Question

how I can read a file in servlet which is outside of servlet container ?

Answer 1

In my job i have used the system property values to read the properties file outside the servlet container or WEB-INF folder or outside application context.

If you are using JBOSS server then use the

System.getProperty("jboss.server.home.dir");

or for Tomcat

System.getProperty("catalina.home");

Along with the above code , use the System.getProperty("file.separator");

This way you can read the updated changes from the file and prevent redeployement of war or jar file and works in all platforms(windows,unix).

if you are running a standalone application, u can supply your own property like below
during application launch

java -Dconfig.url="D:/Apps/"
String prop = System.getProperty("config.url");