Basic multi-release jar handling

bombe-jar/src/main/java/org/cadixdev/bombe/jar/AbstractJarEntry.java

@@ -32,6 +32,7 @@
 
 import java.io.IOException;
 import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
 import java.util.jar.JarOutputStream;
 
 /**
@@ -42,11 +43,44 @@
  */
 public abstract class AbstractJarEntry {
 
+    /**
+     * A {@link #getVersion()} value for jar entries that are at the base
+     * version in the jar.
+     */
+    public static final int UNVERSIONED = -1;
+
+    private static final String META_INF = "META-INF/";
+    private static final String VERSIONS_PREFIX = META_INF + "versions/";
+
     protected final String name;
     protected final long time;
+    private String unversionedName;
+    private int version = UNVERSIONED;
     private String packageName;
     private String simpleName;
 
+    /**
+     * Create a new jar entry for a specific multi-release variant.
+     *
+     * <p>If {@code unversionedName} starts with {@code META-INF}, it will be
+     * treated as being in the base version no matter what value is provided for
+     * {@code version}, to match the behavior of the JDK's {@link JarFile}.</p>
+     *
+     * @param version the Java version number to associate this entry with
+     * @param unversionedName the name without any versioned prefix
+     * @param time the time the entry was created at
+     */
+    protected AbstractJarEntry(final int version, final String unversionedName, final long time) {
+        if (version == UNVERSIONED || unversionedName.startsWith(META_INF)) {
+            this.name = unversionedName;
+        } else {
+            this.version = version;
+            this.unversionedName = unversionedName;
+            this.name = VERSIONS_PREFIX + version + '/' + unversionedName;
+        }
+        this.time = time;
+    }
+
     protected AbstractJarEntry(final String name, final long time) {
         this.name = name;
         this.time = time;
@@ -55,6 +89,8 @@ protected AbstractJarEntry(final String name, final long time) {
     /**
      * Gets the fully-qualified name of the jar entry.
      *
+     * <p>This method does not have any special handling for multi-release jars.</p>
+     *
      * @return The name
      */
     public final String getName() {
@@ -70,6 +106,48 @@ public final long getTime() {
         return this.time;
     }
 
+    /**
+     * Get the name of this entry, as it will be seen by a multi-release-aware
+     * jar handler.
+     *
+     * <p>When a file path is in the {@code META-INF/versions/} folder but does
+     * not provide a valid multi-release version, it will be treated as if it
+     * were an ordinary, un-versioned resource.</p>
+     *
+     * <p>This will always handle multi-release paths, even when the
+     * {@code Multi-Release} manifest attribute is set to false.</p>
+     *
+     * @return the full entry name, without any version prefix
+     */
+    public final String getUnversionedName() {
+        if (this.unversionedName != null) return this.unversionedName;
+
+        if (!this.name.startsWith(VERSIONS_PREFIX)) {
+            return this.unversionedName = this.name;
+        }
+        // <version number>/<path>
+        final String trimmed = this.name.substring(VERSIONS_PREFIX.length());
+        final int divider = trimmed.indexOf('/');
+        if (divider == -1) { // malformed, ignore
+            return this.unversionedName = this.name;
+        }
+
+        final String version = trimmed.substring(0, divider);
+        final String unversioned = trimmed.substring(divider + 1);
+        try {
+            if (!unversioned.startsWith(META_INF)) { // Files already within META-INF cannot be versioned
+                final int parsedVersion = Integer.parseInt(version);
+                if (parsedVersion >= 0) {
+                    this.version = parsedVersion;
+                    return this.unversionedName = unversioned;
+                }
+            }
+        } catch (final NumberFormatException ignored) { // invalid integer, treat as unversioned
+            // fall through
+        }
+        return this.unversionedName = this.name;
+    }
+
     /**
      * Gets the package that contains the jar entry, an empty
      * string if in the root package.
@@ -78,9 +156,10 @@ public final long getTime() {
      */
     public final String getPackage() {
         if (this.packageName != null) return this.packageName;
-        final int index = this.name.lastIndexOf('/');
+        final String name = this.getUnversionedName();
+        final int index = name.lastIndexOf('/');
         if (index == -1) return this.packageName = "";
-        return this.packageName = this.name.substring(0, index);
+        return this.packageName = name.substring(0, index);
     }
 
