = new File("server.properties");
    is = new FileInputStream(file);
    properties.load(new InputStreamReader(is));
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (is!=null) try{is.close();}catch(IOException e){}
}

It requires the properties file in parent directory of the jar file.

Answer 1

Your code works fine on my computer, both from the JAR and the filesystem.

A possible cause for that behaviour is the filesystem being case insensitive, but the jar file being case sensitive. But we really can't tell from the source code alone.