package collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Calendar;
public class HashMapTest {
public static void main(String[] args) {
HashMap hashmap = new HashMap();
for (int i = 0; i < 1000; i++) {
hashmap.put("" + i, "hello");
}
long bs = Calendar.getInstance().getTimeInMillis();
Iterator iterator = hashmap.keySet().iterator();
// String value = "";
while (iterator.hasNext()) {
// value = hashmap.get(iterator.next());
System.out.println(hashmap.get(iterator.next()));
}
System.out.println(Calendar.getInstance().getTimeInMillis() - bs);
listHashMap();
}
public static void listHashMap() {
java.util.HashMap hashmap = new java.util.HashMap();
for (int i = 0; i < 1000; i++) {
hashmap.put("" + i, "hello");
}
long bs = Calendar.getInstance().getTimeInMillis();
// Set set = hashmap.entrySet() ;
java.util.Iterator it = hashmap.entrySet().iterator();
while (it.hasNext()) {
java.util.Map.Entry entry = (java.util.Map.Entry) it.next();
// entry.getKey() 返回与此项对应的键
// entry.getValue() 返回与此项对应的值
System.out.println(entry.getValue());
}
System.out.println(Calendar.getInstance().getTimeInMillis() - bs);
}
}