#185 Add outputTimestamp property for reproducible builds

README.md

@@ -212,6 +212,7 @@ the _add-module-info_ goal as follows:
             <configuration>
                 <jvmVersion>11</jvmVersion>
                 <failOnWarning>false</failOnWarning>
+                <outputTimestamp>1980-01-01T00:00:02Z</outputTimestamp>
                 <module>
                     <moduleInfo>
                         <name>com.example</name>
@@ -242,6 +243,11 @@ The special value `base` (the default) can be used to add the descriptor to the
 Putting the descriptor under `META-INF/versions` can help to increase compatibility with older libraries scanning class files that may fail when encountering the `module-info.class` file
 (as chances are lower that such tool will look for class files under `META-INF/versions/...`).
 
+The optional `outputTimestamp` element may be used to create reproducible output archive entries, either formatted as 
+ISO 8601 extended offset date-time (e.g. in UTC such as '2011-12-03T10:15:30Z' or with an offset '2019-10-05T20:37:42+06:00'),
+or as an int representing seconds since the epoch. As an alternative you may set `${project.build.outputTimestamp}` which also
+matches the user property used by other Maven plugins such as `maven-jar-plugin`.
+
 The optional `failOnWarning` option prevents the build from failing when set to `false`. The default is to fail.
 
 The optional `exclusions` option may be used to filter out any `compile` or `runtime` dependencies that should not be used, as it might be the case when shading internal dependencies.

core/src/main/java/org/moditect/Moditect.java

@@ -17,6 +17,12 @@
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.text.NumberFormat;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeParseException;
+import java.time.temporal.ChronoUnit;
 
 import org.moditect.commands.AddModuleInfo;
 
@@ -31,7 +37,7 @@ public static void main(String[] args) throws Exception {
         CliArgs cliArgs = new CliArgs();
         new JCommander( cliArgs, args );
 
-        new AddModuleInfo( null, null, null, null, cliArgs.outputDirecory, cliArgs.jvmVersion, cliArgs.overwriteExistingFiles ).run();
+        new AddModuleInfo( null, null, null, null, cliArgs.outputDirecory, cliArgs.jvmVersion, cliArgs.overwriteExistingFiles, cliArgs.timestamp ).run();
     }
 
     @Parameters(separators = "=")
@@ -67,6 +73,14 @@ private static class CliArgs {
                 description = "Whether to overwrite existing files or not"
         )
         private boolean overwriteExistingFiles;
+
+        @Parameter(
+            names = "--timestamp",
+            required = false,
+            description = "Timestamp used when writing archive entries",
+            converter = InstantConverter.class
+        )
+        private Instant timestamp;
     }
 
     private static class PathConverter implements IStringConverter<Path> {
@@ -76,4 +90,47 @@ public Path convert(String value) {
             return Paths.get( value );
         }
     }
+
+    private static class InstantConverter implements IStringConverter<Instant> {
+
+        private static final Instant DATE_MIN = Instant.parse( "1980-01-01T00:00:02Z" );
+        private static final Instant DATE_MAX = Instant.parse( "2099-12-31T23:59:59Z" );
+
+        @Override
+        public Instant convert(String value) {
+            if ( value == null ) {
+                return null;
+            }
+
+            // Number representing seconds since the epoch
+            if ( !value.isEmpty() && isNumeric( value ) ) {
+                return Instant.ofEpochSecond( Long.parseLong( value.trim() ) );
+            }
+
+            try {
+                // Parse the date in UTC such as '2011-12-03T10:15:30Z' or with an offset '2019-10-05T20:37:42+06:00'.
+                final Instant date = OffsetDateTime.parse( value )
+                    .withOffsetSameInstant( ZoneOffset.UTC ).truncatedTo( ChronoUnit.SECONDS ).toInstant();
+
+                if ( date.isBefore( DATE_MIN ) || date.isAfter( DATE_MAX ) ) {
+                    throw new IllegalArgumentException( "'" + date + "' is not within the valid range "
+                        + DATE_MIN + " to " + DATE_MAX );
+                }
+                return date;
+            }
+            catch ( DateTimeParseException pe ) {
+                throw new IllegalArgumentException( "Invalid project.build.outputTimestamp value '" + value + "'",
+                    pe );
+            }
+        }
+
+        private boolean isNumeric( String str ) {
+            try {
+                Long.parseLong( str.trim() );
+                return true;
+            } catch( NumberFormatException e ) {
+                return false;
+            }
+        }
+    }
 }

core/src/main/java/org/moditect/commands/AddModuleInfo.java

@@ -24,6 +24,8 @@
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.jar.Attributes;
@@ -49,16 +51,17 @@ public class AddModuleInfo {
     private final Path outputDirectory;
     private final Integer jvmVersion;
     private final boolean overwriteExistingFiles;
+    private final Instant timestamp;
 
