Java: dynamic properties

Question

Ladies & Gentlemen,

I´m new to Java, forgive me if it´s obvious, but I haven´t found much about it.

I´d like to create dynamic properties (variables) for

Answer 1

Java doesn't support it. Your best bet is to store/manage in some external datastore which you can access from inside the Java code. As a basic and builtin example, you can make use of java.util.Properties API which you load on every request, or cache and reload at timed intervals, or reload programmatically. You can then store the key-value pairs in a .properties file which you just place in the classpath. Here is a Sun tutorial about the subject.

A properties file can look like

key1=value1
key2=value2
key3=value3

If you put it in the classpath, then you can load it as

Properties properties = new Properties();
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
properties.load(classLoader.getResourceAsStream("file.properties"));
String key1 = properties.getProperty("key1"); // value1

Other alternatives are for example XML files (which you can access using any Java XML API) or just a database (which you can access using JDBC API).