Enum Class AccessFlag

java.lang.Object

java.lang.Enum<AccessFlag>

java.lang.reflect.AccessFlag

All Implemented Interfaces:: Serializable, Comparable<AccessFlag>, Constable

public enum AccessFlag extends Enum<AccessFlag>

Represents a JVM access or module-related flag on a runtime member, such as a class, field, or method.

JVM access and module-related flags are related to, but distinct from Java language modifiers. Some modifiers and access flags have a one-to-one correspondence, such as public. In other cases, some language-level modifiers do not have an access flag, such as sealed (JVMS Â§4.7.31) and some access flags have no corresponding modifier, such as synthetic.

The values for the constants representing the access and module flags are taken from sections of The Java Virtual Machine Specification including Â§4.1 (class access and property modifiers), Â§4.5 (field access and property flags), Â§4.6 (method access and property flags), Â§4.7.6 (nested class access and property flags), Â§4.7.24 (method parameters), and Â§4.7.25 (module flags and requires, exports, and opens flags).

The mask values for the different access flags are not distinct. Flags are defined for different kinds of JVM structures and the same bit position has different meanings in different contexts. For example, 0x0000_0040 indicates a volatile field but a bridge method; 0x0000_0080 indicates a transient field but a variable arity (varargs) method.

API Note:

The JVM class file format has a new version defined for each new feature release. A new class file version may define new access flags or retire old ones.


AccessFlag

is intended to model the set of access flags across class file format versions. The range of versions an access flag is recognized is not explicitly indicated in this API. See the current The Java Virtual Machine Specification for details. Unless otherwise indicated, access flags can be assumed to be recognized in the current version.

Implementation Requirements:

The access flag constants are ordered by non-decreasing mask value; that is the mask value of a constant is greater than or equal to the mask value of an immediate neighbor to its (syntactic) left. If new constants are added, this property will be maintained. That implies new constants will not necessarily be added at the end of the existing list.

Since:

See Also:

Nested Class Summary

Modifier and Type	Class	Description
`static enum`	`AccessFlag.Location`	A location within a `class` file where flags can be applied.

Nested classes/interfaces declared in class Enum

Enum.EnumDesc<E>

Modifier and Type	Class	Description
`static final class`	`Enum.EnumDesc<E extends Enum<E>>`	A nominal descriptor for an `enum` constant.

Enum Constant Summary

Enum Constant	Description
`ABSTRACT`	The access flag `ACC_ABSTRACT`, corresponding to the source modifier `abstract`, with a mask value of `0x0400`.
`ANNOTATION`	The access flag `ACC_ANNOTATION` with a mask value of `0x2000`.
`BRIDGE`	The access flag `ACC_BRIDGE` with a mask value of `0x0040`
`ENUM`	The access flag `ACC_ENUM` with a mask value of `0x4000`.
`FINAL`	The access flag `ACC_FINAL`, corresponding to the source modifier `final`, with a mask value of `0x0010`.
`INTERFACE`	The access flag `ACC_INTERFACE` with a mask value of `0x0200`.
`MANDATED`	The access flag `ACC_MANDATED` with a mask value of `0x8000`.
`MODULE`	The access flag `ACC_MODULE` with a mask value of `0x8000`.
`NATIVE`	The access flag `ACC_NATIVE`, corresponding to the source modifier `native`, with a mask value of `0x0100`.
`OPEN`	The module flag `ACC_OPEN` with a mask value of `0x0020`.
`PRIVATE`	The access flag `ACC_PRIVATE`, corresponding to the source modifier `private`, with a mask value of `0x0002`.
`PROTECTED`	The access flag `ACC_PROTECTED`, corresponding to the source modifier `protected`, with a mask value of `0x0004`.
`PUBLIC`	The access flag `ACC_PUBLIC`, corresponding to the source modifier `public`, with a mask value of `0x0001`.
`STATIC`	The access flag `ACC_STATIC`, corresponding to the source modifier `static`, with a mask value of `0x0008`.
`STATIC_PHASE`	The module requires flag `ACC_STATIC_PHASE` with a mask value of `0x0040`.
`STRICT`	The access flag `ACC_STRICT`, corresponding to the source modifier `strictfp`, with a mask value of `0x0800`.
`SUPER`	The access flag `ACC_SUPER` with a mask value of `0x0020`.
`SYNCHRONIZED`	The access flag `ACC_SYNCHRONIZED`, corresponding to the source modifier `synchronized`, with a mask value of `0x0020`.
`SYNTHETIC`	The access flag `ACC_SYNTHETIC` with a mask value of `0x1000`.
`TRANSIENT`	The access flag `ACC_TRANSIENT`, corresponding to the source modifier `transient`, with a mask value of `0x0080`.
`TRANSITIVE`	The module requires flag `ACC_TRANSITIVE` with a mask value of `0x0020`.
`VARARGS`	The access flag `ACC_VARARGS` with a mask value of `0x0080`.
`VOLATILE`	The access flag `ACC_VOLATILE`, corresponding to the source modifier `volatile`, with a mask value of `0x0040`.