-    public AddModuleInfo(String moduleInfoSource, String mainClass, String version, Path inputJar, Path outputDirectory, String jvmVersion, boolean overwriteExistingFiles) {
+    public AddModuleInfo(String moduleInfoSource, String mainClass, String version, Path inputJar, Path outputDirectory, String jvmVersion, boolean overwriteExistingFiles, Instant timestamp) {
         this.moduleInfoSource = moduleInfoSource;
         this.mainClass = mainClass;
         this.version = version;
         this.inputJar = inputJar;
         this.outputDirectory = outputDirectory;
 
         // #67 It'd be nice to use META-INF/services/9 by default to avoid conflicts with legacy
-        // classpath scanners, but this causes isses with subsequent jdeps invocations if there
+        // classpath scanners, but this causes issues with subsequent jdeps invocations if there
         // are MR-JARs and non-MR JARs passed to it due to https://bugs.openjdk.java.net/browse/JDK-8207162
         if (jvmVersion == null || jvmVersion.equals(NO_JVM_VERSION)) {
             this.jvmVersion = null;
@@ -75,6 +78,7 @@ public AddModuleInfo(String moduleInfoSource, String mainClass, String version,
             }
         }
         this.overwriteExistingFiles = overwriteExistingFiles;
+        this.timestamp = timestamp;
     }
 
     public void run() {
@@ -105,14 +109,16 @@ public void run() {
 
         Map<String, String> env = new HashMap<>();
         env.put( "create", "true" );
-        URI uri = URI.create( "jar:" + outputJar.toUri().toString() );
+        URI uri = URI.create( "jar:" + outputJar.toUri() );
 
        try (FileSystem zipfs = FileSystems.newFileSystem( uri, env ) ) {
            if (jvmVersion == null) {
-               Files.write( zipfs.getPath( "module-info.class" ), clazz,
+               Path path = zipfs.getPath("module-info.class");
+               Files.write(path, clazz,
                  StandardOpenOption.CREATE,
                  StandardOpenOption.WRITE,
                  StandardOpenOption.TRUNCATE_EXISTING );
+               Files.setLastModifiedTime( path, toFileTime(timestamp) );
            }
            else {
                Path path = zipfs.getPath( "META-INF/versions", jvmVersion.toString(), "module-info.class" );
@@ -121,6 +127,13 @@ public void run() {
                  StandardOpenOption.CREATE,
                  StandardOpenOption.WRITE,
                  StandardOpenOption.TRUNCATE_EXISTING );
+               FileTime lastModifiedTime = toFileTime( timestamp );
+               // module-info.class
+               Files.setLastModifiedTime( path, lastModifiedTime );
+               // jvmVersion
+               Files.setLastModifiedTime( path.getParent(), lastModifiedTime );
+               // versions
+               Files.setLastModifiedTime( path.getParent().getParent(), lastModifiedTime );
 
                Path manifestPath = zipfs.getPath( "META-INF/MANIFEST.MF" );
                Manifest manifest;
@@ -136,10 +149,15 @@ public void run() {
                try (OutputStream manifestOs = Files.newOutputStream( manifestPath, StandardOpenOption.TRUNCATE_EXISTING )) {
                    manifest.write( manifestOs );
                }
+               Files.setLastModifiedTime( manifestPath, lastModifiedTime );
            }
        }
        catch(IOException e) {
             throw new RuntimeException( "Couldn't add module-info.class to JAR", e );
         }
     }
+
+    private FileTime toFileTime( Instant timestamp ) {
+        return FileTime.from( timestamp != null ? timestamp : Instant.now() );
+    }
 }

core/src/test/java/org/moditect/test/AddModuleInfoTest.java

@@ -99,7 +99,8 @@ public void addJvmVersionModuleInfoAndRunModular() throws Exception {
                 Paths.get( "target", "generated-test-resources", "example.jar" ),
                 Paths.get( "target", "generated-test-modules" ),
                 "9",
-                false
+                false,
+            null
         )
         .run();
 
