问题
I've been trying to use the indexed notation used for getProperty of PropertyUtils to retrieve an element in a list contained as a map value. Here's an example (I'm using a general syntax here):
map = {"aList": ["elem1", "elem2", "elem3"]}
Let say, I want to get the value "elem2", I'm trying to do it using:
PropertyUtils.getProperty(map, "aList[1]");
but it doesn't seem to work. I always get a null value. Is there another way to do this. To be clear, I know I can do a getProperty("aList").get(0) (after explicitly casting, of course) but I'm working on a solution that needs the code stated above to work.
回答1:
Ok, so I figured it out. The code below works like how I wanted:
PropertyUtils.getProperty(map, "(aList)[1]");
I think, based on this documentation, what I'm doing here is that I'm specifying that aList is a key and not an indexed property of the bean. Something like that.
来源：https://stackoverflow.com/questions/10738019/how-to-use-propertyutils-to-get-an-element-from-a-list-inside-a-map