Skip to content

Fix NPE in MDCContextMap #430

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Oct 6, 2020
Merged

Fix NPE in MDCContextMap #430

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
0533917
Fix NPE in MDCContextMap
SiegfriedTobias1 Oct 5, 2020
cd4f02c
Add test for MDC NPE fix
SiegfriedTobias1 Oct 5, 2020
544e57c
Add more tests for MDC NPE fix
SiegfriedTobias1 Oct 6, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions log4j-to-slf4j/src/main/java/org/apache/logging/slf4j/MDCContextMap.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,7 +71,8 @@ public void clear() {

@Override
public boolean containsKey(final String key) {
return MDC.getCopyOfContextMap().containsKey(key);
Map<String, String> map = MDC.getCopyOfContextMap();
return map != null && map.containsKey(key);
}

@Override
Expand All @@ -88,7 +89,8 @@ public Map<String, String> getImmutableMapOrNull() {

@Override
public boolean isEmpty() {
return MDC.getCopyOfContextMap().isEmpty();
Map<String, String> map = MDC.getCopyOfContextMap();
return map == null || map.isEmpty();
}

@Override
Expand Down
41 changes: 40 additions & 1 deletion log4j-to-slf4j/src/test/java/org/apache/logging/slf4j/LoggerTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@
import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;
import org.slf4j.MDC;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;
Expand Down Expand Up @@ -165,5 +166,43 @@ public void mdc() {
assertThat(list.strList, hasSize(2));
assertTrue("Incorrect year", list.strList.get(0).startsWith("2010"));
}
}

@Test
public void mdcNullBackedIsEmpty() {
assertNull("Setup wrong", MDC.getCopyOfContextMap());
assertTrue(ThreadContext.isEmpty());
}

@Test
public void mdcNullBackedContainsKey() {
assertNull("Setup wrong", MDC.getCopyOfContextMap());
assertFalse(ThreadContext.containsKey("something"));
}
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I would separate these into two tests, one for each API.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

An edge case worth testing IMO is getting a null key.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thank you for the feedback! I split the tests and added some tests concerning null keys.


@Test
public void mdcNullBackedContainsNullKey() {
assertNull("Setup wrong", MDC.getCopyOfContextMap());
assertFalse(ThreadContext.containsKey(null));
}

@Test
public void mdcContainsNullKey() {
try {
ThreadContext.put("some", "thing");
assertNotNull("Setup wrong", MDC.getCopyOfContextMap());
assertFalse(ThreadContext.containsKey(null));
} finally {
ThreadContext.clearMap();
}
}

@Test
public void mdcCannotContainNullKey() {
try {
ThreadContext.put(null, "something");
fail("should throw");
} catch (IllegalArgumentException | NullPointerException e) {
// expected
}
}
}