1 /*

     2  * Copyright (c) 2017, 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 java.io.InputStream;

    25 import java.io.IOException;

    26 import java.lang.module.ModuleReader;

    27 import java.lang.module.ModuleReference;

    28 import java.net.URI;

    29 import java.nio.file.Files;

    30 import java.nio.file.Path;

    31 import java.nio.file.Paths;

    32 

    33 import jdk.internal.module.ModuleInfo;

    34 import jdk.internal.module.ModuleInfo.Attributes;

    35 

    36 public class ModuleTargetHelper {

    37     private ModuleTargetHelper() {}

    38 

    39     public static final class ModuleTarget {

    40         private String targetPlatform;

    41 

    42         public ModuleTarget(String targetPlatform) {

    43             this.targetPlatform = targetPlatform;

    44         }

    45 

    46         public String targetPlatform() {

    47             return targetPlatform;

    48         }

    49     }

    50 

    51     public static ModuleTarget getJavaBaseTarget() throws IOException {

    52         Path p = Paths.get(URI.create("jrt:/modules/java.base/module-info.class"));

    53         try (InputStream in = Files.newInputStream(p)) {

    54             return read(in);

    55         }

    56     }

    57 

    58     public static ModuleTarget read(InputStream in) throws IOException {

    59         ModuleInfo.Attributes attrs = ModuleInfo.read(in, null);

    60         if (attrs.target() != null) {

    61             return new ModuleTarget(attrs.target().targetPlatform());

    62         } else {

    63             return null;

    64         }

    65     }

    66 

    67     public static ModuleTarget read(ModuleReference modRef) throws IOException {

    68         ModuleReader reader = modRef.open();

    69         try (InputStream in = reader.open("module-info.class").get()) {

    70             return read(in);

    71         } finally {

    72             reader.close();

    73         }

    74     }

    75 }