In JDK 1.4:
```java
Map map = new HashMap();
Iterator it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
}
```
In JDK 1.5, using the new feature: the For-Each loop:
```java
Map map = new HashMap();
for (Map.Entry entry : map.entrySet()) {
Object key = entry.getKey();
Object value = entry.getValue();
}
```
The for-each loop simplifies the iteration over the collection and improves code readability.