@@ -144,7 +145,8 @@ public void addModuleInfoAndRunModular() throws Exception {
             Paths.get( "target", "generated-test-resources", "example.jar" ),
             Paths.get( "target", "generated-test-modules" ),
             null,
-            false
+            false,
+            null
         )
         .run();
 

maven-plugin/src/main/java/org/moditect/mavenplugin/add/AddModuleInfoMojo.java

@@ -20,6 +20,11 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.StandardCopyOption;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeParseException;
+import java.time.temporal.ChronoUnit;
 import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.HashMap;
@@ -108,6 +113,15 @@ public class AddModuleInfoMojo extends AbstractMojo {
     @Parameter(property = "overwriteExistingFiles", defaultValue = "false")
     private boolean overwriteExistingFiles;
 
+    /**
+     * Timestamp for reproducible output archive entries, either formatted as ISO 8601 extended offset date-time
+     * (e.g. in UTC such as '2011-12-03T10:15:30Z' or with an offset '2019-10-05T20:37:42+06:00'),
+     * or as an int representing seconds since the epoch
+     * (like <a href="https://reproducible-builds.org/docs/source-date-epoch/">SOURCE_DATE_EPOCH</a>).
+     */
+    @Parameter(defaultValue = "${project.build.outputTimestamp}")
+    private String outputTimestamp;
+
     @Parameter(property = "moditect.skip", defaultValue = "false")
     private boolean skip;
 
@@ -183,7 +197,8 @@ project, repoSystem, repoSession, remoteRepos, artifactResolutionHelper, jdepsEx
                     inputFile,
                     outputPath,
                     jvmVersion,
-                    overwriteExistingFiles
+                    overwriteExistingFiles,
+                    InstantConverter.convert(outputTimestamp)
                 );
 
                 addModuleInfo.run();
@@ -220,7 +235,8 @@ project, repoSystem, repoSession, remoteRepos, artifactResolutionHelper, jdepsEx
                     inputJar,
                     outputPath,
                     jvmVersion,
-                    overwriteExistingFiles
+                    overwriteExistingFiles,
+                    InstantConverter.convert(outputTimestamp)
             );
             addModuleInfo.run();
 
@@ -485,4 +501,47 @@ private String getAssignedModuleName(Map<ArtifactIdentifier, String> assignedNam
 
         return null;
     }
+
+
+    private static class InstantConverter {
+
+        private static final Instant DATE_MIN = Instant.parse( "1980-01-01T00:00:02Z" );
+        private static final Instant DATE_MAX = Instant.parse( "2099-12-31T23:59:59Z" );
+
+        public static Instant convert(String value) {
+            if ( value == null ) {
+                return null;
+            }
+
+            // Number representing seconds since the epoch
+            if ( !value.isEmpty() && isNumeric( value ) ) {
+                return Instant.ofEpochSecond( Long.parseLong( value.trim() ) );
+            }
+
+            try {
+                // Parse the date in UTC such as '2011-12-03T10:15:30Z' or with an offset '2019-10-05T20:37:42+06:00'.
+                final Instant date = OffsetDateTime.parse( value )
+                    .withOffsetSameInstant( ZoneOffset.UTC ).truncatedTo( ChronoUnit.SECONDS ).toInstant();
+
+                if ( date.isBefore( DATE_MIN ) || date.isAfter( DATE_MAX ) ) {
+                    throw new IllegalArgumentException( "'" + date + "' is not within the valid range "
+                        + DATE_MIN + " to " + DATE_MAX );
+                }
+                return date;
+            }
+            catch ( DateTimeParseException pe ) {
+                throw new IllegalArgumentException( "Invalid project.build.outputTimestamp value '" + value + "'",
+                    pe );
+            }
+        }
+
+        private static boolean isNumeric( String str ) {
+            try {
+                Long.parseLong( str.trim() );
+                return true;
+            } catch( NumberFormatException e ) {
+                return false;
+            }
+        }
+    }
 }