programclassreader.java

ProGuard 是一个免费的 Java类文件的压缩

    public void visitMoreZeroFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, MoreZeroFrame moreZeroFrame)
    {
        moreZeroFrame.u2offsetDelta = dataInput.readUnsignedShort();

        // Read the verification types of the additional local variables.
        moreZeroFrame.additionalVariables = new VerificationType[moreZeroFrame.additionalVariablesCount];
        for (int index = 0; index < moreZeroFrame.additionalVariablesCount; index++)
        {
            VerificationType verificationType = createVerificationType();
            verificationType.accept(clazz, method, codeAttribute, offset, this);
            moreZeroFrame.additionalVariables[index] = verificationType;
        }
    }


    public void visitFullFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, FullFrame fullFrame)
    {
        fullFrame.u2offsetDelta = dataInput.readUnsignedShort();

        // Read the verification types of the local variables.
        fullFrame.variablesCount = dataInput.readUnsignedShort();
        fullFrame.variables = new VerificationType[fullFrame.variablesCount];
        for (int index = 0; index < fullFrame.variablesCount; index++)
        {
            VerificationType verificationType = createVerificationType();
            verificationType.variablesAccept(clazz, method, codeAttribute, offset, index, this);
            fullFrame.variables[index] = verificationType;
        }

        // Read the verification types of the stack entries.
        fullFrame.stackCount = dataInput.readUnsignedShort();
        fullFrame.stack = new VerificationType[fullFrame.stackCount];
        for (int index = 0; index < fullFrame.stackCount; index++)
        {
            VerificationType verificationType = createVerificationType();
            verificationType.stackAccept(clazz, method, codeAttribute, offset, index, this);
            fullFrame.stack[index] = verificationType;
        }
    }


    // Implementations for VerificationTypeVisitor.

    public void visitAnyVerificationType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VerificationType verificationType)
    {
        // Most verification types don't contain any additional information.
    }


    public void visitObjectType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ObjectType objectType)
    {
        objectType.u2classIndex = dataInput.readUnsignedShort();
    }


    public void visitUninitializedType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, UninitializedType uninitializedType)
    {
        uninitializedType.u2newInstructionOffset = dataInput.readUnsignedShort();
    }


    // Implementations for LineNumberInfoVisitor.

    public void visitLineNumberInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberInfo lineNumberInfo)
    {
        lineNumberInfo.u2startPC    = dataInput.readUnsignedShort();
        lineNumberInfo.u2lineNumber = dataInput.readUnsignedShort();
    }


    // Implementations for LocalVariableInfoVisitor.

    public void visitLocalVariableInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableInfo localVariableInfo)
    {
        localVariableInfo.u2startPC         = dataInput.readUnsignedShort();
        localVariableInfo.u2length          = dataInput.readUnsignedShort();
        localVariableInfo.u2nameIndex       = dataInput.readUnsignedShort();
        localVariableInfo.u2descriptorIndex = dataInput.readUnsignedShort();
        localVariableInfo.u2index           = dataInput.readUnsignedShort();
    }


    // Implementations for LocalVariableTypeInfoVisitor.

    public void visitLocalVariableTypeInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeInfo localVariableTypeInfo)
    {
        localVariableTypeInfo.u2startPC        = dataInput.readUnsignedShort();
        localVariableTypeInfo.u2length         = dataInput.readUnsignedShort();
        localVariableTypeInfo.u2nameIndex      = dataInput.readUnsignedShort();
        localVariableTypeInfo.u2signatureIndex = dataInput.readUnsignedShort();
        localVariableTypeInfo.u2index          = dataInput.readUnsignedShort();
    }


    // Implementations for AnnotationVisitor.

    public void visitAnnotation(Clazz clazz, Annotation annotation)
    {
        // Read the annotation type.
        annotation.u2typeIndex = dataInput.readUnsignedShort();

        // Read the element value pairs.
        annotation.u2elementValuesCount = dataInput.readUnsignedShort();

        annotation.elementValues = new ElementValue[annotation.u2elementValuesCount];
        for (int index = 0; index < annotation.u2elementValuesCount; index++)
        {
            int u2elementNameIndex = dataInput.readUnsignedShort();
            ElementValue elementValue = createElementValue();
            elementValue.u2elementNameIndex = u2elementNameIndex;
            elementValue.accept(clazz, annotation, this);
            annotation.elementValues[index] = elementValue;
        }
    }


    // Implementations for ElementValueVisitor.

