Javadoc
An Expression that refers to a method on an object. The
ExpressionFactory#createMethodExpression(ELContext,String,Class,Class[]) method can be
used to parse an expression string and return a concrete instance of MethodExpression that
encapsulates the parsed expression. The
FunctionMapper is used at parse time, not
evaluation time, so one is not needed to evaluate an expression using this class. However, the
ELContext is needed at evaluation time. The
#getMethodInfo(ELContext) and
#invoke(ELContext,Object[]) methods will evaluate the expression each time they are
called. The
ELResolver in the ELContext is used to resolve the top-level variables and to
determine the behavior of the . and [] operators. For any of the two methods, the
ELResolver#getValue(ELContext,Object,Object) method is used to resolve all properties
up to but excluding the last one. This provides the base object on which the method appears. If
the base object is null, a PropertyNotFoundException must be thrown. At the last resolution, the
final property is then coerced to a String, which provides the name of the method to be found. A
method matching the name and expected parameters provided at parse time is found and it is either
queried or invoked (depending on the method called on this MethodExpression). See the notes about
comparison, serialization and immutability in the
Expression javadocs.