Package org.apache.bcel.classfile

Class Attribute

java.lang.Object
org.apache.bcel.classfile.Attribute
All Implemented Interfaces:
Cloneable, Node
Direct Known Subclasses:
AnnotationDefault, Annotations, BootstrapMethods, Code, ConstantValue, Deprecated, EnclosingMethod, ExceptionTable, InnerClasses, LineNumberTable, LocalVariableTable, LocalVariableTypeTable, MethodParameters, Module, ModuleMainClass, ModulePackages, NestHost, NestMembers, ParameterAnnotations, PMGClass, Record, Signature, SourceFile, StackMap, Synthetic, Unknown
public abstract class Attribute extends Object implements Cloneable, Node
Abstract super class for Attribute objects. Currently the ConstantValue, SourceFile, Code, Exceptiontable, LineNumberTable, LocalVariableTable, InnerClasses and Synthetic attributes are supported. The Unknown attribute stands for non-standard-attributes. 
 attribute_info {
   u2 attribute_name_index;
   u4 attribute_length;
   u1 info[attribute_length];
 }
See Also:

  • Field Details

    • EMPTY_ARRAY

      public static final Attribute[] EMPTY_ARRAY
      Empty array.
      Since:
      6.6.0

    • name_index

      @Deprecated protected int name_index
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

    • length

      @Deprecated protected int length
      Deprecated.
      (since 6.0) (since 6.0) will be made private; do not access directly, use getter/setter

    • tag

      @Deprecated protected byte tag
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

    • constant_pool

      @Deprecated protected ConstantPool constant_pool
      Deprecated.
      (since 6.0) will be made private; do not access directly, use getter/setter

  • Constructor Details

    • Attribute

      protected Attribute(byte tag, int nameIndex, int length, ConstantPool constantPool)
      Constructs an instance. 
       attribute_info {
   u2 attribute_name_index;
   u4 attribute_length;
   u1 info[attribute_length];
 }
      Parameters:
      tag - tag.
      nameIndex - u2 name index.
      length - u4 length.
      constantPool - constant pool.

  • Method Details

    • addAttributeReader

      @Deprecated public static void addAttributeReader(String name, AttributeReader attributeReader)
      Deprecated.
      (6.0) Use addAttributeReader(String, UnknownAttributeReader) instead
      Add an Attribute reader capable of parsing (user-defined) attributes named "name". You should not add readers for the standard attributes such as "LineNumberTable", because those are handled internally.
      Parameters:
      name - the name of the attribute as stored in the class file
      attributeReader - the reader object

    • addAttributeReader

      public static void addAttributeReader(String name, UnknownAttributeReader unknownAttributeReader)
      Add an Attribute reader capable of parsing (user-defined) attributes named "name". You should not add readers for the standard attributes such as "LineNumberTable", because those are handled internally.
      Parameters:
      name - the name of the attribute as stored in the class file
      unknownAttributeReader - the reader object

    • println

      protected static void println(String msg)

    • readAttribute

      public static Attribute readAttribute(DataInput dataInput, ConstantPool constantPool) throws IOException
      Class method reads one attribute from the input data stream. This method must not be accessible from the outside. It is called by the Field and Method constructor methods.
      Parameters:
      dataInput - Input stream
      constantPool - Array of constants
      Returns:
      Attribute
      Throws:
      IOException - if an I/O error occurs.
      Since:
      6.0
      See Also:

    • readAttribute

      public static Attribute readAttribute(DataInputStream dataInputStream, ConstantPool constantPool) throws IOException
      Class method reads one attribute from the input data stream. This method must not be accessible from the outside. It is called by the Field and Method constructor methods.
      Parameters:
      dataInputStream - Input stream
      constantPool - Array of constants
      Returns:
      Attribute
      Throws:
      IOException - if an I/O error occurs.
      See Also:

    • removeAttributeReader

      public static void removeAttributeReader(String name)
      Remove attribute reader
      Parameters:
      name - the name of the attribute as stored in the class file

    • accept

      public abstract void accept(Visitor v)
      Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
      Specified by:
      accept in interface Node
      Parameters:
      v - Visitor object

    • clone

      public Object clone()
      Use copy() if you want to have a deep copy(), i.e., with all references copied correctly.
      Overrides:
      clone in class Object
      Returns:
      shallow copy of this attribute

    • copy

      public abstract Attribute copy(ConstantPool constantPool)
      Parameters:
      constantPool - constant pool to save.
      Returns:
      deep copy of this attribute.

    • dump

      public void dump(DataOutputStream file) throws IOException
      Dumps attribute to file stream in binary format.
      Parameters:
      file - Output file stream
      Throws:
      IOException - if an I/O error occurs.

    • getConstantPool

      public final ConstantPool getConstantPool()
      Returns:
      Constant pool used by this object.
      See Also:

    • getLength

      public final int getLength()
      Returns:
      Length of attribute field in bytes.

    • getName

      public String getName()
      Returns:
      Name of attribute
      Since:
      6.0

    • getNameIndex

      public final int getNameIndex()
      Returns:
      Name index in constant pool of attribute name.

    • getTag

      public final byte getTag()
      Returns:
      Tag of attribute, i.e., its type. Value may not be altered, thus there is no setTag() method.

    • setConstantPool

      public final void setConstantPool(ConstantPool constantPool)
      Parameters:
      constantPool - Constant pool to be used for this object.
      See Also:

    • setLength

      public final void setLength(int length)
      Parameters:
      length - length in bytes.

    • setNameIndex

      public final void setNameIndex(int nameIndex)
      Parameters:
      nameIndex - of attribute.

    • toString

      public String toString()
      Overrides:
      toString in class Object
      Returns:
      attribute name.