    public void visitConstantElementValue(Clazz clazz, Annotation annotation, ConstantElementValue constantElementValue)
    {
        constantElementValue.u2constantValueIndex = dataInput.readUnsignedShort();
    }


    public void visitEnumConstantElementValue(Clazz clazz, Annotation annotation, EnumConstantElementValue enumConstantElementValue)
    {
        enumConstantElementValue.u2typeNameIndex     = dataInput.readUnsignedShort();
        enumConstantElementValue.u2constantNameIndex = dataInput.readUnsignedShort();
    }


    public void visitClassElementValue(Clazz clazz, Annotation annotation, ClassElementValue classElementValue)
    {
        classElementValue.u2classInfoIndex = dataInput.readUnsignedShort();
    }


    public void visitAnnotationElementValue(Clazz clazz, Annotation annotation, AnnotationElementValue annotationElementValue)
    {
        // Read the annotation.
        Annotation annotationValue = new Annotation();
        this.visitAnnotation(clazz, annotationValue);
        annotationElementValue.annotationValue = annotationValue;
    }


    public void visitArrayElementValue(Clazz clazz, Annotation annotation, ArrayElementValue arrayElementValue)
    {
        // Read the element values.
        arrayElementValue.u2elementValuesCount = dataInput.readUnsignedShort();

        arrayElementValue.elementValues = new ElementValue[arrayElementValue.u2elementValuesCount];
        for (int index = 0; index < arrayElementValue.u2elementValuesCount; index++)
        {
            ElementValue elementValue = createElementValue();
            elementValue.accept(clazz, annotation, this);
            arrayElementValue.elementValues[index] = elementValue;
        }
    }


    // Small utility methods.

    private Constant createConstant()
    {
        int u1tag = dataInput.readUnsignedByte();

        switch (u1tag)
        {
            case ClassConstants.CONSTANT_Utf8:               return new Utf8Constant();
            case ClassConstants.CONSTANT_Integer:            return new IntegerConstant();
            case ClassConstants.CONSTANT_Float:              return new FloatConstant();
            case ClassConstants.CONSTANT_Long:               return new LongConstant();
            case ClassConstants.CONSTANT_Double:             return new DoubleConstant();
            case ClassConstants.CONSTANT_String:             return new StringConstant();
            case ClassConstants.CONSTANT_Fieldref:           return new FieldrefConstant();
            case ClassConstants.CONSTANT_Methodref:          return new MethodrefConstant();
            case ClassConstants.CONSTANT_InterfaceMethodref: return new InterfaceMethodrefConstant();
            case ClassConstants.CONSTANT_Class:              return new ClassConstant();
            case ClassConstants.CONSTANT_NameAndType:        return new NameAndTypeConstant();

            default: throw new RuntimeException("Unknown constant type ["+u1tag+"] in constant pool");
        }
    }


    private Attribute createAttribute(Clazz clazz)
    {
        int u2attributeNameIndex = dataInput.readUnsignedShort();
        int u4attributeLength    = dataInput.readInt();
        String attributeName     = clazz.getString(u2attributeNameIndex);
        Attribute attribute =
            attributeName.equals(ClassConstants.ATTR_SourceFile)                           ? (Attribute)new SourceFileAttribute():
            attributeName.equals(ClassConstants.ATTR_SourceDir)                            ? (Attribute)new SourceDirAttribute():
            attributeName.equals(ClassConstants.ATTR_InnerClasses)                         ? (Attribute)new InnerClassesAttribute():
            attributeName.equals(ClassConstants.ATTR_EnclosingMethod)                      ? (Attribute)new EnclosingMethodAttribute():
            attributeName.equals(ClassConstants.ATTR_Deprecated)                           ? (Attribute)new DeprecatedAttribute():
            attributeName.equals(ClassConstants.ATTR_Synthetic)                            ? (Attribute)new SyntheticAttribute():
            attributeName.equals(ClassConstants.ATTR_Signature)                            ? (Attribute)new SignatureAttribute():
            attributeName.equals(ClassConstants.ATTR_ConstantValue)                        ? (Attribute)new ConstantValueAttribute():
            attributeName.equals(ClassConstants.ATTR_Exceptions)                           ? (Attribute)new ExceptionsAttribute():
            attributeName.equals(ClassConstants.ATTR_Code)                                 ? (Attribute)new CodeAttribute():
            attributeName.equals(ClassConstants.ATTR_StackMap)                             ? (Attribute)new StackMapAttribute():
            attributeName.equals(ClassConstants.ATTR_StackMapTable)                        ? (Attribute)new StackMapTableAttribute():
            attributeName.equals(ClassConstants.ATTR_LineNumberTable)                      ? (Attribute)new LineNumberTableAttribute():
            attributeName.equals(ClassConstants.ATTR_LocalVariableTable)                   ? (Attribute)new LocalVariableTableAttribute():
            attributeName.equals(ClassConstants.ATTR_LocalVariableTypeTable)               ? (Attribute)new LocalVariableTypeTableAttribute():
            attributeName.equals(ClassConstants.ATTR_RuntimeVisibleAnnotations)            ? (Attribute)new RuntimeVisibleAnnotationsAttribute():
            attributeName.equals(ClassConstants.ATTR_RuntimeInvisibleAnnotations)          ? (Attribute)new RuntimeInvisibleAnnotationsAttribute():
            attributeName.equals(ClassConstants.ATTR_RuntimeVisibleParameterAnnotations)   ? (Attribute)new RuntimeVisibleParameterAnnotationsAttribute():
            attributeName.equals(ClassConstants.ATTR_RuntimeInvisibleParameterAnnotations) ? (Attribute)new RuntimeInvisibleParameterAnnotationsAttribute():
            attributeName.equals(ClassConstants.ATTR_AnnotationDefault)                    ? (Attribute)new AnnotationDefaultAttribute():
                                                                                             (Attribute)new UnknownAttribute(u4attributeLength);
        attribute.u2attributeNameIndex = u2attributeNameIndex;

