Promote java version in JavaToolchain

api/maven-api-core/src/main/java/org/apache/maven/api/JavaToolchain.java

@@ -42,4 +42,6 @@
 public interface JavaToolchain extends Toolchain {
 
     String getJavaHome();
+
+    Version getJavaVersion();
 }

compat/maven-compat/src/main/java/org/apache/maven/toolchain/java/JavaToolchain.java

@@ -18,6 +18,7 @@
  */
 package org.apache.maven.toolchain.java;
 
+import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.toolchain.Toolchain;
 
 /**
@@ -27,4 +28,8 @@
  * @deprecated Use {@link org.apache.maven.api.JavaToolchain} instead.
  */
 @Deprecated(since = "4.0.0")
-public interface JavaToolchain extends Toolchain {}
+public interface JavaToolchain extends Toolchain {
+    String getJavaHome();
+
+    ArtifactVersion getJavaVersion();
+}

compat/maven-compat/src/main/java/org/apache/maven/toolchain/java/JavaToolchainFactory.java

@@ -21,9 +21,12 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Properties;
 
+import org.apache.maven.artifact.versioning.ArtifactVersion;
+import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 import org.apache.maven.toolchain.MisconfiguredToolchainException;
 import org.apache.maven.toolchain.RequirementMatcher;
 import org.apache.maven.toolchain.RequirementMatcherFactory;
@@ -93,6 +96,14 @@ public ToolchainPrivate createToolchain(ToolchainModel model) throws Misconfigur
                     "Non-existing JDK home configuration at " + normal.toAbsolutePath());
         }
 
+        ArtifactVersion javaVersion = model.getProvides().entrySet().stream()
+                .filter(entry -> "version".equals(entry.getKey()))
+                .map(Map.Entry::getValue)
+                .map(v -> new DefaultArtifactVersion((String) v))
+                .findAny()
+                .orElse(null);
+
+        jtc.setJavaVersion(javaVersion);
         return jtc;
     }
 

compat/maven-compat/src/main/java/org/apache/maven/toolchain/java/JavaToolchainImpl.java

@@ -22,6 +22,7 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
+import org.apache.maven.artifact.versioning.ArtifactVersion;
 import org.apache.maven.toolchain.DefaultToolchain;
 import org.apache.maven.toolchain.model.ToolchainModel;
 import org.apache.maven.utils.Os;
@@ -39,6 +40,8 @@ public class JavaToolchainImpl extends DefaultToolchain implements JavaToolchain
 
     public static final String KEY_JAVAHOME = "jdkHome"; // NOI18N
 
+    private ArtifactVersion javaVersion;
+
     JavaToolchainImpl(ToolchainModel model, Logger logger) {
         super(model, "jdk", logger);
     }
@@ -47,6 +50,15 @@ public String getJavaHome() {
         return javaHome;
     }
 
+    @Override
+    public ArtifactVersion getJavaVersion() {
+        return javaVersion;
+    }
+
+    public void setJavaVersion(ArtifactVersion javaVersion) {
+        this.javaVersion = javaVersion;
+    }
+
     public void setJavaHome(String javaHome) {
         this.javaHome = javaHome;
     }

compat/maven-compat/src/test/java/org/apache/maven/toolchain/java/JavaToolchainFactoryTest.java

@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.toolchain.java;
+
+import org.apache.maven.toolchain.MisconfiguredToolchainException;
+import org.apache.maven.toolchain.model.ToolchainModel;
+import org.codehaus.plexus.util.xml.Xpp3Dom;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+@SuppressWarnings("deprecation")
+class JavaToolchainFactoryTest {
+
+    private JavaToolchainFactory factory;
+
+    @BeforeEach
+    void setup() {
+        factory = new JavaToolchainFactory();
+    }
+
+    @Test
+    void defaultToolchainShouldReturnEmpty() {
+        assertNull(factory.createDefaultToolchain());
+    }
+
+    @Test
+    void missingJdkHomeShouldThrowException() {
+        ToolchainModel toolchainModel = new ToolchainModel();
+        MisconfiguredToolchainException exception = Assertions.assertThrows(
+                MisconfiguredToolchainException.class, () -> factory.createToolchain(toolchainModel));
+        assertEquals("Java toolchain without the jdkHome configuration element.", exception.getMessage());
+    }
+
+    @Test
+    void nonExistingJdkHomeShouldThrowException() {
+        ToolchainModel toolchainModel = new ToolchainModel();
+        Xpp3Dom jdkHome = new Xpp3Dom("jdkHome");
+        jdkHome.setValue("/not-exist/jdk/home");
+        Xpp3Dom configuration = new Xpp3Dom("configuration");
+        configuration.addChild(jdkHome);
+        toolchainModel.setConfiguration(configuration);
+
+        MisconfiguredToolchainException exception = Assertions.assertThrows(
+                MisconfiguredToolchainException.class, () -> factory.createToolchain(toolchainModel));
+        assertTrue(
+                exception.getMessage().contains("Non-existing JDK home configuration at"),
+                "Not expected exception message: '" + exception.getMessage());
+        assertTrue(
+                exception.getMessage().contains("not-exist"),
+                "Not expected exception message: '" + exception.getMessage() + "', should contain: 'not-exist'");
+    }
+
+    @Test
+    void properToolchainShouldReturnJavaToolchain() throws Exception {
+        String javaHome = System.getProperty("java.home");
+        String javaVersion = System.getProperty("java.version");
+
+        ToolchainModel toolchainModel = new ToolchainModel();
+        Xpp3Dom jdkHome = new Xpp3Dom("jdkHome");
+        jdkHome.setValue(javaHome);
+        Xpp3Dom configuration = new Xpp3Dom("configuration");
+        configuration.addChild(jdkHome);
+        toolchainModel.setConfiguration(configuration);
+
+        toolchainModel.addProvide("version", javaVersion);
+
+        JavaToolchain toolchain = (JavaToolchain) factory.createToolchain(toolchainModel);
+        assertNotNull(toolchain);
+        assertEquals(javaHome, toolchain.getJavaHome());
+        assertEquals(javaVersion, toolchain.getJavaVersion().toString());
+    }
+}

impl/maven-impl/src/main/java/org/apache/maven/impl/DefaultJavaToolchainFactory.java

