java中的不同的value類型從map中獲取不同的value值

protected <V> V getValFromMap(Map<String, Object> headers, String name, Class<V> type) {
Object value = headers.get(name);
if (value == null) {
return null;
}
if (!type.isAssignableFrom(value.getClass())) {
if (logger.isWarnEnabled()) {
logger.warn("Skipping header '" + name + "'expected type [" + type + "], but got [" +
value.getClass() + "]");
}
return null;
}
else {
return type.cast(value);
}
}