     /**
@@ -92,12 +171,28 @@ public final String getSimpleName() {
         if (this.simpleName != null) return this.simpleName;
         final int packageLength = this.getPackage().isEmpty() ? -1 : this.getPackage().length();
         final int extensionLength = this.getExtension().isEmpty() ? -1 : this.getExtension().length();
-        return this.simpleName = this.name.substring(
+        final String name = this.getUnversionedName();
+        return this.simpleName = name.substring(
                 packageLength + 1,
-                this.name.length() - (extensionLength + 1)
+                name.length() - (extensionLength + 1)
         );
     }
 
+    /**
+     * If this is a multi-release variant of a class file in a multi-release
+     * jar, the version associated with this variant.
+     *
+     * @return the version, or {@link #UNVERSIONED} if this is the base version,
+     *     or a file that would not be interpreted as a multi-release variant
+     *     within the version folder.
+     * @see #getUnversionedName() for a description of the conditions on multi-release jars
+     */
+    public int getVersion() {
+        if (this.unversionedName != null) return this.version;
+        this.getUnversionedName(); // initialize versions
+        return this.version;
+    }
+
     /**
      * Gets the extension of the jar entry.
      *
@@ -132,9 +227,9 @@ public final void write(final JarOutputStream jos) throws IOException {
     /**
      * Processes the jar entry with the given transformer.
      *
-     * @param vistor The transformer
+     * @param visitor The transformer
      * @return The jar entry
      */
-    public abstract AbstractJarEntry accept(final JarEntryTransformer vistor);
+    public abstract AbstractJarEntry accept(final JarEntryTransformer visitor);
 
 }

bombe-jar/src/main/java/org/cadixdev/bombe/jar/JarClassEntry.java

@@ -42,6 +42,11 @@ public class JarClassEntry extends AbstractJarEntry {
 
     private final byte[] contents;
 
+    public JarClassEntry(final int version, final String unversionedName, final long time, final byte[] contents) {
+        super(version, unversionedName, time);
+        this.contents = contents;
+    }
+
     public JarClassEntry(final String name, final long time, final byte[] contents) {
         super(name, time);
         this.contents = contents;
@@ -58,8 +63,8 @@ public final byte[] getContents() {
     }
 
     @Override
-    public final JarClassEntry accept(final JarEntryTransformer vistor) {
-        return vistor.transform(this);
+    public final JarClassEntry accept(final JarEntryTransformer visitor) {
+        return visitor.transform(this);
     }
 
 }

bombe-jar/src/main/java/org/cadixdev/bombe/jar/JarManifestEntry.java

@@ -78,8 +78,8 @@ public final byte[] getContents() {
     }
 
     @Override
-    public JarManifestEntry accept(final JarEntryTransformer vistor) {
-        return vistor.transform(this);
+    public JarManifestEntry accept(final JarEntryTransformer visitor) {
+        return visitor.transform(this);
     }
 
 }

bombe-jar/src/main/java/org/cadixdev/bombe/jar/JarResourceEntry.java

@@ -42,6 +42,11 @@ public class JarResourceEntry extends AbstractJarEntry {
     private final byte[] contents;
     private String extension;
 
+    public JarResourceEntry(final int version, final String unversionedName, final long time, final byte[] contents) {
+        super(version, unversionedName, time);
+        this.contents = contents;
+    }
+
     public JarResourceEntry(final String name, final long time, final byte[] contents) {
         super(name, time);
         this.contents = contents;
@@ -61,8 +66,8 @@ public final byte[] getContents() {
     }
 
     @Override
-    public final JarResourceEntry accept(final JarEntryTransformer vistor) {
-        return vistor.transform(this);
+    public final JarResourceEntry accept(final JarEntryTransformer visitor) {
+        return visitor.transform(this);
     }
 
 }

bombe-jar/src/main/java/org/cadixdev/bombe/jar/JarServiceProviderConfigurationEntry.java

@@ -79,8 +79,8 @@ public final byte[] getContents() {
     }
 
     @Override
-    public final JarServiceProviderConfigurationEntry accept(final JarEntryTransformer vistor) {
-        return vistor.transform(this);
+    public final JarServiceProviderConfigurationEntry accept(final JarEntryTransformer visitor) {
+        return visitor.transform(this);
     }
 
 }

bombe-jar/src/main/java/org/cadixdev/bombe/jar/asm/JarEntryRemappingTransformer.java

@@ -85,9 +85,9 @@ public JarClassEntry transform(final JarClassEntry entry) {
         ), 0);
 
