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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.internal.module;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.module.ModuleDescriptor.Version;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import jdk.internal.org.objectweb.asm.Attribute;
import jdk.internal.org.objectweb.asm.ClassReader;
import jdk.internal.org.objectweb.asm.ClassVisitor;
import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.ModuleVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;
import jdk.internal.org.objectweb.asm.commons.ModuleHashesAttribute;
import jdk.internal.org.objectweb.asm.commons.ModuleResolutionAttribute;
import jdk.internal.org.objectweb.asm.commons.ModuleTargetAttribute;

Utility class to extend a module-info.class with additional attributes.
/** * Utility class to extend a module-info.class with additional attributes. */
public final class ModuleInfoExtender { // the input stream to read the original module-info.class private final InputStream in; // the packages in the ModulePackages attribute private Set<String> packages; // the value for the module version in the Module attribute private Version version; // the value of the ModuleMainClass attribute private String mainClass; // the value for the ModuleTarget attribute private String targetPlatform; // the hashes for the ModuleHashes attribute private ModuleHashes hashes; // the value of the ModuleResolution attribute private ModuleResolution moduleResolution; private ModuleInfoExtender(InputStream in) { this.in = in; }
Sets the packages for the ModulePackages attribute
API Note:This method does not check that the package names are legal package names or that the set of packages is a super set of the packages in the module.
/** * Sets the packages for the ModulePackages attribute * * @apiNote This method does not check that the package names are legal * package names or that the set of packages is a super set of the * packages in the module. */
public ModuleInfoExtender packages(Set<String> packages) { this.packages = Collections.unmodifiableSet(packages); return this; }
Sets the value for the module version in the Module attribute
/** * Sets the value for the module version in the Module attribute */
public ModuleInfoExtender version(Version version) { this.version = version; return this; }
Sets the value of the ModuleMainClass attribute.
API Note:This method does not check that the main class is a legal class name in a named package.
/** * Sets the value of the ModuleMainClass attribute. * * @apiNote This method does not check that the main class is a legal * class name in a named package. */
public ModuleInfoExtender mainClass(String mainClass) { this.mainClass = mainClass; return this; }
Sets the value for the ModuleTarget attribute.
/** * Sets the value for the ModuleTarget attribute. */
public ModuleInfoExtender targetPlatform(String targetPlatform) { this.targetPlatform = targetPlatform; return this; }
The ModuleHashes attribute will be emitted to the module-info with the hashes encapsulated in the given ModuleHashes object.
/** * The ModuleHashes attribute will be emitted to the module-info with * the hashes encapsulated in the given {@code ModuleHashes} * object. */
public ModuleInfoExtender hashes(ModuleHashes hashes) { this.hashes = hashes; return this; }
Sets the value for the ModuleResolution attribute.
/** * Sets the value for the ModuleResolution attribute. */
public ModuleInfoExtender moduleResolution(ModuleResolution mres) { this.moduleResolution = mres; return this; }
Outputs the modified module-info.class to the given output stream. Once this method has been called then the Extender object should be discarded.
/** * Outputs the modified module-info.class to the given output stream. * Once this method has been called then the Extender object should * be discarded. */
public void write(OutputStream out) throws IOException { // emit to the output stream out.write(toByteArray()); }
Returns the bytes of the modified module-info.class. Once this method has been called then the Extender object should be discarded.
/** * Returns the bytes of the modified module-info.class. * Once this method has been called then the Extender object should * be discarded. */
public byte[] toByteArray() throws IOException { ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); ClassReader cr = new ClassReader(in); ClassVisitor cv = new ClassVisitor(Opcodes.ASM7, cw) { @Override public ModuleVisitor visitModule(String name, int flags, String version) { Version v = ModuleInfoExtender.this.version; String vs = (v != null) ? v.toString() : version; ModuleVisitor mv = super.visitModule(name, flags, vs); // ModuleMainClass attribute if (mainClass != null) { mv.visitMainClass(mainClass.replace('.', '/')); } // ModulePackages attribute if (packages != null) { packages.stream() .sorted() .forEach(pn -> mv.visitPackage(pn.replace('.', '/'))); } return new ModuleVisitor(Opcodes.ASM7, mv) { public void visitMainClass(String existingMainClass) { // skip main class if there is a new value if (mainClass == null) { super.visitMainClass(existingMainClass); } } public void visitPackage(String existingPackage) { // skip packages if there is a new set of packages if (packages == null) { super.visitPackage(existingPackage); } } }; } @Override public void visitAttribute(Attribute attr) { String name = attr.type; // drop existing attributes if there are replacements if (name.equals(ClassFileConstants.MODULE_TARGET) && targetPlatform != null) return; if (name.equals(ClassFileConstants.MODULE_RESOLUTION) && moduleResolution != null) return; if (name.equals(ClassFileConstants.MODULE_HASHES) && hashes != null) return; super.visitAttribute(attr); } }; List<Attribute> attrs = new ArrayList<>(); attrs.add(new ModuleTargetAttribute()); attrs.add(new ModuleResolutionAttribute()); attrs.add(new ModuleHashesAttribute()); cr.accept(cv, attrs.toArray(new Attribute[0]), 0); // add ModuleTarget, ModuleResolution and ModuleHashes attributes if (targetPlatform != null) { cw.visitAttribute(new ModuleTargetAttribute(targetPlatform)); } if (moduleResolution != null) { int flags = moduleResolution.value(); cw.visitAttribute(new ModuleResolutionAttribute(flags)); } if (hashes != null) { String algorithm = hashes.algorithm(); List<String> names = new ArrayList<>(); List<byte[]> values = new ArrayList<>(); for (String name : hashes.names()) { names.add(name); values.add(hashes.hashFor(name)); } cw.visitAttribute(new ModuleHashesAttribute(algorithm, names, values)); } return cw.toByteArray(); }
Returns an Extender that may be used to add additional attributes to the module-info.class read from the given input stream.
/** * Returns an {@code Extender} that may be used to add additional * attributes to the module-info.class read from the given input * stream. */
public static ModuleInfoExtender newExtender(InputStream in) { return new ModuleInfoExtender(in); } }