Java: Generic Type type mismatch syntax error

Question

I have this declaration/initiation written for Java JDK 1.6

Map<String, <? extends List<?>>> groupThemTogether = new HashMap<String, ArrayList<String[]>>();

The error happens at the first comma. The error message is

Type mismatch: cannot convert from HashMap<String,ArrayList<String[]>> to Map<String,List>

Why doesn't this compile?

Oops, this compiled for me (removed previous post as I copied the wrong code) Map<String, ? extends List<?>> groupThemTogether = new HashMap<String, ArrayList<String[]>>();. — Buhake Sindi
– Buhake Sindi, Commented Jul 14, 2011 at 5:42

Bohemian · Accepted Answer · 2011-07-14 05:11:22Z

3

You've got too many angle brackets. Try this:

Map<String, ? extends List<?>> groupThemTogether = new HashMap<String, ArrayList<String[]>>();

This compiles for me.

answered Jul 14, 2011 at 5:11

Bohemian♦

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Comments

Daniel Lundmark · Accepted Answer · 2011-07-14 05:10:26Z

0

Are you sure of this?

This, similar code, compiles OK for me:

Map<String, ? extends List<?>> groupThemTogether = new HashMap<String, ArrayList<String[]>>();

answered Jul 14, 2011 at 5:10

Daniel Lundmark

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