@@ -87,7 +87,14 @@ public JavaToolchain createToolchain(@Nonnull ToolchainModel model) {
         }
         String javaHome = normal.toString();
 
-        return new DefaultJavaToolchain(model, javaHome, matchers);
+        Version javaVersion = model.getProvides().entrySet().stream()
+                .filter(entry -> "version".equals(entry.getKey()))
+                .map(Map.Entry::getValue)
+                .map(versionParser::parseVersion)
+                .findAny()
+                .orElse(null);
+
+        return new DefaultJavaToolchain(model, javaHome, javaVersion, matchers);
     }
 
     @Nonnull
@@ -102,9 +109,13 @@ static class DefaultJavaToolchain implements JavaToolchain {
         final String javaHome;
         final Map<String, Predicate<String>> matchers;
 
-        DefaultJavaToolchain(ToolchainModel model, String javaHome, Map<String, Predicate<String>> matchers) {
+        private Version javaVersion;
+
+        DefaultJavaToolchain(
+                ToolchainModel model, String javaHome, Version javaVersion, Map<String, Predicate<String>> matchers) {
             this.model = model;
             this.javaHome = javaHome;
+            this.javaVersion = javaVersion;
             this.matchers = matchers;
         }
 
@@ -113,6 +124,11 @@ public String getJavaHome() {
             return javaHome;
         }
 
+        @Override
+        public Version getJavaVersion() {
+            return javaVersion;
+        }
+
         @Override
         public String getType() {
             return "jdk";

impl/maven-impl/src/test/java/org/apache/maven/impl/DefaultJavaToolchainFactoryTest.java

@@ -0,0 +1,97 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.impl;
+
+import java.util.List;
+import java.util.Map;
+
+import org.apache.maven.api.JavaToolchain;
+import org.apache.maven.api.services.ToolchainFactoryException;
+import org.apache.maven.api.services.VersionParser;
+import org.apache.maven.api.toolchain.ToolchainModel;
+import org.apache.maven.api.xml.XmlNode;
+import org.apache.maven.impl.resolver.MavenVersionScheme;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class DefaultJavaToolchainFactoryTest {
+
+    private DefaultJavaToolchainFactory factory;
+
+    @BeforeEach
+    void setUp() {
+        VersionParser versionParser = new DefaultVersionParser(new DefaultModelVersionParser(new MavenVersionScheme()));
+        factory = new DefaultJavaToolchainFactory(versionParser);
+    }
+
+    @Test
+    void defaultToolchainShouldReturnEmpty() {
+        assertTrue(factory.createDefaultToolchain().isEmpty());
+    }
+
+    @Test
+    void missingJdkHomeShouldThrowException() {
+        ToolchainModel toolchainModel = ToolchainModel.newBuilder().build();
+        ToolchainFactoryException exception =
+                Assertions.assertThrows(ToolchainFactoryException.class, () -> factory.createToolchain(toolchainModel));
+        assertEquals("Java toolchain without the jdkHome configuration element.", exception.getMessage());
+    }
+
+    @Test
+    void nonExistingJdkHomeShouldThrowException() {
+        ToolchainModel toolchainModel = ToolchainModel.newBuilder()
+                .configuration(XmlNode.newBuilder()
+                        .name("configuration")
+                        .children(List.of(XmlNode.newInstance("jdkHome", "/not-exist/jdk/home")))
+                        .build())
+                .build();
+
+        ToolchainFactoryException exception =
+                Assertions.assertThrows(ToolchainFactoryException.class, () -> factory.createToolchain(toolchainModel));
+        assertTrue(
+                exception.getMessage().contains("Non-existing JDK home configuration at"),
+                "Not expected exception message: '" + exception.getMessage());
+        assertTrue(
+                exception.getMessage().contains("not-exist"),
+                "Not expected exception message: '" + exception.getMessage() + "', should contain: 'not-exist'");
+    }
+
+    @Test
+    void properToolchainShouldReturnJavaToolchain() {
+        String javaHome = System.getProperty("java.home");
+        String javaVersion = System.getProperty("java.version");
+        ToolchainModel toolchainModel = ToolchainModel.newBuilder()
+                .provides(Map.of("version", javaVersion))
+                .configuration(XmlNode.newBuilder()
+                        .name("configuration")
+                        .children(List.of(XmlNode.newInstance("jdkHome", javaHome)))
+                        .build())
+                .build();
+
+        JavaToolchain toolchain = factory.createToolchain(toolchainModel);
+        assertNotNull(toolchain);
+        assertEquals(javaHome, toolchain.getJavaHome());
+        assertEquals(javaVersion, toolchain.getJavaVersion().toString());
+    }
+}