src/main/java/org/apache/maven/plugins/toolchain/ToolchainMojo.java

/*
 * 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.plugins.toolchain;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.plugin.AbstractMojo;
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.LifecyclePhase;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.apache.maven.toolchain.MisconfiguredToolchainException;
import org.apache.maven.toolchain.ToolchainManagerPrivate;
import org.apache.maven.toolchain.ToolchainPrivate;

/**
 * Check that toolchains requirements are met by currently configured toolchains and
 * store the selected toolchains in build context for later retrieval by other plugins.
 *
 * @author mkleint
 */
@Mojo(
        name = "toolchain",
        defaultPhase = LifecyclePhase.VALIDATE,
        configurator = "toolchains-requirement-configurator",
        threadSafe = true)
public class ToolchainMojo extends AbstractMojo {
    private static final Object LOCK = new Object();

    /**
     */
    @Component
    private ToolchainManagerPrivate toolchainManagerPrivate;

    /**
     * The current build session instance. This is used for toolchain manager API calls.
     */
    @Parameter(defaultValue = "${session}", readonly = true, required = true)
    private MavenSession session;

    /**
     * Toolchains requirements, specified by one
     * <pre>  &lt;toolchain-type&gt;
     *    &lt;param&gt;expected value&lt;/param&gt;
     *    ...
     *  &lt;/toolchain-type&gt;</pre>
     * element for each required toolchain.
     */
    @Parameter(required = true)
    private ToolchainsRequirement toolchains;

    @Override
    public void execute() throws MojoExecutionException, MojoFailureException {
        if (toolchains == null) {
            // should not happen since parameter is required...
            getLog().warn("No toolchains requirements configured.");
            return;
        }

        List<String> nonMatchedTypes = new ArrayList<>();

        for (Map.Entry<String, Map<String, String>> entry :
                toolchains.getToolchains().entrySet()) {
            String type = entry.getKey();

            if (!selectToolchain(type, entry.getValue())) {
                nonMatchedTypes.add(type);
            }
        }

        if (!nonMatchedTypes.isEmpty()) {
            // TODO add the default toolchain instance if defined??
            StringBuilder buff = new StringBuilder();
            buff.append("Cannot find matching toolchain definitions for the following toolchain types:");

            for (String type : nonMatchedTypes) {
                buff.append(System.lineSeparator());
                buff.append(getToolchainRequirementAsString(type, toolchains.getParams(type)));
            }

            getLog().error(buff.toString());

            throw new MojoFailureException(buff.toString() + System.lineSeparator()
                    + "Please make sure you define the required toolchains in your ~/.m2/toolchains.xml file.");
        }
    }

    protected String getToolchainRequirementAsString(String type, Map<String, String> params) {
        StringBuilder buff = new StringBuilder();

        buff.append(type).append(" [");

        if (params.size() == 0) {
            buff.append(" any");
        } else {
            for (Map.Entry<String, String> param : params.entrySet()) {
                buff.append(" ").append(param.getKey()).append("='").append(param.getValue());
                buff.append("'");
            }
        }

        buff.append(" ]");

        return buff.toString();
    }

    protected boolean selectToolchain(String type, Map<String, String> params) throws MojoExecutionException {
        getLog().info("Required toolchain: " + getToolchainRequirementAsString(type, params));
        int typeFound = 0;

        try {
            ToolchainPrivate[] tcs = getToolchains(type);

            for (ToolchainPrivate tc : tcs) {
                if (!type.equals(tc.getType())) {
                    // useful because of MNG-5716
                    continue;
                }

                typeFound++;

                if (tc.matchesRequirements(params)) {
                    getLog().info("Found matching toolchain for type " + type + ": " + tc);

                    // store matching toolchain to build context
                    synchronized (LOCK) {
                        toolchainManagerPrivate.storeToolchainToBuildContext(tc, session);
                    }

                    return true;
                }
            }
        } catch (MisconfiguredToolchainException ex) {
            throw new MojoExecutionException("Misconfigured toolchains.", ex);
        }

        getLog().error("No toolchain " + ((typeFound == 0) ? "found" : ("matched from " + typeFound + " found"))
                + " for type " + type);

        return false;
    }

    private ToolchainPrivate[] getToolchains(String type)
            throws MojoExecutionException, MisconfiguredToolchainException {
        return toolchainManagerPrivate.getToolchainsForType(type, session);
    }
}