Interface Utf8Entry

All Superinterfaces:: AnnotationConstantValueEntry, CharSequence, PoolEntry

public sealed interface Utf8Entry extends CharSequence, AnnotationConstantValueEntry

Models a CONSTANT_UTF8_info constant, representing strings, in the constant pool of a class file. This describes strings in the Modified UTF-8 format.

The use of a Utf8Entry is represented by a String. Conversions are through ConstantPoolBuilder.utf8Entry(String) and stringValue().

Some uses of Utf8Entry represent field or method descriptor strings, symbolically represented as ClassDesc or MethodTypeDesc, depending on where a Utf8Entry appear. Entries representing such uses are created with ConstantPoolBuilder.utf8Entry(ClassDesc) and ConstantPoolBuilder.utf8Entry(MethodTypeDesc), and they can be converted to symbolic descriptors on a per-use-site basis, such as in AnnotationValue.OfClass.classSymbol() and MethodModel.methodTypeSymbol().

Unlike most constant pool entries, a UTF-8 entry is of flexible length: it is represented as an array structure, with an u2 for the data length in bytes, followed by that number of bytes of Modified UTF-8 data. It can represent at most 65535 bytes of data due to the physical restrictions of u2.

See Java Virtual Machine Specification:

4.4.7 The CONSTANT_Utf8_info Structure

Since:

See Also:

Field Summary

Fields declared in interface PoolEntry

TAG_CLASS, TAG_DOUBLE, TAG_DYNAMIC, TAG_FIELDREF, TAG_FLOAT, TAG_INTEGER, TAG_INTERFACE_METHODREF, TAG_INVOKE_DYNAMIC, TAG_LONG, TAG_METHOD_HANDLE, TAG_METHOD_TYPE, TAG_METHODREF, TAG_MODULE, TAG_NAME_AND_TYPE, TAG_PACKAGE, TAG_STRING, TAG_UTF8

Modifier and Type	Field	Description
`static final int`	`TAG_CLASS`	The tag for `CONSTANT_Class` constant kind.
`static final int`	`TAG_DOUBLE`	The tag for `CONSTANT_Double` constant kind.
`static final int`	`TAG_DYNAMIC`	The tag for `CONSTANT_Dynamic` constant kind.
`static final int`	`TAG_FIELDREF`	The tag for `CONSTANT_Fieldref` constant kind.
`static final int`	`TAG_FLOAT`	The tag for `CONSTANT_Float` constant kind.
`static final int`	`TAG_INTEGER`	The tag for `CONSTANT_Integer` constant kind.
`static final int`	`TAG_INTERFACE_METHODREF`	The tag for `CONSTANT_InterfaceMethodref` constant kind.
`static final int`	`TAG_INVOKE_DYNAMIC`	The tag for `CONSTANT_InvokeDynamic` constant kind.
`static final int`	`TAG_LONG`	The tag for `CONSTANT_Long` constant kind.
`static final int`	`TAG_METHOD_HANDLE`	The tag for `CONSTANT_MethodHandle` constant kind.
`static final int`	`TAG_METHOD_TYPE`	The tag for `CONSTANT_MethodType` constant kind.
`static final int`	`TAG_METHODREF`	The tag for `CONSTANT_Methodref` constant kind.
`static final int`	`TAG_MODULE`	The tag for `CONSTANT_Module` constant kind.
`static final int`	`TAG_NAME_AND_TYPE`	The tag for `CONSTANT_NameAndType` constant kind.
`static final int`	`TAG_PACKAGE`	The tag for `CONSTANT_Package` constant kind.
`static final int`	`TAG_STRING`	The tag for `CONSTANT_String` constant kind.
`static final int`	`TAG_UTF8`	The tag for `CONSTANT_Utf8` constant kind.

Method Summary

Modifier and Type	Method	Description
`boolean`	`equalsString(String s)`	Returns whether this entry describes the same string as the provided string.
`boolean`	`isFieldType(ClassDesc desc)`	Returns whether this entry describes the descriptor string of this field type.
`boolean`	`isMethodType(MethodTypeDesc desc)`	Returns whether this entry describes the descriptor string of this method type.
`String`	`stringValue()`	Returns the string value for this entry.

Methods declared in interface AnnotationConstantValueEntry

constantValue

Modifier and Type	Method	Description
`ConstantDesc`	`constantValue()`	Returns the constant value.

Methods declared in interface CharSequence

charAt, chars, codePoints, getChars, isEmpty, length, subSequence, toString

Modifier and Type	Method	Description
`char`	`charAt(int index)`	Returns the `char` value at the specified index.
`default IntStream`	`chars()`	Returns a stream of `int` zero-extending the `char` values from this sequence.
`default IntStream`	`codePoints()`	Returns a stream of code point values from this sequence.
`default void`	`getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)`	Copies characters from this sequence into the given destination array.
`default boolean`	`isEmpty()`	Returns `true` if this character sequence is empty.
`int`	`length()`	Returns the length of this character sequence.
`CharSequence`	`subSequence(int start, int end)`	Returns a `CharSequence` that is a subsequence of this sequence.
`String`	`toString()`	Returns a string containing the characters in this sequence in the same order as this sequence.

Methods declared in interface PoolEntry

constantPool, index, tag, width

Modifier and Type	Method	Description
`ConstantPool`	`constantPool()`	Returns the constant pool this entry is from.
`int`	`index()`	Returns the index within the constant pool corresponding to this entry.
`int`	`tag()`	Returns the constant pool tag that describes the type of this entry.
`int`	`width()`	Returns the number of constant pool slots this entry consumes.

Method Details

stringValue

String stringValue()

Returns the string value for this entry.

API Note:

A Utf8Entry can be used directly as a CharSequence if String functionalities are not strictly desired. If only string equivalence is desired, equalsString should be used. Reduction of string processing can significantly improve


class

file reading performance.

Returns:

the string value for this entry

See Also:

equalsString

boolean equalsString(String s)

Returns whether this entry describes the same string as the provided string.

Parameters:: s - the string to compare to
Returns:: whether this entry describes the same string as the provided string

isFieldType

boolean isFieldType(ClassDesc desc)

Returns whether this entry describes the descriptor string of this field type.

Parameters:: desc - the field type
Returns:: whether this entry describes the descriptor string of this field type
Since:: 25

isMethodType

boolean isMethodType(MethodTypeDesc desc)

Returns whether this entry describes the descriptor string of this method type.

Parameters:: desc - the method type
Returns:: whether this entry describes the descriptor string of this method type
Since:: 25

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