Setting environment variable and accessing it in Java program on Azure webapp

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Sometimes, you want to set new environment variable and want to access it in your Java Program.

You can do this by setting up the value in JAVA_OPTS either in web.config or in webapps App Setting.

1. In web.config -

<httpPlatform processPath="%AZURE_TOMCAT7_HOME%\bin\startup.bat" arguments="">
<environmentVariables>
<environmentVariable name="JAVA_OPTS" value="-DmyNewEnvVar=Wow" />
</environmentVariables>
</httpPlatform >

 

2. In App Setting -

Note: Make sure you set the "-D" text before your variable name.

Once you add the environment variable as mentioned above, you can access it in code using the System class in Java program.

System.getProperty("myNewEnvVar");

 

To list multiple variables use can delimit it by a space " ". For eg.  -DmyNewEnvVar=Wow -DmyAnotherEnvVar=Wowa

 

If you want to list all the available environment variable you can use the getProperties() method call.

Note: The web.config setting will override the app_setting way.

 

Also, if you want to access the existing environment variable, you can use the "-D" way to set the value in the web.config.

For eg, you want to use the %HTTP_PLATFORM_PORT% value, you can set

JAVA_OPTS="-Dhttp.port=%HTTP_PLATFORM_PORT%"

Now, using the System.getProperty("http.port"), you can access the port value for the platform.