Fixed #10 Implemented custom mappers

RELEASE_NOTES.md

@@ -1,3 +1,7 @@
+# 1.0.4
+
+* Added custom mappers
+
 # 1.0.3
 
 * Managed Set

src/main/java/com/joanzapata/mapper/CustomMapperWrapper.java

@@ -10,19 +10,30 @@ class CustomMapperWrapper<S, D> {
         this.customMapper = customMapper;
     }
 
-    public D apply(Object source, Class destination) {
-        for (Method method : customMapper.getClass().getMethods()) {
+    public boolean isApplicable(Object source, Class destination) {
+        final Method[] methods = customMapper.getClass().getMethods();
+
+        for (Method method : methods) {
             if ("map".equals(method.getName())) {
-                Class<?>[] parameterTypes = method.getParameterTypes();
-                Class<?> sourceClass = parameterTypes[0];
-                Class<?> destinationClass = method.getReturnType();
-                if (sourceClass.isAssignableFrom(source.getClass()) &&
-                        destinationClass.isAssignableFrom(destination)) {
-                    return applySafe((S) source);
+                Class<?> parameterType = method.getParameterTypes()[0];
+                Class<?> returnType = method.getReturnType();
+                // Ignore Object because it's too large
+                if (parameterType != Object.class && returnType != Object.class &&
+                        // Parameter type of the user function will be assigned the source object
+                        parameterType.isAssignableFrom(source.getClass()) &&
+                        // The destination object will be assigned the object returned from user function
+                        destination.isAssignableFrom(returnType)) {
+                    return true;
                 }
             }
         }
-        return null;
+        return false;
+    }
+
+    public D apply(S source, Class<D> destination) {
+        if (isApplicable(source, destination)) {
+            return applySafe((S) source);
+        } else return null;
     }
 
     private D applySafe(S source) {

src/main/java/com/joanzapata/mapper/Mapper.java

@@ -162,7 +162,8 @@ CD mapCollection(CU source, Class<D> destinationClass, MappingContext context) {
             } else return null;
         }
         for (Object s : source) {
-            out.add(nominalMap(s, destinationClass, context));
+            final D mappedElement = nominalMap(s, destinationClass, context);
+            if (mappedElement != null) out.add(mappedElement);
         }
         return out;
     }
@@ -229,6 +230,10 @@ private <D> D nominalMap(Object source, Type field, Class<D> destinationClass, M
             return alreadyMapped;
         }
 
+        // Try to find appropriate customMapper if any
+        CustomMapperResult<D> customMapperResult = MapperUtil.applyCustomMappers(customMappers, source, destinationClass);
+        if (customMapperResult.hasMatched) return customMapperResult.result;
+
         // Map native types if possible
         D nativeMapped = mapPrimitiveTypeOrNull(source);
         if (nativeMapped != null) {
@@ -311,4 +316,17 @@ private <D> D nominalMap(Object source, Type field, Class<D> destinationClass, M
         return destinationInstance;
     }
 
+    public static class CustomMapperResult<T> {
+        boolean hasMatched = false;
+        T result = null;
+
+        // Success
+        public CustomMapperResult(T result) {
+            this.result = result;
+            this.hasMatched = true;
+        }
+
+        // Fail
+        public CustomMapperResult() {}
+    }
 }

src/main/java/com/joanzapata/mapper/MapperUtil.java

@@ -20,20 +20,11 @@
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
-final class MapperUtil {
-
-    public static final Collection createCollectionLike(Collection source) {
-        return new ArrayList();
-    }
+import static com.joanzapata.mapper.Mapper.CustomMapperResult;
 
-    public static final Map createMapLike(Map source) {
-        return new HashMap();
-    }
+final class MapperUtil {
 
