Logger class is not serializable

[makkimesser]

Description

Since 2.21.0 serializing a Logger raises java.io.NotSerializableException.

Maybe this is caused by this commit (see my comment on commit): e86d28b

Configuration

Version: 2.21.0

Operating system: Windows-10

JDK: OpenJDK 1.8.0_382

Logs

Exception in thread "main" java.io.NotSerializableException: java.lang.ThreadLocal
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
	at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
	at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
	at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
	at test.TestSerializeLogger.main(TestSerializeLogger.java:14)

Reproduction

package test;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

@SuppressWarnings("javadoc")
public class TestSerializeLogger {
	public static void main(final String... args) throws IOException {
		try (ObjectOutputStream objOut = new ObjectOutputStream(new ByteArrayOutputStream())) {
			Logger logger = LogManager.getLogger("Test");
			objOut.writeObject(logger);
		}
	}
}

[jvz]

Alright, I've converted that test into a JUnit one here:

    @Test
    void canSerializeRoundTrip() throws IOException {
        final ReusableMessageFactory factory = new ReusableMessageFactory();
        final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        try (final ObjectOutputStream out = new ObjectOutputStream(bytes)) {
            out.writeObject(factory);
        }
        try (final ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(bytes.toByteArray()))) {
            assertDoesNotThrow(in::readObject);
        }
    }

Should be simple enough to fix!

[vy]

@makkimesser, could you share some details about your use case, please? Why do you serialize Loggers?