Method Summary

Modifier and Type	Method	Description
`Set<AccessFlag.Location>`	`locations()`	Returns locations this flag can be applied to in the current class file format version.
`Set<AccessFlag.Location>`	`locations(ClassFileFormatVersion cffv)`	Returns locations this flag can be applied to in the given class file format version.
`int`	`mask()`	Returns the corresponding mask for the access flag.
`static Set<AccessFlag>`	`maskToAccessFlags(int mask, AccessFlag.Location location)`	Returns an unmodifiable set of access flags for the given mask value appropriate for the location in the current class file format version.
`static Set<AccessFlag>`	`maskToAccessFlags(int mask, AccessFlag.Location location, ClassFileFormatVersion cffv)`	Returns an unmodifiable set of access flags for the given mask value appropriate for the location in the given class file format version.
`boolean`	`sourceModifier()`	Returns whether or not this flag has a directly corresponding modifier in the Java programming language.
`static AccessFlag`	`valueOf(String name)`	Returns the enum constant of this class with the specified name.
`static AccessFlag[]`	`values()`	Returns an array containing the constants of this enum class, in the order they are declared.

Methods declared in class Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Modifier and Type	Method	Description
`protected final Object`	`clone()`	Throws CloneNotSupportedException.
`final int`	`compareTo(AccessFlag o)`	Compares this enum with the specified object for order.
`final Optional<Enum.EnumDesc<AccessFlag>>`	`describeConstable()`	Returns an enum descriptor `EnumDesc` for this instance, if one can be constructed, or an empty `Optional` if one cannot be.
`final boolean`	`equals(Object other)`	Returns true if the specified object is equal to this enum constant.
`protected final void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization has been deprecated for removal.
`final Class<AccessFlag>`	`getDeclaringClass()`	Returns the Class object corresponding to this enum constant's enum type.
`final int`	`hashCode()`	Returns a hash code for this enum constant.
`final String`	`name()`	Returns the name of this enum constant, exactly as declared in its enum declaration.
`final int`	`ordinal()`	Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero).
`String`	`toString()`	Returns the name of this enum constant, as contained in the declaration.
`static <T extends Enum<T>> T`	`valueOf(Class<T> enumClass, String name)`	Returns the enum constant of the specified enum class with the specified name.

Methods declared in class Object

getClass, notify, notifyAll, wait, wait, wait

Modifier and Type	Method	Description
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Enum Constant Details

PUBLIC

public static final AccessFlag PUBLIC

The access flag ACC_PUBLIC, corresponding to the source modifier public, with a mask value of 0x0001.

PRIVATE

public static final AccessFlag PRIVATE

The access flag ACC_PRIVATE, corresponding to the source modifier private, with a mask value of 0x0002.

PROTECTED

public static final AccessFlag PROTECTED

The access flag ACC_PROTECTED, corresponding to the source modifier protected, with a mask value of 0x0004.

STATIC

public static final AccessFlag STATIC

The access flag ACC_STATIC, corresponding to the source modifier static, with a mask value of 0x0008.

FINAL

public static final AccessFlag FINAL

The access flag ACC_FINAL, corresponding to the source modifier final, with a mask value of 0x0010.

SUPER

public static final AccessFlag SUPER

The access flag ACC_SUPER with a mask value of


0x0020

API Note:: In Java SE 8 and above, the JVM treats the ACC_SUPER flag as set in every class file (JVMS Â§4.1).

OPEN

public static final AccessFlag OPEN

The module flag ACC_OPEN with a mask value of


0x0020

See Also:

TRANSITIVE

public static final AccessFlag TRANSITIVE

The module requires flag ACC_TRANSITIVE with a mask value of 0x0020.

See Also:

SYNCHRONIZED

public static final AccessFlag SYNCHRONIZED

The access flag ACC_SYNCHRONIZED, corresponding to the source modifier synchronized, with a mask value of 0x0020.

STATIC_PHASE

public static final AccessFlag STATIC_PHASE

The module requires flag ACC_STATIC_PHASE with a mask value of 0x0040.

