private Toolchain getToolchain()
{
    Toolchain tc = null;

    try
    {
        if ( session != null ) // session is null in tests..
        {
            ToolchainManager toolchainManager =
                (ToolchainManager) session.getContainer().lookup( ToolchainManager.ROLE );

            if ( toolchainManager != null )
            {
                tc = toolchainManager.getToolchainFromBuildContext( toolchain, session );
            }
        }
    }
    catch ( ComponentLookupException componentLookupException )
    {
        // just ignore, could happen in pre-2.0.9 builds..
    }
    return tc;
}
 

private File getJavaExecutable() throws MojoExecutionException {
    if (javaExecutable != null) {
        getLog().debug("Plugin configuration set the 'javaExecutable' parameter to " + javaExecutable);
    } else {
        Toolchain tc = toolchainManager.getToolchainFromBuildContext("jdk", mavenSession);
        if (tc != null) {
            getLog().info("Using toolchain " + tc + " to find the java executable");
            javaExecutable = tc.findTool("java");
        } else {
            getLog().debug("The java executable is set to default value");
            javaExecutable = SystemUtils.getJavaHome() + File.separator + "bin" + File.separator + "java";
        }
    }
    String exe = SystemUtils.IS_OS_WINDOWS && !javaExecutable.endsWith(".exe") ? ".exe" : "";
    File javaExe = new File(javaExecutable + exe);
    if (!javaExe.isFile()) {
        throw new MojoExecutionException("The java executable '" + javaExe + "' doesn't exist or is not a file."
            + " Verify the <javaExecutable/> parameter or toolchain configuration.");
    }
    getLog().info("The java executable is " + javaExe.getAbsolutePath());
    return javaExe;
}
 

private String getBootClassPath() {
	Toolchain toolchain = toolchainManager.getToolchainFromBuildContext("jdk", session);
	if (toolchain instanceof DefaultJavaToolChain) {
		DefaultJavaToolChain javaToolChain = (DefaultJavaToolChain) toolchain;
		getLog().info("Using toolchain " + javaToolChain);

		if (javaSourceVersion != null) {
			JavaVersion version = JavaVersion.fromQualifier(javaSourceVersion);
			if (version.isAtLeast(JavaVersion.JAVA9)) {
				return ""; // bootclasspath only supported on Java8 and older
			}
		}

		String[] includes = { "jre/lib/*", "jre/lib/ext/*", "jre/lib/endorsed/*" };
		String[] excludes = new String[0];
		Xpp3Dom config = (Xpp3Dom) javaToolChain.getModel().getConfiguration();
		if (config != null) {
			Xpp3Dom bootClassPath = config.getChild("bootClassPath");
			if (bootClassPath != null) {
				Xpp3Dom includeParent = bootClassPath.getChild("includes");
				if (includeParent != null) {
					includes = getValues(includeParent.getChildren("include"));
				}
				Xpp3Dom excludeParent = bootClassPath.getChild("excludes");
				if (excludeParent != null) {
					excludes = getValues(excludeParent.getChildren("exclude"));
				}
			}
		}

		return scanBootclasspath(javaToolChain.getJavaHome(), includes, excludes);
	}
	return "";
}
 

/** Replies the boot classpath.
 *
 * @return the boot classpath.
 * @throws IOException in case of error.
 */
protected String getBootClassPath() throws IOException {
	final Toolchain toolchain = this.toolchainManager.getToolchainFromBuildContext("jdk", this.session); //$NON-NLS-1$
	if (toolchain instanceof JavaToolchain && toolchain instanceof ToolchainPrivate) {
		final JavaToolchain javaToolChain = (JavaToolchain) toolchain;
		final ToolchainPrivate privateJavaToolChain = (ToolchainPrivate) toolchain;
		String[] includes = {"jre/lib/*", "jre/lib/ext/*", "jre/lib/endorsed/*"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		String[] excludes = new String[0];
		final Xpp3Dom config = (Xpp3Dom) privateJavaToolChain.getModel().getConfiguration();
		if (config != null) {
			final Xpp3Dom bootClassPath = config.getChild("bootClassPath"); //$NON-NLS-1$
			if (bootClassPath != null) {
				final Xpp3Dom includeParent = bootClassPath.getChild("includes"); //$NON-NLS-1$
				if (includeParent != null) {
					includes = getValues(includeParent.getChildren("include")); //$NON-NLS-1$
				}
				final Xpp3Dom excludeParent = bootClassPath.getChild("excludes"); //$NON-NLS-1$
				if (excludeParent != null) {
					excludes = getValues(excludeParent.getChildren("exclude")); //$NON-NLS-1$
				}
			}
		}

		try {
			return scanBootclasspath(Objects.toString(this.reflect.invoke(javaToolChain, "getJavaHome")), includes, excludes); //$NON-NLS-1$
		} catch (Exception e) {
			throw new IOException(e.getLocalizedMessage(), e);
		}
	}
	return ""; //$NON-NLS-1$
}
 

private String getBootClassPath() throws MojoExecutionException {
	// Bootclasspath is only supported on Java8 and older
	final String sourceVersionStr = getSourceVersion();
	if (!Strings.isEmpty(sourceVersionStr)) {
		final JavaVersion sourceVersion = JavaVersion.fromQualifier(sourceVersionStr);
		if (sourceVersion != null && sourceVersion.isAtLeast(JavaVersion.JAVA9)) {
			return ""; //$NON-NLS-1$
		}
	}
	final Toolchain toolchain = this.toolchainManager.getToolchainFromBuildContext("jdk", this.mavenHelper.getSession()); //$NON-NLS-1$
	if (toolchain instanceof JavaToolchain && toolchain instanceof ToolchainPrivate) {
		final JavaToolchain javaToolChain = (JavaToolchain) toolchain;
		final ToolchainPrivate privateJavaToolChain = (ToolchainPrivate) toolchain;
		getLog().info(MessageFormat.format(Messages.AbstractSarlBatchCompilerMojo_5, javaToolChain));

		String[] includes = {"jre/lib/*", "jre/lib/ext/*", "jre/lib/endorsed/*"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		String[] excludes = new String[0];
		final Xpp3Dom config = (Xpp3Dom) privateJavaToolChain.getModel().getConfiguration();
		if (config != null) {
			final Xpp3Dom bootClassPath = config.getChild("bootClassPath"); //$NON-NLS-1$
			if (bootClassPath != null) {
				final Xpp3Dom includeParent = bootClassPath.getChild("includes"); //$NON-NLS-1$
				if (includeParent != null) {
					includes = getValues(includeParent.getChildren("include")); //$NON-NLS-1$
				}
				final Xpp3Dom excludeParent = bootClassPath.getChild("excludes"); //$NON-NLS-1$
				if (excludeParent != null) {
					excludes = getValues(excludeParent.getChildren("exclude")); //$NON-NLS-1$
				}
			}
		}

		try {
			return scanBootclasspath(Objects.toString(this.reflect.invoke(javaToolChain, "getJavaHome")), includes, excludes); //$NON-NLS-1$
		} catch (Exception e) {
			throw new MojoExecutionException(e.getLocalizedMessage(), e);
		}
	}
	return ""; //$NON-NLS-1$
}