         // Create the jar entry
-        final String originalName = entry.getName().substring(0, entry.getName().length() - ".class".length());
+        final String originalName = entry.getUnversionedName().substring(0, entry.getUnversionedName().length() - ".class".length());
         final String name = this.remapper.map(originalName) + ".class";
-        return new JarClassEntry(name, entry.getTime(), writer.toByteArray());
+        return new JarClassEntry(entry.getVersion(), name, entry.getTime(), writer.toByteArray());
     }
 
     @Override

bombe-jar/src/test/groovy/org/cadixdev/bombe/jar/test/JarEntrySpec.groovy

@@ -31,6 +31,7 @@
 package org.cadixdev.bombe.jar.test
 
 import org.cadixdev.bombe.jar.AbstractJarEntry
+import org.cadixdev.bombe.jar.JarClassEntry
 import org.cadixdev.bombe.jar.JarResourceEntry
 import spock.lang.Specification
 
@@ -41,6 +42,10 @@ class JarEntrySpec extends Specification {
 
     private static final AbstractJarEntry PACKAGED_ENTRY = new JarResourceEntry("pack/beep.boop", 0, null)
     private static final AbstractJarEntry ROOT_ENTRY = new JarResourceEntry("beep.boop", 0, null)
+    private static final AbstractJarEntry VERSION_BY_PATH = new JarClassEntry("META-INF/versions/9/module-info.class", 0, null)
+    private static final AbstractJarEntry VERSION_EXPLICIT = new JarClassEntry(11, "pack/a/b.class", 0, null)
+    private static final AbstractJarEntry VERSION_MALFORMED = new JarClassEntry("META-INF/versions/ab/module-info.class", 0, null)
+    private static final AbstractJarEntry VERSION_UNVERSIONABLE = new JarClassEntry("META-INF/versions/14/META-INF/services/a.b\$Provider", 0, null)
 
     def "reads name correctly"(final AbstractJarEntry entry,
                                final String packageName,
@@ -57,4 +62,22 @@ class JarEntrySpec extends Specification {
         ROOT_ENTRY     | ''          | 'beep'     | 'boop'
     }
 
+    def "handles multirelease paths correctly"(final AbstractJarEntry entry,
+                                                final String fullName,
+                                                final int version,
+                                                final String name) {
+        expect:
+        entry.name == fullName
+        entry.version == version
+        entry.unversionedName == name
+
+        where:
+        entry                 | fullName                                               | version                      | name
+        PACKAGED_ENTRY        | "pack/beep.boop"                                       | AbstractJarEntry.UNVERSIONED | "pack/beep.boop"
+        VERSION_BY_PATH       | "META-INF/versions/9/module-info.class"                | 9                            | "module-info.class"
+        VERSION_EXPLICIT      | "META-INF/versions/11/pack/a/b.class"                  | 11                           | "pack/a/b.class"
+        VERSION_MALFORMED     | "META-INF/versions/ab/module-info.class"               | AbstractJarEntry.UNVERSIONED | "META-INF/versions/ab/module-info.class"
+        VERSION_UNVERSIONABLE | "META-INF/versions/14/META-INF/services/a.b\$Provider" | AbstractJarEntry.UNVERSIONED | "META-INF/versions/14/META-INF/services/a.b\$Provider"
+    }
+
 }

bombe-jar/src/test/groovy/org/cadixdev/bombe/jar/test/asm/JarEntryRemappingTransformerSpec.groovy

@@ -80,6 +80,28 @@ class JarEntryRemappingTransformerSpec extends Specification {
         node.name == 'pkg/Demo'
     }
 
+    def "remaps multi-release class"() {
+        given:
+        // Create a test class
+        def obf = new ClassWriter(0)
+        obf.visit(Opcodes.V9, Opcodes.ACC_PUBLIC, 'a', null, 'java/lang/Object', null)
+
+        // Run it through the transformer
+        def entry = TRANSFORMER.transform(new JarClassEntry('META-INF/versions/9/a.class', 0, obf.toByteArray()))
+
+        // Use a ClassNode for convenience
+        def node = new ClassNode()
+        def reader = new ClassReader(entry.contents)
+        reader.accept(node, 0)
+
+        expect:
+        entry.name == 'META-INF/versions/9/pkg/Demo.class'
+        entry.version == 9
+        entry.unversionedName == 'pkg/Demo.class'
+        node.name == 'pkg/Demo'
+
+    }
+
     def "remaps manifest"() {
         given:
         // Create a test Manifest