Java Map遍历过程中删除元素

Map<String, String> testMap = Maps.newHashMap();for (int i = 0; i < 10; i++) {    testMap.put(String.valueOf(i), String.valueOf(i) + "$$$$");}Iterator<Map.Entry<String, String>> it = testMap.entrySet().iterator();while (it.hasNext()) {    Map.Entry<String, String> entry = it.next();    System.out.println(entry.getKey() + "=>" + entry.getValue());    it.remove();}System.out.println(testMap.size());