Why does getHeaderField() return a String where as getHeaderFields() return Map<String,List<String>> in HttpUrlConnection

Question

I am using HttpUrlConnection in my android code and I am trying to access header fields post getResponseCode() call. For a single header method is -

public String getHeaderField(String name)

where as to get all headers it is -

public Map<String,List<String>> getHeaderFields()

So whats the deal here? Are we allowed to set headers multiple times?

Documentation of getHeaderField() method says -

If called on a connection that sets the same header multiple times with possibly different values, only the last value is returned.

So whats with getHeaderFields() method? I would appreciate if someone could give an example to help understand the difference.

Comparing with HttpResponse which has method -

Header[] getHeaders(String var1);

I would have expected method -

public List<String> getHeaderField(String name)

but that does not seem to be the case. So how do I handle this?

Answer 1

Headers (not sure if all of them) can have multiple values, and I don't know why the API was designed this way ( getHeaderField() returns the values separated by ; while getHeaderFields() returns a list of values, which is an inconsistent design choice in my opinion).

Well, to get a list of values for some header: getHeaderFields() method returns a map, so if you already know the header name, you don't need to iterate, just do getHeaderFields().get("headername") to get the list of values of that header.