You can find out the value of a system property if you set it programmatically. You cannot find out the value of a system property if you set it in the derby.properties file.
Properties sprops = System.getProperties(); System.out.println("derby.storage.pageSize value: " + sprops.getProperty("derby.storage.pageSize"));
You can also use Java Management Extensions (JMX) technology to obtain system information, including some settings that correspond to system properties. For details, see "Using Java Management Extensions (JMX) technology" in the Derby Server and Administration Guide.