Package org.apache.bcel.classfile

Class Constant

java.lang.Object
org.apache.bcel.classfile.Constant
All Implemented Interfaces:
Cloneable, Node
Direct Known Subclasses:
ConstantClass, ConstantCP, ConstantDouble, ConstantFloat, ConstantInteger, ConstantLong, ConstantMethodHandle, ConstantMethodType, ConstantModule, ConstantNameAndType, ConstantPackage, ConstantString, ConstantUtf8
public abstract class Constant extends Object implements Cloneable, Node
Abstract superclass for classes to represent the different constant types in the constant pool of a class file. The classes keep closely to the JVM specification.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected byte
    tag
    Deprecated.
    (since 6.0) will be made private; do not access directly, use getter/setter.

  • Method Summary

    Modifier and Type
    Method
    Description
    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.
    Object
    clone()
     
    Constant
    copy()
    Creates a deep copy of this constant.
    abstract void
    dump(DataOutputStream file)
    Dumps constant to file stream in binary format.
    boolean
    equals(Object obj)
    Returns value as defined by given BCELComparator strategy.
    static BCELComparator<Constant>
    getComparator()
    Gets the comparison strategy object.
    final byte
    getTag()
    Gets the tag of constant.
    int
    hashCode()
    Returns value as defined by given BCELComparator strategy.
    static Constant
    readConstant(DataInput dataInput)
    Reads one constant from the given input, the type depends on a tag byte.
    static void
    setComparator(BCELComparator<Constant> comparator)
    Sets the comparison strategy object.
    String
    toString()
     

    Methods inherited from class java.lang.Object

    finalize, getClass, notify, notifyAll, wait, wait, wait

  • Field Details

    • tag

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

  • Method Details

    • getComparator

      public static BCELComparator<Constant> getComparator()
      Gets the comparison strategy object.
      Returns:
      Comparison strategy object.

    • readConstant

      public static Constant readConstant(DataInput dataInput) throws IOException, ClassFormatException
      Reads one constant from the given input, the type depends on a tag byte.
      Parameters:
      dataInput - Input stream.
      Returns:
      Constant object.
      Throws:
      IOException - Thrown if an I/O error occurs reading from the given dataInput.
      ClassFormatException - Thrown if the next byte is not recognized
      Since:
      6.0 made public

    • setComparator

      public static void setComparator(BCELComparator<Constant> comparator)
      Sets the comparison strategy object.
      Parameters:
      comparator - Comparison strategy object.

    • 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()
      Overrides:
      clone in class Object

    • copy

      public Constant copy()
      Creates a deep copy of this constant.
      Returns:
      deep copy of this constant.

    • dump

      public abstract void dump(DataOutputStream file) throws IOException
      Dumps constant to file stream in binary format.
      Parameters:
      file - The output stream.
      Throws:
      IOException - Thrown if an I/O error occurs.

    • equals

      public boolean equals(Object obj)
      Returns value as defined by given BCELComparator strategy. By default two Constant objects are said to be equal when the result of toString() is equal.
      Overrides:
      equals in class Object
      See Also:

    • getTag

      public final byte getTag()
      Gets the tag of constant.
      Returns:
      Tag of constant, that is, its type. No setTag() method to avoid confusion.

    • hashCode

      public int hashCode()
      Returns value as defined by given BCELComparator strategy. By default return the hash code of the result of toString().
      Overrides:
      hashCode in class Object
      See Also:

    • toString

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