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I'm running a simple Java program with below directory structure:
MyProject (A project in my Eclipse IDE)
'-- src
'-- Hello.java
In Hello.java I'm printing the value of 'user.dir' System property.
System.out.println(System.getProperty("user.dir"));
Compiled file for my class is getting stored in MyProject\bin folder.
When I'm running this class from Eclipse (Right click on source file and click on Run As->Java Application), it prints the path up to 'MyProject' folder, i.e. D:\Projects\Workspace\MyProject in console window.
Then I used the command window to run the same program. This is what I typed on window:
D:\Projects\Workspace\MyProject\bin>java Hello
and output on console is: D:\Projects\Workspace\MyProject\bin
bin has been added to previous value for user.dir.
Further, to check more, I this time executed the Java command from a different folder on command window:
D:\Projects\Workspace\MyProject>java -classpath D:\Projects\Workspace\MyProject\bin Hello
This time output on command window is: D:\Projects\Workspace\MyProject
This value changes when I changed the folder on command window, and when I'm running the program from Eclipse, the value for user.dir is the project folder. So I would like to understand, what is the basis for deriving the value of 'user.dir'? How does JVM decides, what should be the value for user.dir?
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It's the directory where java was run from, where you started the JVM. Does not have to be within the user's home directory. It can be anywhere where the user has permission to run java. So if you cd into /somedir , then run your program, user.
This directory is named by the system property user. dir, and is typically the directory in which the Java virtual machine was invoked. In other words, user. dir is the working directory of the process that started the Java process at the time when it started the process.
System properties include information about the current user, the current version of the Java runtime, and the character used to separate components of a file path name. The following table describes some of the most important system properties.
properties file located in users->appdata->locallow->sun->java>deployment and also directly putting key=value in runtime parameter in java control panel but not working. Edit: We use jeety server for deployment. And we have many properties file bundled with our souce code. What kind of application is it?
As defined by java.lang.System specification the user.dir property returns the current working directory (i.e. the current directory when JVM was started):
user.dirUser's current working directory
I see nothing contradictory in your example. The only thing unclear here is the name of the property. I don't understand why they chose to put 'user' in there.
Similarly if you executed the same Java program from totally different path you would get the other path as the outcome. Try this yourself:
c:
cd c:\
java -cp D:\Projects\Workspace\MyProject\bin Hello
What Eclipse does before running your program is something similar to:
d:
cd d:\projects\workspace\myproject
java -cp d:\projects\workspace\myproject\bin Hello
The property user.dir is defined to be the current working directory. The javadoc for System details the various different system properties.
Maybe you actually want user.home?
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