Cannot import Map.Entry

Question

I have problems with import Map.Entry. Even though I have import import java.util.Map.Entry - there is an error : "The import java.util.Map.Entry cannot be resolved". And entrySet() method doesnot work. what is the problem? (I use jre8)

import java.io.File;
import java.util.LinkedHashMap;
import java.util.Map;

import java.util.Set;

import org.biojava3.core.sequence.ProteinSequence;
import org.biojava3.core.sequence.io.FastaReaderHelper;




public class Main {

/**
 * @param args
 */
public static void main(String[] args) throws Exception {
    LinkedHashMap<String, ProteinSequence> a = FastaReaderHelper.readFastaProteinSequence(new File("A2RTH4.fasta"));

    for (Map.Entry<String, ProteinSequence> entry : a.entrySet(); //entrySet A map entry (key-value pair). 
    {
        System.out.println( entry.getValue().getOriginalHeader() + "=" + entry.getValue().getSequenceAsString() );
    }
    }

}

"And entrySet() method does not work" - in what way? Please be more precise. Also, please provide a short but complete example demonstrating the problem. It works fine for me... — Jon Skeet, Jun 24 '14 at 11:03
Tried to reproduce, but `import java.util.Map.Entry` lets me declare an instance of `Entry` without problems. Could you show us some code? — S.L. Barth is on codidact.com, Jun 24 '14 at 11:10
Just copied your code and made a few mocks for ProteinSequence etc. The only error I got is that there is a ")" missing in your `for` loop. The semicolon (";") should be a ")". Does the problem remain when you do that? — S.L. Barth is on codidact.com, Jun 24 '14 at 11:28
Yes still it remains, do u thing it might be a problem with eclipse installation or JRE system library? — Ewa Kania, Jun 24 '14 at 11:33
Is it say something more ?Multiple markers at this line - The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files — Ewa Kania, Jun 24 '14 at 11:44
Are you using Eclipse? Then it’s [this issue](http://stackoverflow.com/a/26105217/2711488) — Holger, Dec 08 '14 at 20:17

score 5 · Answer 1 · answered Jun 24 '14 at 11:09

5

for(Map.Entry<String, Integer> entry : someMap.entrySet())

works with import java.util.Map import alone.

answered Jun 24 '14 at 11:09

Nikhil Talreja

2,754
1
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user840718 · Answer 2 · 2014-06-24T13:00:39.760

0

import java.util.Map is enough

Try this code, should be work:

public static void main(String[] args) throws Exception {
LinkedHashMap<String, ProteinSequence> a = FastaReaderHelper.readFastaProteinSequence(new File("A2RTH4.fasta"));
Set entrySet = a.entrySet();
Iterator it = entrySet.iterator();
// Iterate through LinkedHashMap entries
System.out.println("LinkedHashMap entries : ");
while(it.hasNext())
  System.out.println(it.next());
  }
}

Instead of foreach, try an Iterator to iterate over a LinkedHashMap data structure.

edited Jun 24 '14 at 13:00

answered Jun 24 '14 at 11:05

user840718

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6
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1

even if i have import java.util.Map i have problem with my code line for (Map.Entry entry : a.entrySet(); eclipse says : reference to the missing element 'Map.Entry' – Ewa Kania Jun 24 '14 at 11:13
Maybe you have to set Eclipse correctly, but posting code will be the better solution for help. – user840718 Jun 24 '14 at 11:16
There is a syntax error, close parenthesis out the for cycle. – user840718 Jun 24 '14 at 11:34
thats true, but it s not the main problem. still it s wrong something with the reference to Map.Entry – Ewa Kania Jun 24 '14 at 11:38

score 0 · Answer 3 · answered Jun 24 '14 at 11:29

0

for (Map.Entry<String, ProteinSequence> entry : a.entrySet();

should be

for (Map.Entry<String, ProteinSequence> entry : a.entrySet())

(closing parenthesis instead of semicolon).

answered Jun 24 '14 at 11:29

Ian Roberts

120,891
16
170
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Cannot import Map.Entry

3 Answers3