This works a treat. Requires Java 7, Apache commons logging, Apache commons lang (v2.6) and Apache commons Configuration:
package corejava.reloadTest;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy;
public class MyApplicationProperties {
private static PropertiesConfiguration configuration = null;
static {
try {
configuration = new PropertiesConfiguration("test.properties");
} catch (ConfigurationException e) {
e.printStackTrace();
}
configuration.setReloadingStrategy(new FileChangedReloadingStrategy());
}
public static synchronized String getProperty(final String key) {
return (String) configuration.getProperty(key);
}
}
and test it with:
package corejava.reloadTest;
public class TestReloading {
public static void main(String[] args) {
while (true) {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(MyApplicationProperties.getProperty("key"));
}
}
}
Output when you change test.properties is something like this (original contents of test.props was key=value, later changed to key=value1 mid-program execution):
value
value
value
value
value
Jan 17, 2015 2:05:26 PM org.apache.commons.configuration.PropertiesConfiguration reload
INFO: Reloading configuration. URL is file:/D:/tools/workspace /AutoReloadConfigUsingApacheCommons/resources/test.properties
value1
value1
value1
You could also consider Official Spring Framework Reference Documentation Refreshable beans , using a DSL like Groovy for this.