Get the Java Project root directory

Acquisition of relative paths

Description: The relative path (that is, who does not specify when it is relative) can be obtained in the following ways (whether it is a generic Java project or a Web project)

String Path = System.getproperty ("User.dir");

E:\github\J2SE

In the relative path above, the files in the Java project are relative to the project's root directory
File paths in Web projects vary depending on the Web server (tomcat is relative to the Tomcat installation directory \ Bin)

The acquisition of a class-loaded directory (that is, when a class of runtime obtains its mount directory)
Common method One (whether it is a generic Java project or a Web project, first navigate to the first level directory where you can see the package path)

String path = GetClass (). getClassLoader (). GetResource ("Logback.xml"). GetPath ();

/e:/github/j2se/target/classes/logback.xml

General Method Two
String path = GetClass (). GetResource ("/logback.xml"). GetPath ();

/e:/github/j2se/target/classes/logback.xml

This method must start with '/'

Access to the Web project root (after publishing)

Request.getrealpath ("/") This method has not been recommended, presumably we have noticed in the process of use.

It is replaced by the following:

String path = Request.getsession (). Getservletcontext (). Getrealpath ("/upload");

E:\Apache-tomcat\apache-tomcat-7.0.53\wtpwebapps\Struts2\upload

String path = Request.getsession (). Getservletcontext (). Getrealpath ("");

E:\Apache-tomcat\apache-tomcat-7.0.53\wtpwebapps\Struts2

Here we have to pay attention to a detail, in which the final path is in the appended state if the new path is placed in the parameter.

Get the Java Project root directory