Cannot find symbol when using entrySet() function after import java.util.*

java import hashmap entryset
Stif Spear Subba picture Stif Spear Subba · Oct 15, 2017 · Viewed 10.4k times · Source

I am using a function Map.entrySet(). When I am using import java.util.* it gives cannot find symbol error. But, when I am doing import java.util.Map.Entry it compiles. Shouldn't "*" include Map.Entry?

Am I missing anything?

Bottom line using import java.util.* gives me cannot find symbol error. For the same code import java.Map.Entry; does not. Why?

Thank You.

Answer

Aleh Maksimovich picture Aleh Maksimovich · Oct 15, 2017

The star import is used for importing all classes of the package. When you specify

import java.util.*;

You are denoting that all classes that have full name java.util.<ClassName> are to be considered imported.

java.util.Map.Entry is an inner class of java.util.Map class. The star import for sub-classes will be something like this

import java.util.Map.*;

I can't say that it is a good practice to use start imports at all. Most of coding guidelines recommend to avoid it. Sub-class star imports isn't something you usually will come across in the code.

Related questions

Eclipse error: "The import XXX cannot be resolved"

I'm trying to work with Hibernate in Eclipse. I'm creating a new simple project and I've downloaded a collegue project too, via CVS. Both don't work, while on my collegue's Eclipse do. The problem is that, for each import of …

Read More
Importing JSON into an Eclipse project

I'm an aspiring Java programmer looking to use JSON in a project. I was following a programming tutorial (from a book) which asked me to import JSON into my project by using the following line: import com.google.appengine.repackaged.…

Read More
Extend a java class from one file in another java file

How can I include one java file into another java file? For example: If I have 2 java file one is called Person.java and one is called Student.java. How can I include Person.java into Student.java so that …

Read More