See Also:

VOLATILE

public static final AccessFlag VOLATILE

The access flag ACC_VOLATILE, corresponding to the source modifier volatile, with a mask value of 0x0040.

BRIDGE

public static final AccessFlag BRIDGE

The access flag ACC_BRIDGE with a mask value of 0x0040

See Also:

TRANSIENT

public static final AccessFlag TRANSIENT

The access flag ACC_TRANSIENT, corresponding to the source modifier transient, with a mask value of 0x0080.

VARARGS

public static final AccessFlag VARARGS

The access flag ACC_VARARGS with a mask value of 0x0080.

See Also:

NATIVE

public static final AccessFlag NATIVE

The access flag ACC_NATIVE, corresponding to the source modifier native, with a mask value of 0x0100.

INTERFACE

public static final AccessFlag INTERFACE

The access flag ACC_INTERFACE with a mask value of 0x0200.

See Also:

ABSTRACT

public static final AccessFlag ABSTRACT

The access flag ACC_ABSTRACT, corresponding to the source modifier abstract, with a mask value of 0x0400.

STRICT

public static final AccessFlag STRICT

The access flag ACC_STRICT, corresponding to the source modifier strictfp, with a mask value of 0x0800.

API Note:: The ACC_STRICT access flag is defined for class file major versions 46 through 60, inclusive (JVMS Â§4.6), corresponding to Java SE 1.2 through 16.

SYNTHETIC

public static final AccessFlag SYNTHETIC

The access flag ACC_SYNTHETIC with a mask value of 0x1000.

See Also:

ANNOTATION

public static final AccessFlag ANNOTATION

The access flag ACC_ANNOTATION with a mask value of 0x2000.

See Also:

ENUM

public static final AccessFlag ENUM

The access flag ACC_ENUM with a mask value of 0x4000.

See Also:

MANDATED

public static final AccessFlag MANDATED

The access flag ACC_MANDATED with a mask value of 0x8000.

MODULE

public static final AccessFlag MODULE

The access flag ACC_MODULE with a mask value of


0x8000

Method Details

values

public static AccessFlag[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:: an array containing the constants of this enum class, in the order they are declared

valueOf

public static AccessFlag valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:: name - the name of the enum constant to be returned.
Returns:: the enum constant with the specified name
Throws:: IllegalArgumentException - if this enum class has no constant with the specified name; NullPointerException - if the argument is null

mask

public int mask()

Returns the corresponding mask for the access flag. The mask has exactly one bit set and is in the range of char.

Returns:: the corresponding mask for the access flag

sourceModifier

public boolean sourceModifier()

Returns whether or not this flag has a directly corresponding modifier in the Java programming language.

Returns:: whether or not this flag has a directly corresponding modifier in the Java programming language

locations

public Set<AccessFlag.Location> locations()

Returns locations this flag can be applied to in the current class file format version.

This method returns an empty set if this flag is not defined in the current class file format version.

Returns:: locations this flag can be applied to in the current class file format version

locations

public Set<AccessFlag.Location> locations(ClassFileFormatVersion cffv)

Returns locations this flag can be applied to in the given class file format version.

This method returns an empty set if this flag is not defined in the given cffv.

Parameters:: cffv - the class file format version to use
Returns:: locations this flag can be applied to in the given class file format version
Throws:: NullPointerException - if the parameter is null

maskToAccessFlags

public static Set<AccessFlag> maskToAccessFlags(int mask, AccessFlag.Location location)

Returns an unmodifiable set of access flags for the given mask value appropriate for the location in the current class file format version.

Parameters:: mask - bit mask of access flags; location - context to interpret mask value
Returns:: an unmodifiable set of access flags for the given mask value appropriate for the location in the current class file format version
Throws:: IllegalArgumentException - if the mask contains bit positions not defined for the location in the current class file format; NullPointerException - if location is null

maskToAccessFlags

public static Set<AccessFlag> maskToAccessFlags(int mask, AccessFlag.Location location, ClassFileFormatVersion cffv)

Returns an unmodifiable set of access flags for the given mask value appropriate for the location in the given class file format version.

Parameters:: mask - bit mask of access flags; location - context to interpret mask value; cffv - the class file format to interpret mask value
Returns:: an unmodifiable set of access flags for the given mask value appropriate for the location in the given class file format version
Throws:: IllegalArgumentException - if the mask contains bit positions not defined for the location in the given class file format; NullPointerException - if location or cffv is null
Since:: 25

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.