1 /*

     2  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 import javax.tools.JavaCompiler;

    25 import javax.tools.StandardJavaFileManager;

    26 import javax.tools.StandardLocation;

    27 import javax.tools.ToolProvider;

    28 import java.io.IOException;

    29 import java.nio.file.Files;

    30 import java.nio.file.Path;

    31 import java.util.Arrays;

    32 import java.util.Collections;

    33 import java.util.List;

    34 import java.util.stream.Collectors;

    35 

    36 /**

    37  * This class consists exclusively of static utility methods for invoking the

    38  * java compiler.

    39  */

    40 

    41 public final class CompilerUtils {

    42     private CompilerUtils() { }

    43 

    44     /**

    45      * Compile all the java sources in {@code <source>/**} to

    46      * {@code <destination>/**}. The destination directory will be created if

    47      * it doesn't exist.

    48      *

    49      * All warnings/errors emitted by the compiler are output to System.out/err.

    50      *

    51      * @return true if the compilation is successful

    52      *

    53      * @throws IOException

    54      *         if there is an I/O error scanning the source tree or

    55      *         creating the destination directory

    56      * @throws UnsupportedOperationException

    57      *         if there is no system java compiler

    58      */

    59     public static boolean compile(Path source, Path destination, String ... options)

    60         throws IOException

    61     {

    62         JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

    63         if (compiler == null) {

    64             // no compiler available

    65             throw new UnsupportedOperationException("Unable to get system java compiler. " +

    66                 "Perhaps, jdk.compiler module is not available.");

    67         }

    68         StandardJavaFileManager jfm = compiler.getStandardFileManager(null, null, null);

    69 

    70         List<Path> sources

    71             = Files.find(source, Integer.MAX_VALUE,

    72                 (file, attrs) -> (file.toString().endsWith(".java")))

    73                 .collect(Collectors.toList());

    74 

    75         Files.createDirectories(destination);

    76         jfm.setLocation(StandardLocation.CLASS_PATH, Collections.EMPTY_LIST);

    77         jfm.setLocationFromPaths(StandardLocation.CLASS_OUTPUT,

    78                                  Arrays.asList(destination));

    79 

    80         List<String> opts = Arrays.asList(options);

    81         JavaCompiler.CompilationTask task

    82             = compiler.getTask(null, jfm, null, opts, null,

    83                 jfm.getJavaFileObjectsFromPaths(sources));

    84 

    85         return task.call();

    86     }

    87 }