Groovy example source code file (FileSystemCompiler.java)

This example Groovy source code file (FileSystemCompiler.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

compilationunit, compilerconfiguration, exception, file, file, filesystemcompiler, io, ioexception, net, network, options, options, print, specify, specify, string, string, util

The Groovy FileSystemCompiler.java source code

/*
 * Copyright 2003-2010 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
 *
 *     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.codehaus.groovy.tools;

import groovy.lang.GroovyResourceLoader;
import org.apache.commons.cli.*;
import org.codehaus.groovy.control.CompilationUnit;
import org.codehaus.groovy.control.CompilerConfiguration;
import org.codehaus.groovy.control.ConfigurationException;
import org.codehaus.groovy.tools.javac.JavaAwareCompilationUnit;

import groovy.lang.GroovySystem;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.*;

/**
 * Command-line compiler (aka. <tt>groovyc).
 *
 * @version $Id: FileSystemCompiler.java 21459 2011-02-03 13:01:54Z ait $
 */
public class FileSystemCompiler {
    private final CompilationUnit unit;

    public FileSystemCompiler(CompilerConfiguration configuration) throws ConfigurationException {
        this(configuration, null);
    }

    public FileSystemCompiler(CompilerConfiguration configuration, CompilationUnit cu) throws ConfigurationException {
        if (cu != null) {
            unit = cu;
        } else if (configuration.getJointCompilationOptions() != null) {
            unit = new JavaAwareCompilationUnit(configuration);
        } else {
            unit = new CompilationUnit(configuration);
        }

        // in command line we don't need to do script lookups
        unit.getClassLoader().setResourceLoader(new GroovyResourceLoader() {
            public URL loadGroovySource(String filename) throws MalformedURLException {
                return null;
            }
        });
    }

    public void compile(String[] paths) throws Exception {
        unit.addSources(paths);
        unit.compile();
    }

    public void compile(File[] files) throws Exception {
        unit.addSources(files);
        unit.compile();
    }

    public static void displayHelp(final Options options) {
        final HelpFormatter formatter = new HelpFormatter();
        formatter.printHelp(80, "groovyc [options] <source-files>", "options:", options, "");
    }

    public static void displayVersion() {
        String version = GroovySystem.getVersion();
        System.err.println("Groovy compiler version " + version);
        System.err.println("Copyright 2003-2010 The Codehaus. http://groovy.codehaus.org/");
        System.err.println("");
    }

    public static int checkFiles(String[] filenames) {
        int errors = 0;

        for (String filename : filenames) {
            File file = new File(filename);
            if (!file.exists()) {
                System.err.println("error: file not found: " + file);
                ++errors;
            } else if (!file.canRead()) {
                System.err.println("error: file not readable: " + file);
                ++errors;
            }
        }

        return errors;
    }

    public static boolean validateFiles(String[] filenames) {
        return checkFiles(filenames) == 0;
    }

    private static boolean displayStackTraceOnError = false;

    /**
     * Same as main(args) except that exceptions are thrown out instead of causing
     * the VM to exit.
     */
    public static void commandLineCompile(String[] args) throws Exception {
        Options options = createCompilationOptions();

        PosixParser cliParser = new PosixParser();

        CommandLine cli;
        cli = cliParser.parse(options, args);

        if (cli.hasOption('h')) {
            displayHelp(options);
            return;
        }

        if (cli.hasOption('v')) {
            displayVersion();
            return;
        }

        displayStackTraceOnError = cli.hasOption('e');

        CompilerConfiguration configuration = generateCompilerConfigurationFromOptions(cli);

        //
        // Load the file name list
        String[] filenames = generateFileNamesFromOptions(cli);
        boolean fileNameErrors = filenames == null;
        if (!fileNameErrors && (filenames.length == 0)) {
            displayHelp(options);
            return;
        }

        fileNameErrors = fileNameErrors && !validateFiles(filenames);

        if (!fileNameErrors) {
            doCompilation(configuration, null, filenames);
        }
    }

    /**
     * Primary entry point for compiling from the command line
     * (using the groovyc script).
     *
     * If calling inside a process and you don't want the JVM to exit on an
     * error call commandLineCompile(String[]), which this method simply wraps 
     */
    public static void main(String[] args) {

        try {
            commandLineCompile(args);
        } catch( Throwable e ) {
            new ErrorReporter( e, displayStackTraceOnError).write( System.err );
            System.exit(1);
        }
    }

    public static void doCompilation(CompilerConfiguration configuration, CompilationUnit unit, String[] filenames) throws Exception {
        File tmpDir = null;
        // if there are any joint compilation options set stubDir if not set
        try {
            if ((configuration.getJointCompilationOptions() != null)
                && !configuration.getJointCompilationOptions().containsKey("stubDir"))
            {
                tmpDir = createTempDir();
                configuration.getJointCompilationOptions().put("stubDir", tmpDir);
            }
            FileSystemCompiler compiler = new FileSystemCompiler(configuration, unit);
            compiler.compile(filenames);
        } finally {
            try {
                if (tmpDir != null) deleteRecursive(tmpDir);
            } catch (Throwable t) {
                System.err.println("error: could not delete temp files - " + tmpDir.getPath());
            }
        }
    }

