IDEInjectorGenerator.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.util;

import org.apache.commons.io.FileUtils;
import org.eclipse.che.ide.api.extension.ExtensionGinModule;
import org.reflections.Reflections;

import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import static org.eclipse.che.util.IgnoreUnExistedResourcesReflectionConfigurationBuilder.*;

/**
 * This class looks for all the Gin Modules annotated with ExtensionGinModule annotation
 * and adds all them to IDEInjector class.
 *
 * @author <a href="mailto:nzamosenchuk@exoplatform.com">Nikolay Zamosenchuk</a>
 */
public class IDEInjectorGenerator {

    /** Set containing all the FQNs of GinModules */
    public static final Set<String> EXTENSIONS_FQN = new HashSet<>();
    /** Annotation to look for */
    protected static final String GIN_MODULE_ANNOTATION = "@ExtensionGinModule";

    /**
     * Path of the output class, it definitely should already exits. To ensure proper config.
     * File content will be overridden.
     */
    protected static final String IDE_INJECTOR_PATH =
            "org/eclipse/che/ide/client/inject/IDEInjector.java";

   
    /**
     * Entry point. --rootDir is the optional parameter.
     *
     * @param args
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {

        File rootFolder = GeneratorUtils.getRootFolder(args);
        System.out.println(" ------------------------------------------------------------------------ ");
        System.out.println(String.format("Searching for GinModules in %s", rootFolder.getAbsolutePath()));
        System.out.println(" ------------------------------------------------------------------------ ");
        // find all Extension FQNs
        findGinModules(rootFolder);
        generateExtensionManager(rootFolder);

    }

    /**
     * Generate to source of the Class
     *
     * @param rootFolder
     */
    public static void generateExtensionManager(File rootFolder) throws IOException {
        File extManager = new File(rootFolder, IDE_INJECTOR_PATH);
        StringBuilder builder = new StringBuilder();
        // declare package name
        builder.append("package org.eclipse.che.ide.client.inject;\n\n");

        // declare imports
        builder.append("import org.eclipse.che.ide.client.BootstrapController;\n");
        builder.append("import com.google.gwt.inject.client.GinModules;\n");
        builder.append("import com.google.gwt.inject.client.Ginjector;\n");
        builder.append("\n");

        // declare class Javadoc
        builder.append("/**\n");
        builder.append(" * THIS CLASS WILL BE OVERRIDDEN BY MAVEN BUILD. DON'T EDIT CLASS, IT WILL HAVE NO EFFECT.\n");
        builder.append(" * \n");
        builder.append(" * Interface for GIN Injector, that provides access to the top level\n");
        builder.append(" * application components. Implementation of Injector is generated\n");
        builder.append(" * on compile time.\n");
        builder.append(" */\n");
        builder.append("@GinModules({\n");
        // generate the list of modules includes
        generateListOfModules(builder);
        // close GinModules declaration
        builder.append("})\n");

        // declare class definition
        builder.append("public interface IDEInjector extends Ginjector\n");
        builder.append("{\n");
        builder.append("\n");
        // define method
        builder.append(GeneratorUtils.TAB).append("/**\n");
        builder.append(GeneratorUtils.TAB).append(" * @return the instance of BootstrapController\n");
        builder.append(GeneratorUtils.TAB).append(" */\n");
        builder.append(GeneratorUtils.TAB).append("BootstrapController getBootstrapController();\n");
        // close class definition
        builder.append("\n");
        builder.append("}\n");

        // flush content
        FileUtils.writeStringToFile(extManager, builder.toString());
    }

    /**
     * Generate codeblock with all the GinModules
     *
     * @param builder
     */
    public static void generateListOfModules(StringBuilder builder) {
        // Generate the list of GinModules declarations
        Iterator<String> entryIterator = EXTENSIONS_FQN.iterator();
        while (entryIterator.hasNext()) {
            // <FullFQN, ClassName>
            String ginModuleFQN = entryIterator.next();
            String hasComma = entryIterator.hasNext() ? "," : "";
            // add ModuleDeclaration
            builder.append(GeneratorUtils.TAB).append(ginModuleFQN).append(".class ").append(hasComma).append("\n");
        }
    }

    /**
     * Find all the Java files that have ExtensionGinModule annotation
     *
     * @throws IOException
     */
    @SuppressWarnings("unchecked")
    public static void findGinModules(File rootFolder) throws IOException {
        Reflections reflection = new Reflections(getConfigurationBuilder());

        Set<Class<?>> classes = reflection.getTypesAnnotatedWith(ExtensionGinModule.class);
        for (Class clazz : classes) {
            EXTENSIONS_FQN.add(clazz.getCanonicalName());
            System.out.println(String.format("New Gin Module Found: %s", clazz.getCanonicalName()));
        }
        System.out.println(String.format("Found: %d Gin Modules", EXTENSIONS_FQN.size()));
    }

}