Class ELMethods

java.lang.Object

io.micronaut.el.runtime.ELMethods

@Internal
public final class ELMethods
extends Object

Selects the method a method expression refers to, as described in the section 1.6 of the Jakarta Expression Language specification.

When the parameter types are provided at parse time they select the method on their own. Otherwise the evaluated arguments are used: an exact match is preferred over an assignable one, an assignable one over a coercible one, and a method with a fixed arity over a variable arity method. A tie makes the reference ambiguous, which is an error.

Since:

1.0

Author:

Denis Stepanov

Method Summary

Modifier and Type	Method	Description
static Method	accessible(Method method)	Returns a declaration of the method that can be invoked reflectively.
static Method	findMethod(Class<?> type, String name, Class<?> @Nullable [] paramTypes, Object @Nullable [] arguments)	Finds the method a method expression refers to.
static @Nullable Method	findMethodOrNull(Class<?> type, String name, Class<?> @Nullable [] paramTypes, Object @Nullable [] arguments, boolean isStatic)	Finds a method by name and arguments, as findMethod(Class, String, Class[], Object[]) does, or returns null when the type declares no public method of the name.
static @Nullable Object	invoke(jakarta.el.ELContext context, Method method, @Nullable Object base, Object @Nullable [] values)	Invokes a method reflectively, the arguments coerced to the parameter types as described in the section 1.23 of the specification, the variable arity arguments packed into an array, the exceptions of the method unwrapped.

Methods inherited from class Object

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

Method Details

findMethodOrNull

public static @Nullable Method findMethodOrNull(Class<?> type,
 String name,
 Class<?> @Nullable [] paramTypes,
 Object @Nullable [] arguments,
 boolean isStatic)

Finds a method by name and arguments, as findMethod(Class, String, Class[], Object[]) does, or returns null when the type declares no public method of the name.

Parameters:

type - The type of the base object, or the class for a static method

name - The name of the method

paramTypes - The parameter types provided at parse time, can be null

arguments - The evaluated arguments, can be null

isStatic - Whether to look for a static method

Returns:

The method, or null when the type declares no method of the name

invoke

public static @Nullable Object invoke(jakarta.el.ELContext context,
 Method method,
 @Nullable Object base,
 Object @Nullable [] values)

Invokes a method reflectively, the arguments coerced to the parameter types as described in the section 1.23 of the specification, the variable arity arguments packed into an array, the exceptions of the method unwrapped.

Parameters:

context - The context

method - The method

base - The base object, or null for a static method

values - The arguments

Returns:

The result of the invocation

findMethod

public static Method findMethod(Class<?> type,
 String name,
 Class<?> @Nullable [] paramTypes,
 Object @Nullable [] arguments)

Finds the method a method expression refers to.

Parameters:

type - The type of the base object

name - The name of the method

paramTypes - The parameter types provided at parse time, can be null

arguments - The evaluated arguments, can be null

Returns:

The method

accessible

public static Method accessible(Method method)

Returns a declaration of the method that can be invoked reflectively.

Class.getMethods() returns the method as declared on the runtime class, which may not be accessible: the lists of List.of, the views of Collections and lambdas all implement public interfaces from classes that are not public. The public declaration is found on a supertype, which is what jakarta.el.ELUtil does for the standard resolvers.

Parameters:

method - The method as declared on the runtime class

Returns:

An accessible declaration of the same method