    public static String[] generateFileNamesFromOptions(CommandLine cli) {
        String[] filenames = cli.getArgs();
        List<String> fileList = new ArrayList(filenames.length);
        boolean errors = false;
        for (String filename : filenames) {
            if (filename.startsWith("@")) {
                try {
                    BufferedReader br = new BufferedReader(new FileReader(filename.substring(1)));
                    String file;
                    while ((file = br.readLine()) != null) {
                        fileList.add(file);
                    }
                } catch (IOException ioe) {
                    System.err.println("error: file not readable: " + filename.substring(1));
                    errors = true;
                }
            } else {
                fileList.addAll(Arrays.asList(filenames));
            }
        }
        if (errors) {
            return null;
        } else {
            return fileList.toArray(new String[fileList.size()]);
        }
    }

    public static CompilerConfiguration generateCompilerConfigurationFromOptions(CommandLine cli) {
        //
        // Setup the configuration data

        CompilerConfiguration configuration = new CompilerConfiguration();

        if (cli.hasOption("classpath")) {
            configuration.setClasspath(cli.getOptionValue("classpath"));
        }

        if (cli.hasOption('d')) {
            configuration.setTargetDirectory(cli.getOptionValue('d'));
        }

        if (cli.hasOption("encoding")) {
            configuration.setSourceEncoding(cli.getOptionValue("encoding"));
        }

        // joint compilation parameters
        if (cli.hasOption('j')) {
            Map<String, Object> compilerOptions = new HashMap();

            String[] opts = cli.getOptionValues("J");
            compilerOptions.put("namedValues", opts);

            opts = cli.getOptionValues("F");
            compilerOptions.put("flags", opts);

            configuration.setJointCompilationOptions(compilerOptions);
        }
        return configuration;
    }

    @SuppressWarnings({"AccessStaticViaInstance"})
    public static Options createCompilationOptions() {
        //
        // Parse the command line

        Options options = new Options();

        options.addOption(OptionBuilder.hasArg().withArgName("path").withDescription("Specify where to find the class files - must be first argument").create("classpath"));
        options.addOption(OptionBuilder.withLongOpt("classpath").hasArg().withArgName("path").withDescription("Aliases for '-classpath'").create("cp"));
        options.addOption(OptionBuilder.withLongOpt("sourcepath").hasArg().withArgName("path").withDescription("Specify where to find the source files").create());
        options.addOption(OptionBuilder.withLongOpt("temp").hasArg().withArgName("temp").withDescription("Specify temporary directory").create());
        options.addOption(OptionBuilder.withLongOpt("encoding").hasArg().withArgName("encoding").withDescription("Specify the encoding of the user class files").create());
        options.addOption(OptionBuilder.hasArg().withDescription("Specify where to place generated class files").create('d'));
//            options.addOption(OptionBuilder.withLongOpt("strict").withDescription("Turn on strict type safety.").create('s'));
        options.addOption(OptionBuilder.withLongOpt("help").withDescription("Print a synopsis of standard options").create('h'));
        options.addOption(OptionBuilder.withLongOpt("version").withDescription("Print the version").create('v'));
        options.addOption(OptionBuilder.withLongOpt("exception").withDescription("Print stack trace on error").create('e'));
        options.addOption(OptionBuilder.withLongOpt("jointCompilation").withDescription("Attach javac compiler to compile .java files").create('j'));

        options.addOption(
                OptionBuilder.withArgName("property=value")
                        .withValueSeparator()
                        .hasArgs(2)
                        .withDescription("name-value pairs to pass to javac")
                        .create("J"));
        options.addOption(
                OptionBuilder.withArgName("flag")
                        .hasArg()
                        .withDescription("passed to javac for joint compilation")
                        .create("F"));
        return options;
    }

    public static File createTempDir() throws IOException {
        final int MAXTRIES = 3;
        int accessDeniedCounter = 0;
        File tempFile=null;
        for (int i=0; i<MAXTRIES; i++) {
            try {
                tempFile = File.createTempFile("groovy-generated-", "-java-source");
                tempFile.delete();
                tempFile.mkdirs();
                break;
            } catch (IOException ioe) {
                if (ioe.getMessage().startsWith("Access is denied")) {
                    accessDeniedCounter++;
                    try { Thread.sleep(100); } catch (InterruptedException e) {}
                }
                if (i==MAXTRIES-1) {
                    if (accessDeniedCounter==MAXTRIES) {
                        String msg = 
                            "Access is denied.\nWe tried " +
                            + accessDeniedCounter+
                            " times to create a temporary directory"+
                            " and failed each time. If you are on Windows"+
                            " you are possibly victim to"+
                            " http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6325169. "+
                            " this is no bug in Groovy.";
                        throw new IOException(msg);
                    } else {
                        throw ioe;
                    }
                }
                continue;
            }
        }
        return tempFile;
    }

    public static void deleteRecursive(File file) {
        if (!file.exists()) {
            return;
        }
        if (file.isFile()) {
            file.delete();
        } else if (file.isDirectory()) {
            File[] files = file.listFiles();
            for (int i = 0; i < files.length; i++) {
                deleteRecursive(files[i]);
            }
            file.delete();
        }
    }
}