     /**
      * Find a getter on the source object for the given setter name.
@@ -153,4 +144,18 @@ public static void applyHooks(List<HookWrapper> hooks, Object source, Object des
             hook.apply(source, destination);
         }
     }
+
+    @SuppressWarnings("unchecked")
+    public static <D> CustomMapperResult<D> applyCustomMappers(List<CustomMapperWrapper> customMappers, Object source, Class<D> destinationClass) {
+        for (CustomMapperWrapper customMapper : customMappers) {
+            if (customMapper.isApplicable(source, destinationClass)) {
+                // Mapped has applied
+                final D destination = (D) customMapper.apply(source, destinationClass);
+                return new CustomMapperResult(destination);
+            }
+        }
+        // Mapped has not applied
+        return new CustomMapperResult();
+
+    }
 }

src/test/java/com/joanzapata/mapper/MapperTest.java

@@ -48,14 +48,24 @@ public class MapperTest {
 
     @Test
     public void singleObjectWithCustomMapperToNull() {
-        Mapper mapper = new Mapper().customMapper(new CustomMapperToNull<Book, BookDTO>());
+        Mapper mapper = new Mapper().customMapper(new CustomMapper<Book, BookDTO>() {
+            @Override
+            public BookDTO map(Book source) {
+                return null;
+            }
+        });
         Book book = new Book(5L, "Book");
         assertNull(mapper.map(book, BookDTO.class));
     }
 
     @Test
     public void objectListWithCustomMapperToNull() {
-        Mapper mapper = new Mapper().customMapper(new CustomMapperToNull<Book, BookDTO>());
+        Mapper mapper = new Mapper().customMapper(new CustomMapper<Book, BookDTO>() {
+            @Override
+            public BookDTO map(Book source) {
+                return null;
+            }
+        });
         Book b1 = new Book(1L, "Book1");
         Book b2 = new Book(2L, "Book2");
         Book b3 = new Book(3L, "Book3");
@@ -66,15 +76,29 @@ public void objectListWithCustomMapperToNull() {
 
     @Test
     public void singleObjectWithCustomMapperToFixed() {
-        Mapper mapper = new Mapper().customMapper(new CustomMapperToFixed<Book>("Fixed"));
+        Mapper mapper = new Mapper().customMapper(new CustomMapper<Book, BookDTO>() {
+            @Override
+            public BookDTO map(Book source) {
+                final BookDTO bookDTO = new BookDTO();
+                bookDTO.setName("Fixed");
+                return bookDTO;
+            }
+        });
         Book book = new Book(5L, "Book");
         final BookDTO bookDto = mapper.map(book, BookDTO.class);
         assertEquals("Fixed", bookDto.getName());
     }
 
     @Test
     public void objectListWithCustomMapperToFixed() {
-        Mapper mapper = new Mapper().customMapper(new CustomMapperToFixed<Book>("Fixed"));
+        Mapper mapper = new Mapper().customMapper(new CustomMapper<Book, BookDTO>() {
+            @Override
+            public BookDTO map(Book source) {
+                final BookDTO bookDTO = new BookDTO();
+                bookDTO.setName("Fixed");
+                return bookDTO;
+            }
+        });
         Book b1 = new Book(1L, "Book1");
         Book b2 = new Book(2L, "Book2");
         Book b3 = new Book(3L, "Book3");
@@ -129,14 +153,14 @@ public void inheritanceWithUncalledCustomMapper() {
         Mapper mapper = new Mapper()
                 .mapping(AddressEntry.class, AddressEntryDTO.class)
                 .mapping(PhoneEntry.class, PhoneEntryDTO.class)
-                .customMapper(new CustomMapper<PhoneEntry, AddressEntryDTO>() {
+                .customMapper(new CustomMapper<PhoneEntry, Object>() {
                     @Override
-                    public AddressEntryDTO map(PhoneEntry source) {
+                    public Object map(PhoneEntry source) {
                         fail("Shouldn't call this mapper");
                         return null;
                     }
                 });
-        BookDTO bookDTO = mapper.map(book, BookDTO.class);
+        mapper.map(book, BookDTO.class);
     }
 
     @Test
@@ -481,25 +505,4 @@ public void setTestOtherDTO(String testOtherDTO) {
         }
     }
 
-    public static class CustomMapperToNull<S, D> implements CustomMapper<S, D> {
-        @Override
-        public D map(S source) {
-            return null;
-        }
-    }
-
-    public class CustomMapperToFixed<S> implements CustomMapper<S, BookDTO> {
-        private String fixed;
-
-        public CustomMapperToFixed(String fixed) {
-            this.fixed = fixed;
-        }
-
-        @Override
-        public BookDTO map(S source) {
-            final BookDTO bookDTO = new BookDTO();
-            bookDTO.setName(fixed);
-            return bookDTO;
-        }
-    }
 }