Java System Properties
Quick Reference Guide Java System Property

The Java System Property accepts a boolean value (true or false)

Default Value

false Overview

When set to true Java networking classes ( will attempt to use proxies defined by the operating system.

This property is supported on Windows, Mac OSX and on Linux when configured through Gnome 2.x.

The property is only checked once during startup.

Related System Properties

Here are some other networking Java system properties:

Supported Since

Java has supported the system property since at least version 8, support may go back to even older versions of java.

Setting on Startup

You can set the java system property during startup of the java runtime using the -D command line argument:

java MyAppMain

You may also be able to specify via the JAVA_TOOL_OPTIONS environment variable:

Setting / Reading at Runtime

You can set at runtime with the following Java code:

System.setProperty("", "true");

WARNING: Depending on the property and JVM version using setProperty may or may not work if the JDK Java class that uses this variable has already been loaded. The value of the system property may be cached within an internal private static variable of the implementing class.

To read the value of at runtime, you can use this Java code:

String propertyValue = System.getProperty("");
if (propertyValue != null) {
    System.out.println(" = " + propertyValue);
} else {
    System.out.println(" was null");