com.atlassian.utt.reflect

Class ReflectionFunctions

java.lang.Object

com.atlassian.utt.reflect.ReflectionFunctions

public class ReflectionFunctions
extends Object

Factories for functions that call a method of a class, or access a field. These return NamedFunctions which can easily be transformed into matchers.

As with all reflection-based code, you will not get a compile-time error if you specify the wrong name for a the method or field. However, it will at least fail fast at runtime, throwing an error as soon as you try to construct the invalid function.

Example:

     
     // a Function<Person, String> that calls person.getFirstName()
     accessor(Person.class, String.class, "getFirstName");
     accessor(Person.class, String.class, "firstName");  // standard bean accessor naming is assumed

     // a Function<Person, Iterable<String>> that calls person.getChildren()
     iterableAccessor(Person.class, String.class, "getChildren");

     // a Matcher<Person> that is equivalent to assertThat(person.getFirstName(), equalTo("Bob"))
     // (the matcher will self-describe as 'firstName "Bob"')
     accessor(Person.class, String.class, "getFirstName").is(equalTo("Bob"))
     
  

Since:

0.0.4

Constructor Summary

Constructors

Constructor and Description
ReflectionFunctions()

Method Summary

Modifier and Type	Method and Description
static <A,B> NamedFunction<A,B>	accessor(Class<A> objectClass, Class<B> returnClass, String name) Using reflection, returns a NamedFunction that will call a zero-argument method on its target, or get the value of a field.
static <A,B> NamedFunction<A,Iterable<B>>	iterableAccessor(Class<A> objectClass, Class<B> returnElementClass, String name) Similar to accessor(Class, Class, String), but for methods or fields with an Iterable type.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReflectionFunctions

public ReflectionFunctions()

Method Detail

accessor

public static <A,B> NamedFunction<A,B> accessor(Class<A> objectClass,
                                                Class<B> returnClass,
                                                String name)

Using reflection, returns a NamedFunction that will call a zero-argument method on its target, or get the value of a field. It will try to find the following, in order: 1. a method with the exact name specified ("xxx()"); 2. a method with a standard bean method prefix ("getXxx()" or "isXxx()"); 3. a field with the exact name specified.

Parameters:

objectClass - class of the target

returnClass - type of the method's return value or the field's value

name - name of the method or field

Returns:

a function

Throws:

IllegalArgumentException - if no such method/field exists or it has the wrong return type

iterableAccessor

public static <A,B> NamedFunction<A,Iterable<B>> iterableAccessor(Class<A> objectClass,
                                                                  Class<B> returnElementClass,
                                                                  String name)

Similar to accessor(Class, Class, String), but for methods or fields with an Iterable type. (This is separate from accessor(Class, Class, String) because parameterized types require special handling.)

Parameters:

objectClass - class of the target

returnElementClass - type of the elements in the Iterable returned by the method or field

name - name of the method or field (follows same rules as accessor)

Returns:

a function

Throws:

IllegalArgumentException - if no such method or field exists or it has the wrong return type