org.jikesrvm.classloader

Class UTF8Convert

java.lang.Object

org.jikesrvm.classloader.UTF8Convert

public abstract class UTF8Convert
extends Object

Abstract class that contains conversion routines to/from utf8 and/or pseudo-utf8. It does not support utf8 encodings of more than 3 bytes.

The difference between utf8 and pseudo-utf8 is the special treatment of null. In utf8, null is encoded as a single byte directly, whereas in pseudo-utf8, it is encoded as a two-byte sequence. See the JVM specification for more information.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	UTF8Convert.ByteArrayStringEncoderVisitor Visitor that builds up a char[] as characters are decoded
private static class	UTF8Convert.ByteBufferStringEncoderVisitor Visitor that builds up a char[] as characters are decoded
private static class	UTF8Convert.StringHashCodeVisitor Visitor that builds up a String.hashCode form hashCode as characters are decoded
private static class	UTF8Convert.UTF8CharacterVisitor UTF8 character visitor abstraction

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static boolean	ALLOW_NORMAL_UTF8 Set fromUTF8 to not throw an exception when given a normal utf8 byte array.
(package private) static boolean	ALLOW_PSEUDO_UTF8 Set fromUTF8 to not throw an exception when given a pseudo utf8 byte array.
(package private) static boolean	STRICTLY_CHECK_FORMAT Strictly check the format of the utf8/pseudo-utf8 byte array in fromUTF8.
(package private) static boolean	WRITE_PSEUDO_UTF8 Set toUTF8 to write in pseudo-utf8 (rather than normal utf8).

Constructor Summary

Constructors

Constructor and Description
UTF8Convert()

Method Summary

Modifier and Type	Method and Description
static boolean	check(byte[] bytes) Check whether the given sequence of bytes is valid (pseudo-)utf8.
static int	computeStringHashCode(byte[] utf8) Convert the given sequence of (pseudo-)utf8 formatted bytes into a String hashCode.
static String	fromUTF8(byte[] utf8) Convert the given sequence of (pseudo-)utf8 formatted bytes into a String.
static String	fromUTF8(ByteBuffer utf8) Convert the given sequence of (pseudo-)utf8 formatted bytes into a String.
private static void	throwDataFormatException(String message, int location)
static byte[]	toUTF8(String s) Convert the given String into a sequence of (pseudo-)utf8 formatted bytes.
static void	toUTF8(String s, ByteBuffer b) Convert the given String into a sequence of (pseudo-)utf8 formatted bytes.
static int	utfLength(String s)
private static void	visitUTF8(byte[] utf8, UTF8Convert.UTF8CharacterVisitor visitor) Visit all bytes of the given utf8 string calling the visitor when a character is decoded.
private static void	visitUTF8(ByteBuffer utf8, UTF8Convert.UTF8CharacterVisitor visitor) Visit all bytes of the given utf8 string calling the visitor when a character is decoded.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

STRICTLY_CHECK_FORMAT

static final boolean STRICTLY_CHECK_FORMAT

Strictly check the format of the utf8/pseudo-utf8 byte array in fromUTF8.

See Also:

Constant Field Values

ALLOW_NORMAL_UTF8

static final boolean ALLOW_NORMAL_UTF8

Set fromUTF8 to not throw an exception when given a normal utf8 byte array.

See Also:

Constant Field Values

ALLOW_PSEUDO_UTF8

static final boolean ALLOW_PSEUDO_UTF8

Set fromUTF8 to not throw an exception when given a pseudo utf8 byte array.

See Also:

Constant Field Values

WRITE_PSEUDO_UTF8

static final boolean WRITE_PSEUDO_UTF8

Set toUTF8 to write in pseudo-utf8 (rather than normal utf8).

See Also:

Constant Field Values

Constructor Detail

UTF8Convert

public UTF8Convert()

Method Detail

fromUTF8

public static String fromUTF8(byte[] utf8)
                       throws UTFDataFormatException

Convert the given sequence of (pseudo-)utf8 formatted bytes into a String.

The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8, and ALLOW_PSEUDO_UTF8 flags.

Parameters:

utf8 - (pseudo-)utf8 byte array

Returns:

unicode string

Throws:

UTFDataFormatException - if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8

fromUTF8

public static String fromUTF8(ByteBuffer utf8)
                       throws UTFDataFormatException

Convert the given sequence of (pseudo-)utf8 formatted bytes into a String. The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8, and ALLOW_PSEUDO_UTF8 flags.

Parameters:

utf8 - (pseudo-)utf8 byte array

Returns:

unicode string

Throws:

UTFDataFormatException - if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8

computeStringHashCode

public static int computeStringHashCode(byte[] utf8)
                                 throws UTFDataFormatException

Convert the given sequence of (pseudo-)utf8 formatted bytes into a String hashCode.

The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8, and ALLOW_PSEUDO_UTF8 flags.

Parameters:

utf8 - (pseudo-)utf8 byte array

Returns:

hashCode corresponding to if this were a String.hashCode

Throws:

UTFDataFormatException - if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8

throwDataFormatException

private static void throwDataFormatException(String message,
                                             int location)
                                      throws UTFDataFormatException

Throws:

UTFDataFormatException

visitUTF8

private static void visitUTF8(byte[] utf8,
                              UTF8Convert.UTF8CharacterVisitor visitor)
                       throws UTFDataFormatException

Visit all bytes of the given utf8 string calling the visitor when a character is decoded.

The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8, and ALLOW_PSEUDO_UTF8 flags.

Parameters:

utf8 - (pseudo-)utf8 byte array

visitor - called when characters are decoded

Throws:

UTFDataFormatException - if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8

visitUTF8

private static void visitUTF8(ByteBuffer utf8,
                              UTF8Convert.UTF8CharacterVisitor visitor)
                       throws UTFDataFormatException

Visit all bytes of the given utf8 string calling the visitor when a character is decoded.

The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8, and ALLOW_PSEUDO_UTF8 flags.

Parameters:

utf8 - (pseudo-)utf8 byte array

visitor - called when characters are decoded

Throws:

UTFDataFormatException - if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8

toUTF8

public static byte[] toUTF8(String s)

Convert the given String into a sequence of (pseudo-)utf8 formatted bytes.

The output format is controlled by the WRITE_PSEUDO_UTF8 flag.

Parameters:

s - String to convert

Returns:

array containing sequence of (pseudo-)utf8 formatted bytes

toUTF8

public static void toUTF8(String s,
                          ByteBuffer b)

Convert the given String into a sequence of (pseudo-)utf8 formatted bytes.

The output format is controlled by the WRITE_PSEUDO_UTF8 flag.

Parameters:

s - String to convert

b - Byte buffer to hold result

utfLength

public static int utfLength(String s)

check

public static boolean check(byte[] bytes)

Check whether the given sequence of bytes is valid (pseudo-)utf8.

Parameters:

bytes - byte array to check

Returns:

true iff the given sequence is valid (pseudo-)utf8.