Sonar Error - Make this member "protected"

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In the below class I am declaring myMap

public class AllMap {
    public static final Map<String, String> myMap= new HashMap<>();
    static {
        Map.put("yy", "AA");
        Map.put("xx", "BB");
    }
}

I need to access map in other class.

public class Test {
    FieldMap.Map;
}

Everything is working fine,but sonar is giving warning on 1st class:

Make this member "protected".

on the line

public static final Map<String, String> myMap = new HashMap<>();

Should I ignore this warning or should I change it to protected?

sonarqube protected java
3 Answers

If you need to access the map in other classes, then you should protect it against modifications:

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class AllMap {
    public static final Map<String, String> myMap;
    static {
        final Map<String, String> tmpMap = new HashMap<>();
        tmpMap.put("yy", "AA");
        tmpMap.put("xx", "BB");
        myMap = Collections.unmodifiableMap(tmpMap);
    }
}

You can still use it and SonarQube won't mark this as error (because the map is read-only).

Read more about Collections#unmodifiableMap(Map).

user_49448470

Sonar is giving you suggestion that your "member" which is:

public final Map<String, String> myMap = new HashMap<>();

should not be public.

Why?

Leaving this as public makes it available from any other package - so you are exposing the member to everybody. Below code is accessing the member directly:

AllMap allMap = new AllMap();
allMap.myMap.put("X", "Y");

In most cases members should be private and accessed by getters and setters, which could prevent with returning the same reference - so you can implement some logic before you get the reference or set it.

If you need to make it static, make static getters and setters.

user_52940160

Sonar lint issue because you are exposing references to mutable objects to client code.Here you are exposing a Map though it is final the final object allows clients to modify the contents of the object.

Never initialize such a field to a client-provided object reference or return the object reference from an accessor.

private static final SomeType [] THE_THINGS = { ... };
public static final List<SomeType> SOMETHINGS =
  Collections.unmodifiableList(Arrays.asList(THE_THINGS));

Reference link

Reference link2

user_79983190
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