Module java.base
Package java.lang.runtime

Class ObjectMethods

java.lang.Object
java.lang.runtime.ObjectMethods
public 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 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