java.lang.Object
- com.ibm.wala.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:

Serialized Form

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Atom`	`arrayDescriptorFromElementDescriptor()`	Return array descriptor corresponding to "this" array-element descriptor.
`static Atom`	`concat(byte c, ImmutableByteArray b)`
`static Atom`	`concat(Atom ma, Atom mb)`
`boolean`	`contains(byte b)`
`boolean`	`equals(Object obj)`
`static Atom`	`findOrCreate(byte[] bytes)`
`static Atom`	`findOrCreate(byte[] utf8, int off, int len)`	create an Atom from utf8[off] of length len
`static Atom`	`findOrCreate(ImmutableByteArray b)`
`static Atom`	`findOrCreate(ImmutableByteArray b, int start, int length)`
`static Atom`	`findOrCreateAsciiAtom(String str)`	Find or create an atom.
`static Atom`	`findOrCreateUnicodeAtom(String str)`	Find or create an atom.
`static Atom`	`findOrCreateUtf8Atom(byte[] utf8)`	Find or create an atom.
`byte`	`getVal(int i)`
`byte[]`	`getValArray()`	return an array of bytes representing the utf8 characters in this
`int`	`hashCode()`
`boolean`	`isArrayDescriptor()`	Is "this" atom an array descriptor?
`static boolean`	`isArrayDescriptor(ImmutableByteArray b)`
`boolean`	`isClassDescriptor()`	Is "this" atom a class descriptor?
`boolean`	`isMethodDescriptor()`	Is "this" atom a method descriptor?
`boolean`	`isReservedMemberName()`	Is "this" atom a reserved member name? Note: Sun has reserved all member names starting with '<' for future use.
`Atom`	`left(int count)`	New Atom containing first count bytes
`int`	`length()`
`int`	`parseForArrayDimensionality()`	Parse "this" array descriptor to obtain number of dimensions in corresponding array type.
`Atom`	`parseForArrayElementDescriptor()`	Parse "this" array descriptor to obtain descriptor for array's element type.
`Atom`	`parseForInnermostArrayElementDescriptor()`	Return the innermost element type reference for an array
`Atom`	`right(int count)`	New Atom containing last count bytes
`int`	`rIndex(byte b)`
`boolean`	`startsWith(Atom start)`
`String`	`toString()`	Return printable representation of "this" atom.
`String`	`toUnicodeString()`	Return printable representation of "this" atom.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Method Detail
  - 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 final String toString()
```
    Return printable representation of "this" atom. Does not correctly handle UTF8 translation.
    
    Overrides:
    
    toString in class Object
  - toUnicodeString
```
public final String toUnicodeString()
                             throws UTFDataFormatException
```
    Return printable representation of "this" atom.
    
    Throws:
    
    UTFDataFormatException
  - left
```
public final Atom left(int count)
```
    New Atom containing first count bytes
  - right
```
public final Atom right(int count)
```
    New Atom containing last count bytes
  - startsWith
```
public final boolean startsWith(Atom start)
```
  - arrayDescriptorFromElementDescriptor
```
public final 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 final boolean isReservedMemberName()
```
    Is "this" atom a reserved member name? Note: Sun has reserved all member names starting with '<' for future use. At present, only and are used.
  - isClassDescriptor
```
public final boolean isClassDescriptor()
```
    Is "this" atom a class descriptor?
  - isArrayDescriptor
```
public final boolean isArrayDescriptor()
```
    Is "this" atom an array descriptor?
  - isMethodDescriptor
```
public final boolean isMethodDescriptor()
                                 throws IllegalArgumentException
```
    Is "this" atom a method descriptor?
    
    Throws:
    
    IllegalArgumentException
  - length
```
public final int length()
```
  - parseForArrayElementDescriptor
```
public final 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 final 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 final 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
    
    See Also:
    
    Object.hashCode()
  - 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)
```

Class Atom

Method Summary

Methods inherited from class java.lang.Object

Method Detail

findOrCreateUnicodeAtom

findOrCreateAsciiAtom

findOrCreateUtf8Atom

findOrCreate

findOrCreate

findOrCreate

findOrCreate

toString

toUnicodeString

left

right

startsWith

arrayDescriptorFromElementDescriptor

isReservedMemberName

isClassDescriptor

isArrayDescriptor

isMethodDescriptor

length

parseForArrayElementDescriptor

parseForArrayDimensionality

parseForInnermostArrayElementDescriptor

hashCode

equals

getValArray

getVal

contains

rIndex

concat

concat

isArrayDescriptor