getParameterMap()的返回值为Map<String, String[]>，从其中取得请求参数转为Map<String, String>的方法如下：

直接遍历报错：[Ljava.lang.String;@44739f3f

Map<String, String> tempMap = new HashMap<String, String>();
Map<String, String[]> reqMap = req.getParameterMap();
Set<Entry<String, String[]>> set = reqMap.entrySet();
Iterator<Entry<String, String[]>> it = set.iterator();
while (it.hasNext()) {
Entry<String, String[]> entry = it.next();

System.out.println("KEY:"+entry.getKey());
for (String str : entry.getValue()) {
System.out.println(str);
tempMap.put(entry.getKey(), str);
}
}

顺便写一下Map的遍历：

Set<Map.Entry<String, String>> itermap = resMap.entrySet();
for (Map.Entry<String, String> entry : itermap) {
String key = entry.getKey();
String value = entry.getValue();
System.out.println(key + ": " + value);

}