ListTestingpublic class ListTesting extends Object
| Fields Summary |
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| public static final int | CAPACITY |
| Methods Summary |
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| public static void | main(java.lang.String[] args)
//In order to isolate the effects of synchronization, we make sure
//that the garbage collector doesn't interfere with the test. So
//we use a bunch of pre-allocated, pre-sized collections, and
//populate those collections with pre-existing objects. No objects
//will be created or released during the timing phase of the tests.
List[] l = {new Vector(CAPACITY), new Vector(CAPACITY),
new Vector(CAPACITY), new ArrayList(CAPACITY),
new ArrayList(CAPACITY), new ArrayList(CAPACITY),
Collections.synchronizedList(new ArrayList(CAPACITY)),
Collections.synchronizedList(new ArrayList(CAPACITY)),
Collections.synchronizedList(new ArrayList(CAPACITY))};
int REPEAT = (args.length > 0) ? Integer.parseInt(args[0]) : 100;
//Vary the order.
test(l[0], REPEAT, "Vector");
test(l[6], REPEAT, "sync ArrayList" );
test(l[3], REPEAT, "ArrayList");
test(l[1], REPEAT, "Vector");
test(l[4], REPEAT, "ArrayList");
test(l[7], REPEAT, "sync ArrayList" );
test(l[2], REPEAT, "Vector");
test(l[5], REPEAT, "ArrayList");
test(l[8], REPEAT, "sync ArrayList" );
| | public static void | test(java.util.List l, int REPEAT, java.lang.String ltype)
//need to initialize for set() to work. Don't measure this time
for (int j = 0; j < CAPACITY; j++)
l.add(Boolean.FALSE);
long time = System.currentTimeMillis();
//The test sets elements repeatedly. The set methods are
//very similar. Apart from synchronization, the Vector.set()
//is slightly more efficient than the ArrayList.set(), which
//is in turn more efficient than the wrapped ArrayList because
//there is one extra layer of method calls for the wrapped object.
for (int i = REPEAT; i > 0; i--)
for (int j = 0; j < CAPACITY; j++)
l.set(j, Boolean.TRUE);
System.out.println(ltype + " took " +
(System.currentTimeMillis()-time));
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