Class Atom

java.lang.Object
com.ibm.wala.core.util.strings.Atom
All Implemented Interfaces:
Serializable
public final class Atom extends Object implements Serializable
An utf8-encoded byte string.

Atom's are interned (canonicalized) so they may be compared for equality using the "==" operator.

Atoms are used to represent names, descriptors, and string literals appearing in a class's constant pool.

See Also:

  • Method Details

    • findOrCreateUnicodeAtom

      public static Atom findOrCreateUnicodeAtom(String str)
      Find or create an atom.
      Parameters:
      str - atom value, as string literal whose characters are unicode
      Returns:
      atom

    • findOrCreateAsciiAtom

      public static Atom findOrCreateAsciiAtom(String str)
      Find or create an atom.
      Parameters:
      str - atom value, as string literal whose characters are from ascii subset of unicode (not including null)
      Returns:
      atom
      Throws:
      IllegalArgumentException - if str is null

    • findOrCreateUtf8Atom

      public static Atom findOrCreateUtf8Atom(byte[] utf8)
      Find or create an atom.
      Parameters:
      utf8 - atom value, as utf8 encoded bytes
      Returns:
      atom
      Throws:
      IllegalArgumentException - if utf8 is null

    • findOrCreate

      public static Atom findOrCreate(byte[] utf8, int off, int len) throws IllegalArgumentException, IllegalArgumentException, IllegalArgumentException
      create an Atom from utf8[off] of length len
      Throws:
      IllegalArgumentException - if utf8.length <= off

    • findOrCreate

      public static Atom findOrCreate(byte[] bytes)

    • findOrCreate

      public static Atom findOrCreate(ImmutableByteArray b)

    • findOrCreate

      public static Atom findOrCreate(ImmutableByteArray b, int start, int length)

    • toString

      public String toString()
      Return printable representation of "this" atom. Does not correctly handle UTF8 translation.
      Overrides:
      toString in class Object

    • toUnicodeString

      public String toUnicodeString() throws UTFDataFormatException
      Return printable representation of "this" atom.
      Throws:
      UTFDataFormatException

    • left

      public Atom left(int count)
      New Atom containing first count bytes

    • right

      public Atom right(int count)
      New Atom containing last count bytes

    • startsWith

      public boolean startsWith(Atom start)

    • arrayDescriptorFromElementDescriptor

      public Atom arrayDescriptorFromElementDescriptor()
      Return array descriptor corresponding to "this" array-element descriptor. this: array-element descriptor - something like "I" or "Ljava/lang/Object;"
      Returns:
      array descriptor - something like "[I" or "[Ljava/lang/Object;"

    • isReservedMemberName

      public boolean isReservedMemberName()
      Is "this" atom a reserved member name? Note: Sun has reserved all member names starting with '<' for future use. At present, only <init> and <clinit> are used.

    • isClassDescriptor

      public boolean isClassDescriptor()
      Is "this" atom a class descriptor?

    • isArrayDescriptor

      public boolean isArrayDescriptor()
      Is "this" atom an array descriptor?

    • isMethodDescriptor

      public boolean isMethodDescriptor() throws IllegalArgumentException
      Is "this" atom a method descriptor?
      Throws:
      IllegalArgumentException

    • length

      public int length()

    • parseForArrayElementDescriptor

      public Atom parseForArrayElementDescriptor() throws IllegalArgumentException
      Parse "this" array descriptor to obtain descriptor for array's element type. this: array descriptor - something like "[I"
      Returns:
      array element descriptor - something like "I"
      Throws:
      IllegalArgumentException

    • parseForArrayDimensionality

      public int parseForArrayDimensionality() throws IllegalArgumentException
      Parse "this" array descriptor to obtain number of dimensions in corresponding array type. this: descriptor - something like "[Ljava/lang/String;" or "[[I"
      Returns:
      dimensionality - something like "1" or "2"
      Throws:
      IllegalStateException - if this Atom does not represent an array
      IllegalArgumentException

    • parseForInnermostArrayElementDescriptor

      public Atom parseForInnermostArrayElementDescriptor() throws IllegalArgumentException
      Return the innermost element type reference for an array
      Throws:
      IllegalStateException - if this Atom does not represent an array descriptor
      IllegalArgumentException

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • getValArray

      public byte[] getValArray()
      return an array of bytes representing the utf8 characters in this

    • getVal

      public byte getVal(int i) throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • contains

      public boolean contains(byte b)
      Returns:
      true iff this atom contains the specified byte

    • rIndex

      public int rIndex(byte b)

    • concat

      public static Atom concat(byte c, ImmutableByteArray b)

    • concat

      public static Atom concat(Atom ma, Atom mb)

    • isArrayDescriptor

      public static boolean isArrayDescriptor(ImmutableByteArray b)