java语言的科学与艺术-编程练习7.4

import java.lang.Runtime;
import acm.program.*;
public class GCTest extends ConsoleProgram {
    public void run() {
        Runtime myRuntime = Runtime.getRuntime();
        long oldMemory = myRuntime.freeMemory();
        for(int i = 0; i < 10000; i++){
            new Rational(1);
        }
        myRuntime.gc();
        long newMemory = myRuntime.freeMemory();
        long freeMemory = newMemory - oldMemory;
        println("Allocating 10000 Rational objects");
        println("Garbage collections freed " + freeMemory + " bytes");
    }
}