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javamemorywindows-7heap-memory

Java: Increasing heap size in Windows doesn't take effect

I run the following code from command line:

public class MemoryTest {

    public static void main(String[] args) {
        Runtime rt = Runtime.getRuntime();
        long maxMb = rt.maxMemory()/(1024*1024);
        System.out.println("Your JVM will use up to " + maxMb + " MB of memory for its heap");
    }

}

It outputs: 247 MB

I then go to the Java icon in the Control Panel -> Java tab -> View -> Runtime Parameters column. I enter the following: -Xms512M -Xmx1024M

Then I run the memory test again. Output: 247 MB.

Why doesn't it increase?

Solution

  • If you are running java from the command line, you need to specify it on the command line

    Try

    java -mx1g MemoryTest