Java: Cannot find symbol error on Map, HashMap

Question

I'm trying to run this code:

import java.util.*;

public class ScanReg {
  public Map<Integer, ArrayList<Long>> scanMap = new HashMap<Integer, ArrayList<Long>>();
}

within this class:

import java.util.*;

public class NxtStart {
  ScanReg sr = new ScanReg();
}

This keeps giving me the following error:

.\ScanReg.java:6: error: cannot find symbol
        public Map<Integer, ArrayList<Long>> scanMap = new HashMap<Integer, Arra
yList<Long>>();
               ^
  symbol:   class Map
  location: class ScanReg
.\ScanReg.java:6: error: cannot find symbol
        public Map<Integer, ArrayList<Long>> scanMap = new HashMap<Integer, Arra
yList<Long>>();
                                                           ^
  symbol:   class HashMap
  location: class ScanReg
2 errors

Can somebody please tell me why?

You don't have your own local package named `java.util` do you? I would try to import the whole class name: `import java.util.Map;` and same for the other util classes used such as HashMap. — Hovercraft Full Of Eels, Oct 23 '11 at 01:23
I cannot recreate this based on the info in the question. Something else is going on. And since the OP most likely doesn't care anymore, it should be closed as "not reproducible". — Stephen C, Aug 27 '21 at 08:13

score 2 · Answer 1 · answered Oct 23 '11 at 01:36

2

You're possibly compiling using Java 1.4 and using generics ( only available from 1.5 onwards ).

answered Oct 23 '11 at 01:36

Kal

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65
65

1

Sorry .. I cannot reproduce the problem. I copied your ScanReg.java and it compiled fine. – Kal Oct 23 '11 at 01:39

score -2 · Answer 2 · answered May 23 '19 at 03:18

-2

You need to declare your inner class as static

public static class ScanReg {}

Else, put in different java file and import ScanReg.

answered May 23 '19 at 03:18

Edward Aung

3,014
1
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This won't solve the problem he was trying to solve. It was about library classes and imports. Also, note that this is an **ancient** question. If the OP hasn't solved the problem by now, he will no longer care. – Stephen C May 23 '19 at 03:23
I recreated the problem and test this to be working solution – Edward Aung Aug 27 '21 at 07:35
Well I >could not< recreate the problem. When I compile those two files from the command line (Java 8). I don't get any compilation errors. There was something "funky" that the OP was not telling us. – Stephen C Aug 27 '21 at 08:11

Java: Cannot find symbol error on Map, HashMap

2 Answers2