obfuscator.java

ProGuard 是一个免费的 Java类文件的压缩

                    new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                    new MemberNameCollector(configuration.overloadAggressively,
                                                descriptorMap)))),

                    // Assign new names to all non-private members in this class.
                    new AllMemberVisitor(
                    new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                    new MemberObfuscator(configuration.overloadAggressively,
                                         nameFactory,
                                         descriptorMap))),

                    // Clear the collected names.
                    new MapCleaner(descriptorMap)
                }));

            // Come up with new names for all private class members.
            programClassPool.classesAccept(
                new MultiClassVisitor(new ClassVisitor[]
                {
                    // Collect all member names in this class.
                    new AllMemberVisitor(
                    new MemberNameCollector(configuration.overloadAggressively,
                                            descriptorMap)),

                    // Collect all non-private member names higher up the hierarchy.
                    new ClassHierarchyTraveler(false, true, true, false,
                    new AllMemberVisitor(
                    new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                    new MemberNameCollector(configuration.overloadAggressively,
                                            descriptorMap)))),

                    // Assign new names to all private members in this class.
                    new AllMemberVisitor(
                    new MemberAccessFilter(ClassConstants.INTERNAL_ACC_PRIVATE, 0,
                    new MemberObfuscator(configuration.overloadAggressively,
                                         nameFactory,
                                         descriptorMap))),

                    // Clear the collected names.
                    new MapCleaner(descriptorMap)
                }));
        }

        // Some class members may have ended up with conflicting names.
        // Come up with new, globally unique names for them.
        NameFactory specialNameFactory =
            new SpecialNameFactory(new SimpleNameFactory());

        // Collect a map of special names to avoid
        // [descriptor - new name - old name].
        Map specialDescriptorMap = new HashMap();

        programClassPool.classesAccept(
            new AllMemberVisitor(
            new MemberSpecialNameFilter(
            new MemberNameCollector(configuration.overloadAggressively,
                                    specialDescriptorMap))));

        libraryClassPool.classesAccept(
            new AllMemberVisitor(
            new MemberSpecialNameFilter(
            new MemberNameCollector(configuration.overloadAggressively,
                                    specialDescriptorMap))));

        // Replace conflicting non-private member names with special names.
        programClassPool.classesAccept(
            new MultiClassVisitor(new ClassVisitor[]
            {
                // Collect all private member names in this class and down
                // the hierarchy.
                new ClassHierarchyTraveler(true, false, false, true,
                new AllMemberVisitor(
                new MemberAccessFilter(ClassConstants.INTERNAL_ACC_PRIVATE, 0,
                new MemberNameCollector(configuration.overloadAggressively,
                                        descriptorMap)))),

                // Collect all non-private member names anywhere in the hierarchy.
                new ClassHierarchyTraveler(true, true, true, true,
                new AllMemberVisitor(
                new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                new MemberNameCollector(configuration.overloadAggressively,
                                        descriptorMap)))),

                // Assign new names to all conflicting non-private members in
                // this class.
                new AllMemberVisitor(
                new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                new MemberNameConflictFixer(configuration.overloadAggressively,
                                            descriptorMap,
                                            warningPrinter,
                new MemberObfuscator(configuration.overloadAggressively,
                                     specialNameFactory,
                                     specialDescriptorMap)))),

                // Clear the collected names.
                new MapCleaner(descriptorMap)
            }));

        // Replace conflicting private member names with special names.
        // This is only possible if those names were kept or mapped.
        programClassPool.classesAccept(
            new MultiClassVisitor(new ClassVisitor[]
            {
                // Collect all member names in this class.
                new AllMemberVisitor(
                new MemberNameCollector(configuration.overloadAggressively,
                                        descriptorMap)),

                // Collect all non-private member names higher up the hierarchy.
                new ClassHierarchyTraveler(false, true, true, false,
                new AllMemberVisitor(
                new MemberAccessFilter(0, ClassConstants.INTERNAL_ACC_PRIVATE,
                new MemberNameCollector(configuration.overloadAggressively,
                                        descriptorMap)))),

                // Assign new names to all conflicting private members in this
                // class.
                new AllMemberVisitor(
                new MemberAccessFilter(ClassConstants.INTERNAL_ACC_PRIVATE, 0,
                new MemberNameConflictFixer(configuration.overloadAggressively,
                                            descriptorMap,
                                            warningPrinter,
                new MemberObfuscator(configuration.overloadAggressively,
                                     specialNameFactory,
                                     specialDescriptorMap)))),

                // Clear the collected names.
                new MapCleaner(descriptorMap)
            }));

        // Print out any warnings about member name conflicts.
        if (configuration.warn)
        {
            int warningCount = warningPrinter.getWarningCount();
            if (warningCount > 0)
            {
                System.err.println("Warning: there were " + warningCount +
                                   " conflicting class member name mappings.");
                System.err.println("         Your configuration may be inconsistent.");

                if (!configuration.ignoreWarnings)
                {
                    System.err.println("         If you are sure the conflicts are harmless,");
                    System.err.println("         you could try your luck using the '-ignorewarnings' option.");
                    throw new IOException("Please correct the above warnings first.");
                }
            }
        }

        // Print out the mapping, if requested.
        if (configuration.printMapping != null)
        {
            PrintStream ps = isFile(configuration.printMapping) ?
                new PrintStream(new BufferedOutputStream(new FileOutputStream(configuration.printMapping))) :
                System.out;

            // Print out items that will be removed.
            programClassPool.classesAcceptAlphabetically(new MappingPrinter(ps));

            if (ps != System.out)
            {
                ps.close();
            }
        }

        // Actually apply the new names.
        programClassPool.classesAccept(new ClassRenamer());
        libraryClassPool.classesAccept(new ClassRenamer());

        // Update all references to these new names.
        programClassPool.classesAccept(new ClassReferenceFixer(false));
        libraryClassPool.classesAccept(new ClassReferenceFixer(false));
        programClassPool.classesAccept(new MemberReferenceFixer());

        // Make package visible elements public or protected, if necessary.
        if (configuration.repackageClasses != null)
        {
            programClassPool.classesAccept(
                new AllConstantVisitor(
                new ClassOpener()));
        }

        // Rename the source file attributes, if requested.
        if (configuration.newSourceFileAttribute != null)
        {
            programClassPool.classesAccept(new SourceFileRenamer(configuration.newSourceFileAttribute));
        }

        // Mark NameAndType constant pool entries that have to be kept
        // and remove the other ones.
        programClassPool.classesAccept(new NameAndTypeUsageMarker());
        programClassPool.classesAccept(new NameAndTypeShrinker());

        // Mark Utf8 constant pool entries that have to be kept
        // and remove the other ones.
        programClassPool.classesAccept(new Utf8UsageMarker());
        programClassPool.classesAccept(new Utf8Shrinker());
    }


    /**
     * Returns whether the given file is actually a file, or just a placeholder
     * for the standard output.
     */
    private boolean isFile(File file)
    {
        return file.getPath().length() > 0;
    }
}