Package jakarta.el

Class MethodExpression

    • Constructor Detail

      • MethodExpression

        public MethodExpression()
    • Method Detail

      • getMethodInfo

        public abstract MethodInfo getMethodInfo​(ELContext context)
        Evaluates the expression relative to the provided context, and returns information about the actual referenced method.
        Parameters:
        context - The context of this evaluation
        Returns:
        an instance of MethodInfo containing information about the method the expression evaluated to.
        Throws:
        NullPointerException - if context is null
        PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.
        MethodNotFoundException - if no suitable method can be found.
        ELException - if an exception was thrown while performing property or variable resolution. The thrown exception must be included as the cause property of this exception, if available.
      • invoke

        public abstract Object invoke​(ELContext context,
                                      Object[] params)
        If a String literal is specified as the expression, returns the String literal coerced to the expected return type of the method signature. An ELException is thrown if expectedReturnType is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion" of the Jakarta Expression Language specification). If not a String literal, evaluates the expression relative to the provided context, invokes the method that was found using the supplied parameters, and returns the result of the method invocation. Any parameters passed to this method is ignored if isLiteralText() or isParametersProvided() is true.
        Parameters:
        context - The context of this evaluation.
        params - The parameters to pass to the method, or null if no parameters.
        Returns:
        the result of the method invocation (null if the method has a void return type).
        Throws:
        NullPointerException - if context is null
        PropertyNotFoundException - if one of the property resolutions failed because a specified variable or property does not exist or is not readable.
        MethodNotFoundException - if no suitable method can be found.
        ELException - if a String literal is specified and expectedReturnType of the MethodExpression is void or if the coercion of the String literal to the expectedReturnType yields an error (see Section "1.18 Type Conversion").
        ELException - if an exception was thrown while performing property or variable resolution. The thrown exception must be included as the cause property of this exception, if available. If the exception thrown is an InvocationTargetException, extract its cause and pass it to the ELException constructor.
      • isParametersProvided

        public boolean isParametersProvided()
        Return whether this MethodExpression was created with parameters.

        This method must return true if and only if parameters are specified in the EL, using the expr-a.expr-b(...) syntax.

        Returns:
        true if the MethodExpression was created with parameters, false otherwise.
        Since:
        Jakarta Expression Language 2.2
      • getMethodReference

        public MethodReference getMethodReference​(ELContext context)
        Obtain the MethodReference for the method to which this method expression resolves.
        Parameters:
        context - The EL context for this evaluation
        Returns:
        This default implementation always returns null
        Throws:
        NullPointerException - If the supplied context is null
        PropertyNotFoundException - If a property/variable resolution failed because no match was found or a match was found but was not readable
        MethodNotFoundException - If no matching method can be found
        ELException - Wraps any exception throw whilst resolving the property
        Since:
        EL 5.0