JAVA map的遍历

第一种entrySet，效率较高,推荐用这种:

Map<String, Object> parameters = new HashMap<String, Object>();
parameters.put(&quot;...&quot;,&quot;...&quot;);
...
Iterator iter = parameters.entrySet().iterator();
while (iter.hasNext()) {
	Map.Entry<String, Object> entry = (Map.Entry<String, Object>) iter.next();
	Object key = entry.getKey();
        Object value = entry.getValue();
}

第二种keySet，效率较低：

Map<String, Object> parameters = new HashMap<String, Object>();
parameters.put(&quot;...&quot;,&quot;...&quot;);
...
Iterator iter = parameters.keySet().iterator();
while (iter.hasNext()) {
Object key = iter.next();
Object val = map.get(key);
}