[Maven-Runtime] Support slf4j.api version 2 in m2e.maven.runtime

As part of the new SLF4J-2 major version the mechanism to connect the
slf4j.api with a logging back-end has been changed from the
static-binding mechanism to Java's ServiceLoader mechanism [1].

In order to support slf4j.api-2 a provider for the maven-slf4j-provider
(the logging backend provided/used by Maven based on slf4j-simple) is
needed. Because maven-slf4j-provider does not provide it itself we have
to supply it for m2e.maven.runtime.

[1] - https://www.slf4j.org/faq.html#changesInVersion200

m2e-maven-runtime/.gitignore

@@ -1,4 +1,3 @@
 .classpath
 .settings/
 .project
-META-INF/

m2e-maven-runtime/org.eclipse.m2e.maven.runtime/pom.xml

@@ -118,6 +118,7 @@
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-api</artifactId>
+			<version>2.0.7</version>
 			<scope>provided</scope>
 		</dependency>
 		<dependency>
@@ -173,8 +174,7 @@
 								org.eclipse.sisu.*;provider=m2e;mandatory:=provider;version=${maven-resolver.version}
 							Import-Package: \
 								org.slf4j;version="[1.7.31,3.0.0)",\
-								org.slf4j.spi;version="[1.7.31,3.0.0)",\
-								org.slf4j.helpers;version="[1.7.31,3.0.0)",\
+								org.slf4j.*;version="[1.7.31,3.0.0)",\
 								javax.inject;version="1.0.0",\
 								javax.annotation;version="[1.2.0,2.0.0)", \
 								org.apache.commons.cli;version="[1.4.0,2.0.0)"

m2e-maven-runtime/org.eclipse.m2e.maven.runtime/src/main/java/org/eclipse/m2e/slf4j2/provider/MavenSLF4JProvider.java

@@ -0,0 +1,58 @@
+/********************************************************************************
+ * Copyright (c) 2023, 2023 Hannes Wellmann and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *   Hannes Wellmann - initial API and implementation
+ ********************************************************************************/
+
+package org.eclipse.m2e.slf4j2.provider;
+
+import org.slf4j.ILoggerFactory;
+import org.slf4j.IMarkerFactory;
+import org.slf4j.helpers.BasicMarkerFactory;
+import org.slf4j.helpers.NOPMDCAdapter;
+import org.slf4j.impl.SimpleLoggerFactory;
+import org.slf4j.spi.MDCAdapter;
+import org.slf4j.spi.SLF4JServiceProvider;
+
+public class MavenSLF4JProvider implements SLF4JServiceProvider {
+	// Based on org.slf4j.simple.SimpleServiceProvider from org.slf4j:slf4j-simple
+
+	private ILoggerFactory loggerFactory;
+	private final IMarkerFactory markerFactory = new BasicMarkerFactory();
+	private final MDCAdapter mdcAdapter = new NOPMDCAdapter();
+
+	@Override
+	public ILoggerFactory getLoggerFactory() {
+		return loggerFactory;
+	}
+
+	@Override
+	public IMarkerFactory getMarkerFactory() {
+		return markerFactory;
+	}
+
+	@Override
+	public MDCAdapter getMDCAdapter() {
+		return mdcAdapter;
+	}
+
+	@Override
+	public String getRequestedApiVersion() {
+		// Declare the version of the maximum SLF4J API this implementation is
+		// compatible with. The value of this field is modified with each major release.
+		return "2.0.99";
+	}
+
+	@Override
+	public void initialize() {
+		loggerFactory = new SimpleLoggerFactory();
+	}
+
+}

m2e-maven-runtime/org.eclipse.m2e.maven.runtime/src/main/resources/META-INF/services/org.slf4j.spi.SLF4JServiceProvider

@@ -0,0 +1 @@
+org.eclipse.m2e.slf4j2.provider.MavenSLF4JProvider