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| import java.util.Map; | |
| import java.util.Random; | |
| import java.util.WeakHashMap; | |
| /** | |
| * @author skel | |
| */ | |
| public class WeakHashMapExample1 { | |
| private static final Map<String, Entry> map = new WeakHashMap<>(); | |
| private static final Random R = new Random(); | |
| private static final String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; | |
| private static void put(String value) { | |
| map.put(value, new Entry(value)); | |
| } | |
| public static void main(String[] args) { | |
| for (int i = 0; i <= 100_000_000; i++) { | |
| if (i % 10_000_000 == 0) { | |
| long freeMemoryMb = Runtime.getRuntime().freeMemory() / (1L << 20); | |
| long totalMemoryMb = Runtime.getRuntime().totalMemory() / (1L << 20); | |
| System.out.printf("Free memory: %dM / %dM\n", freeMemoryMb, totalMemoryMb); | |
| } | |
| put(nextString(10)); | |
| } | |
| System.out.println(map.size()); | |
| } | |
| private static String nextString(int length) { | |
| StringBuilder sb = new StringBuilder(length); | |
| for (int i = 0; i < length; i++) { | |
| sb.append(ALPHABET.charAt(R.nextInt(ALPHABET.length()))); | |
| } | |
| return sb.toString(); | |
| } | |
| public static class Entry { | |
| private final String value; | |
| public Entry(String value) { | |
| this.value = value; | |
| } | |
| } | |
| } |
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