Class ObjectMethods

java.lang.Object

java.lang.runtime.ObjectMethods

public final class ObjectMethods
extends Object

Bootstrap methods for state-driven implementations of core methods, including Object.equals(Object), Object.hashCode(), and Object.toString(). These methods may be used, for example, by Java compiler implementations to implement the bodies of Object methods for record classes.

Since:

16

Method Summary

Modifier and Type	Method	Description
static Object	bootstrap(MethodHandles.Lookup lookup, String methodName, TypeDescriptor type, Class<?> recordClass, String names, MethodHandle... getters)	Bootstrap method to generate the Object.equals(Object), Object.hashCode(), and Object.toString() methods, based on a description of the component names and accessor methods, for either invokedynamic call sites or dynamic constant pool entries.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for 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.
String	toString()	Returns a string representation of the object.
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.

Method Details

bootstrap

public static Object bootstrap(MethodHandles.Lookup lookup,
 String methodName,
 TypeDescriptor type,
 Class<?> recordClass,
 String names,
 MethodHandle... getters)
                        throws Throwable

Bootstrap method to generate the Object.equals(Object), Object.hashCode(), and Object.toString() methods, based on a description of the component names and accessor methods, for either invokedynamic call sites or dynamic constant pool entries. For more detail on the semantics of the generated methods see the specification of Record.equals(Object), Record.hashCode() and Record.toString().

Parameters:

lookup - Every bootstrap method is expected to have a lookup which usually represents a lookup context with the accessibility privileges of the caller. This is because invokedynamic call sites always provide a lookup to the corresponding bootstrap method, but this method just ignores the lookup parameter

methodName - the name of the method to generate, which must be one of "equals", "hashCode", or "toString"

type - a MethodType corresponding the descriptor type for the method, which must correspond to the descriptor for the corresponding Object method, if linking an invokedynamic call site, or the constant MethodHandle.class, if linking a dynamic constant

recordClass - the record class hosting the record components

names - the list of component names, joined into a string separated by ";", or the empty string if there are no components. This parameter is ignored if the methodName parameter is "equals" or "hashCode"

getters - method handles for the accessor methods for the components

Returns:

a call site if invoked by indy, or a method handle if invoked by a condy

Throws:

IllegalArgumentException - if the bootstrap arguments are invalid or inconsistent

NullPointerException - if any argument is null or if any element in the getters array is null

Throwable - if any exception is thrown during call site construction