[Solved] if ( l

Question

You’re calling A.get(). That returns a java.lang.Object. You’re trying to access the key attribute f this object. But there is no attribute key in the class Object. Hence the error.

You’re probaly using raw types, i.e. using a List instead of a List<MyClassWhichHasAKeyAttribute>. Don’t use raw types.

There are several other potential explanations, but since you won’t post your code, this is the best guess we can make.

The other errors come from not importing a class, or from calling methods that don’t exist. Read the javadoc.

Accepted Answer

You’re calling A.get(). That returns a java.lang.Object. You’re trying to access the key attribute f this object. But there is no attribute key in the class Object. Hence the error.

You’re probaly using raw types, i.e. using a List instead of a List<MyClassWhichHasAKeyAttribute>. Don’t use raw types.

There are several other potential explanations, but since you won’t post your code, this is the best guess we can make.

The other errors come from not importing a class, or from calling methods that don’t exist. Read the javadoc.