Add toolchains support for Spring Boot Maven Plugin

See gh-18732

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -239,6 +239,7 @@
 		<versions-maven-plugin.version>2.7</versions-maven-plugin.version>
 		<xml-maven-plugin.version>1.0.2</xml-maven-plugin.version>
 		<flatten-maven-plugin.version>1.1.0</flatten-maven-plugin.version>
+		<maven-toolchains-plugin.version>3.0.0</maven-toolchains-plugin.version>
 	</properties>
 	<dependencyManagement>
 		<dependencies>
@@ -3337,6 +3338,11 @@
 					<artifactId>maven-war-plugin</artifactId>
 					<version>${maven-war-plugin.version}</version>
 				</plugin>
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-toolchains-plugin</artifactId>
+					<version>${maven-toolchains-plugin.version}</version>
+				</plugin>
 				<plugin>
 					<groupId>org.codehaus.mojo</groupId>
 					<artifactId>build-helper-maven-plugin</artifactId>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/invoker.properties

@@ -0,0 +1,2 @@
+invoker.goals=clean verify -t toolchains.xml
+invoker.os.family=!windows

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/jdkHome/bin/java

@@ -0,0 +1,2 @@
+#!/bin/bash
+echo 'The Maven Toolchains is awesome!'

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/pom.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>run-toolchains</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-toolchains-plugin</artifactId>
+				<version>@maven-toolchains-plugin.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>toolchain</goal>
+						</goals>
+					</execution>
+				</executions>
+				<configuration>
+					<toolchains>
+						<jdk/>
+					</toolchains>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<phase>package</phase>
+						<goals>
+							<goal>run</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.test;
+
+public class SampleApplication {
+
+	public static void main(String[] args) {
+		throw new IllegalStateException("Should not be called!");
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/toolchains.xml

@@ -0,0 +1,8 @@
+<toolchains>
+	<toolchain>
+		<type>jdk</type>
+		<configuration>
+			<jdkHome>jdkHome</jdkHome>
+		</configuration>
+	</toolchain>
+</toolchains>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/it/run-toolchains/verify.groovy

@@ -0,0 +1,3 @@
+def file = new File(basedir, "build.log")
+return file.text.contains("The Maven Toolchains is awesome!")
+

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/AbstractRunMojo.java

@@ -30,15 +30,20 @@ import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.apache.maven.artifact.Artifact;
+import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Resource;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.apache.maven.plugin.MojoFailureException;
+import org.apache.maven.plugins.annotations.Component;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.shared.artifact.filter.collection.AbstractArtifactFeatureFilter;
 import org.apache.maven.shared.artifact.filter.collection.FilterArtifacts;
+import org.apache.maven.toolchain.Toolchain;
+import org.apache.maven.toolchain.ToolchainManager;
 
 import org.springframework.boot.loader.tools.FileUtils;
+import org.springframework.boot.loader.tools.JavaExecutable;
 import org.springframework.boot.loader.tools.MainClassFinder;
 
 /**
@@ -204,6 +209,20 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 	@Parameter(property = "spring-boot.run.skip", defaultValue = "false")
 	private boolean skip;
 
+	/**
+	 * The Maven Session Object.
+	 * @since 2.2.1
+	 */
+	@Parameter(defaultValue = "${session}", readonly = true)
+	private MavenSession session;
+
+	/**
+	 * The toolchain manager to use.
+	 * @since 2.2.1
+	 */
+	@Component
+	private ToolchainManager toolchainManager;
+
 	@Override
 	public void execute() throws MojoExecutionException, MojoFailureException {
 		if (this.skip) {
@@ -325,6 +344,16 @@ public abstract class AbstractRunMojo extends AbstractDependencyFilterMojo {
 		return runArguments;
 	}
 
+	/**
+	 * Provides access to the java binary executable, regardless of OS.
+	 * @return the java executable
+	 **/
+	protected String getJavaExecutable() {
+		Toolchain toolchain = this.toolchainManager.getToolchainFromBuildContext("jdk", this.session);
+		String javaExecutable = (toolchain != null) ? toolchain.findTool("java") : null;
+		return (javaExecutable != null) ? javaExecutable : new JavaExecutable().toString();
+	}
+
 	/**
 	 * Resolve the environment variables to use.
 	 * @return an {@link EnvVariables} defining the environment variables

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RunMojo.java

@@ -30,7 +30,6 @@ import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.ResolutionScope;
 
-import org.springframework.boot.loader.tools.JavaExecutable;
 import org.springframework.boot.loader.tools.RunProcess;
 
 /**
@@ -111,7 +110,7 @@ public class RunMojo extends AbstractRunMojo {
 	private int forkJvm(File workingDirectory, List<String> args, Map<String, String> environmentVariables)
 			throws MojoExecutionException {
 		try {
-			RunProcess runProcess = new RunProcess(workingDirectory, new JavaExecutable().toString());
+			RunProcess runProcess = new RunProcess(workingDirectory, getJavaExecutable());
 			Runtime.getRuntime().addShutdownHook(new Thread(new RunProcessKiller(runProcess)));
 			return runProcess.run(true, args, environmentVariables);
 		}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/StartMojo.java

@@ -37,7 +37,6 @@ import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.ResolutionScope;
 
-import org.springframework.boot.loader.tools.JavaExecutable;
 import org.springframework.boot.loader.tools.RunProcess;
 
 /**
@@ -104,7 +103,7 @@ public class StartMojo extends AbstractRunMojo {
 	private RunProcess runProcess(File workingDirectory, List<String> args, Map<String, String> environmentVariables)
 			throws MojoExecutionException {
 		try {
-			RunProcess runProcess = new RunProcess(workingDirectory, new JavaExecutable().toString());
+			RunProcess runProcess = new RunProcess(workingDirectory, getJavaExecutable());
 			runProcess.run(false, args, environmentVariables);
 			return runProcess;
 		}