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()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

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 - the full-privilege lookup context of the caller

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

Throwable - if any exception is thrown during call site construction