src/it/setup-custom-toolchain/src/main/java/org/apache/maven/plugins/toolchains/its/custom/CustomToolchainFactory.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.toolchains.its.custom;

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.Properties;

import org.apache.maven.toolchain.MisconfiguredToolchainException;
import org.apache.maven.toolchain.RequirementMatcher;
import org.apache.maven.toolchain.RequirementMatcherFactory;
import org.apache.maven.toolchain.ToolchainFactory;
import org.apache.maven.toolchain.ToolchainPrivate;
import org.apache.maven.toolchain.model.ToolchainModel;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.Logger;
import org.codehaus.plexus.util.FileUtils;
import org.codehaus.plexus.util.xml.Xpp3Dom;

/**
 * Custom toolchain factory, declared as <code>ToolchainFactory</code> Plexus component with <code>custom</code>
 * hint.
 *
 * @author Hervé Boutemy
 */
@Component(role = ToolchainFactory.class, hint = "custom")
public class CustomToolchainFactory implements ToolchainFactory {

    @Requirement
    private Logger logger;

    public ToolchainPrivate createToolchain(ToolchainModel model) throws MisconfiguredToolchainException {
        if (model == null) {
            return null;
        }

        CustomToolchainImpl customToolchain = new CustomToolchainImpl(model, logger);

        // populate the provides section
        Properties provides = getProvidesProperties(model);

        for (Map.Entry<Object, Object> provide : provides.entrySet()) {
            String key = (String) provide.getKey();
            String value = (String) provide.getValue();

            if (value == null) {
                throw new MisconfiguredToolchainException(
                        "Provides token '" + key + "' doesn't have any value configured.");
            }

            RequirementMatcher matcher;
            if ("version".equals(key)) {
                matcher = RequirementMatcherFactory.createVersionMatcher(value);
            } else {
                matcher = RequirementMatcherFactory.createExactMatcher(value);
            }

            customToolchain.addProvideToken(key, matcher);
        }

        // populate the configuration section
        Properties configuration = toProperties((Xpp3Dom) model.getConfiguration());

        String toolHome = configuration.getProperty(CustomToolchainImpl.KEY_TOOLHOME);
        if (toolHome == null) {
            throw new MisconfiguredToolchainException(
                    "Custom toolchain without the " + CustomToolchainImpl.KEY_TOOLHOME + " configuration element.");
        }

        toolHome = FileUtils.normalize(toolHome);
        customToolchain.setToolHome(toolHome);

        if (!new File(toolHome).exists()) {
            throw new MisconfiguredToolchainException(
                    "Non-existing tool home configuration at " + new File(toolHome).getAbsolutePath());
        }

        return customToolchain;
    }

    public ToolchainPrivate createDefaultToolchain() {
        // not sure it's necessary to provide a default toolchain here.
        return null;
    }

    protected Logger getLogger() {
        return logger;
    }

    /**
     * Get <code>provides</code> properties in in a way compatible with toolchains descriptor version 1.0
     * (Maven 2.0.9 to 3.2.3, where it is represented as Object/DOM) and descriptor version 1.1
     * (Maven 3.2.4 and later, where it is represented as Properties).
     *
     * @param model the toolchain model as read from XML
     * @return the properties defined in the <code>provides</code> element
     * @see <a href="https://issues.apache.org/jira/browse/MNG-5718">MNG-5718</a>
     */
    protected Properties getProvidesProperties(ToolchainModel model) {
        Object value = getBeanProperty(model, "provides");

        return (value instanceof Properties) ? (Properties) value : toProperties((Xpp3Dom) value);
    }

    protected Properties toProperties(Xpp3Dom dom) {
        Properties props = new Properties();

        Xpp3Dom[] children = dom.getChildren();
        for (Xpp3Dom child : children) {
            props.put(child.getName(), child.getValue());
        }

        return props;
    }

    protected Object getBeanProperty(Object obj, String property) {
        try {
            Method method = new PropertyDescriptor(property, obj.getClass()).getReadMethod();

            return method.invoke(obj);
        } catch (IntrospectionException e) {
            throw new RuntimeException("Incompatible toolchain API", e);
        } catch (IllegalAccessException e) {
            throw new RuntimeException("Incompatible toolchain API", e);
        } catch (InvocationTargetException e) {
            Throwable cause = e.getCause();

            if (cause instanceof RuntimeException) {
                throw (RuntimeException) cause;
            }

            throw new RuntimeException("Incompatible toolchain API", e);
        }
    }
}