        return attribute;
    }


    private StackMapFrame createStackMapFrame()
    {
        int u1tag = dataInput.readUnsignedByte();

        return
            u1tag < StackMapFrame.SAME_ONE_FRAME           ? (StackMapFrame)new SameZeroFrame(u1tag) :
            u1tag < StackMapFrame.SAME_ONE_FRAME_EXTENDED  ? (StackMapFrame)new SameOneFrame(u1tag)  :
            u1tag < StackMapFrame.LESS_ZERO_FRAME          ? (StackMapFrame)new SameOneFrame(u1tag)  :
            u1tag < StackMapFrame.SAME_ZERO_FRAME_EXTENDED ? (StackMapFrame)new LessZeroFrame(u1tag) :
            u1tag < StackMapFrame.MORE_ZERO_FRAME          ? (StackMapFrame)new SameZeroFrame(u1tag) :
            u1tag < StackMapFrame.FULL_FRAME               ? (StackMapFrame)new MoreZeroFrame(u1tag) :
                                                             (StackMapFrame)new FullFrame();
    }


    private VerificationType createVerificationType()
    {
        int u1tag = dataInput.readUnsignedByte();

        switch (u1tag)
        {
            case VerificationType.INTEGER_TYPE:            return new IntegerType();
            case VerificationType.FLOAT_TYPE:              return new FloatType();
            case VerificationType.LONG_TYPE:               return new LongType();
            case VerificationType.DOUBLE_TYPE:             return new DoubleType();
            case VerificationType.TOP_TYPE:                return new TopType();
            case VerificationType.OBJECT_TYPE:             return new ObjectType();
            case VerificationType.NULL_TYPE:               return new NullType();
            case VerificationType.UNINITIALIZED_TYPE:      return new UninitializedType();
            case VerificationType.UNINITIALIZED_THIS_TYPE: return new UninitializedThisType();

            default: throw new RuntimeException("Unknown verification type ["+u1tag+"] in stack map frame");
        }
    }


    private ElementValue createElementValue()
    {
        int u1tag = dataInput.readUnsignedByte();

        switch (u1tag)
        {
            case ClassConstants.INTERNAL_TYPE_BOOLEAN:
            case ClassConstants.INTERNAL_TYPE_BYTE:
            case ClassConstants.INTERNAL_TYPE_CHAR:
            case ClassConstants.INTERNAL_TYPE_SHORT:
            case ClassConstants.INTERNAL_TYPE_INT:
            case ClassConstants.INTERNAL_TYPE_FLOAT:
            case ClassConstants.INTERNAL_TYPE_LONG:
            case ClassConstants.INTERNAL_TYPE_DOUBLE:
            case ClassConstants.ELEMENT_VALUE_STRING_CONSTANT: return new ConstantElementValue(u1tag);

            case ClassConstants.ELEMENT_VALUE_ENUM_CONSTANT:   return new EnumConstantElementValue();
            case ClassConstants.ELEMENT_VALUE_CLASS:           return new ClassElementValue();
            case ClassConstants.ELEMENT_VALUE_ANNOTATION:      return new AnnotationElementValue();
            case ClassConstants.ELEMENT_VALUE_ARRAY:           return new ArrayElementValue();

            default: throw new IllegalArgumentException("Unknown element value tag ["+u1tag+"]");
        }
    }
}