feat(ContainerMethod): @ContainerMethod supports extracting actual da…

…ta from specified properties in the wrapper class (GitHub #266)

crane4j-annotation/src/main/java/cn/crane4j/annotation/ContainerMethod.java

@@ -111,6 +111,32 @@
      */
     Class<?>[] bindMethodParamTypes() default {};
 
+    /**
+     * <p>When the return value is a wrapper class,
+     * we can specify to obtain the dataset to be processed
+     * from the specific field of the wrapper class,
+     * and then use it to be data source of the container.
+     *
+     * <p>For example:
+     * <pre type="code">{@code
+     * // general response
+     * public static class Result<T> {
+     *     private Integer code;
+     *     private T data; // objects to be processed
+     * }
+     * // process general response
+     * @ContainerMethod(resultType = Foo.class, on = "data")
+     * public Result<List<Foo>> requestFoo() { // do something }
+     * }</pre>
+     * The return value of the method is<i>Result</i>, but the data is in <i>Result.data</i>,
+     * obtain data from specific fields for <i>on</i>.
+     *
+     * @return field name
+     * @since 2.8.0
+     * @see AutoOperate#on()
+     */
+    String on() default "";
+
     /**
      * Batch operation.
      *

crane4j-core/src/main/java/cn/crane4j/core/container/MethodInvokerContainer.java

@@ -6,6 +6,8 @@
 import cn.crane4j.core.util.CollectionUtils;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.util.Collection;
@@ -14,6 +16,7 @@
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 /**
@@ -56,6 +59,25 @@ public abstract class MethodInvokerContainer implements Container<Object> {
     @Nullable
     protected final Object target;
 
+    /**
+     * The extractor will be used to extract the data from the wrapped object.
+     */
+    @Setter
+    @Nullable
+    protected MethodInvoker extractor;
+
+    /**
+     * extract data from the result if possible.
+     *
+     * @param result result
+     * @return extracted data
+     * @since 2.8.0
+     */
+    @Nullable
+    protected Object extractIfPossible(@NonNull Object result) {
+        return Objects.nonNull(extractor) ? extractor.invoke(result) : result;
+    }
+
     /**
      * Create a standard method data source container.
      *
@@ -139,10 +161,10 @@ public SingleKey(String namespace, MethodInvoker methodInvoker, @Nullable Object
         @Override
         public Map<Object, ?> get(Collection<Object> keys) {
             Map<Object, Object> results = new HashMap<>(keys.size());
-            keys.forEach(key -> {
-                Object result = methodInvoker.invoke(target, key);
-                results.put(key, result);
-            });
+            keys.forEach(key -> Optional.ofNullable(methodInvoker.invoke(target, key))
+                .map(this::extractIfPossible)
+                .ifPresent(result -> results.put(key, result))
+            );
             return results;
         }
     }
@@ -167,11 +189,10 @@ public StandardMethodInvokerContainer(String namespace, MethodInvoker methodInvo
         @Override
         public Map<Object, ?> get(Collection<Object> keys) {
             Object[] arguments = resolveArguments(keys);
-            Object result = methodInvoker.invoke(target, arguments);
-            if (Objects.isNull(result)) {
-                return Collections.emptyMap();
-            }
-            return resolveResult(keys, result);
+            return Optional.ofNullable(methodInvoker.invoke(target, arguments))
+                .map(this::extractIfPossible)
+                .map(result -> resolveResult(keys, result))
+                .orElse(Collections.emptyMap());
         }
 
         /**

crane4j-core/src/main/java/cn/crane4j/core/support/container/DefaultMethodContainerFactory.java

@@ -81,9 +81,16 @@ public List<Container<Object>> get(
     }
 
     private Container<Object> createContainer(Object source, Method method, ContainerMethod annotation) {
-        return methodInvokerContainerCreator.createContainer(
-            source, method, annotation.type(), annotation.namespace(),
-            annotation.resultType(), annotation.resultKey(), annotation.duplicateStrategy()
-        );
+        MethodInvokerContainerCreator.MethodInvokerContainerCreation containerCreation = MethodInvokerContainerCreator.MethodInvokerContainerCreation.builder()
+            .target(source)
+            .method(method)
+            .mappingType(annotation.type())
+            .namespace(annotation.namespace())
+            .resultType(annotation.resultType())
+            .resultKey(annotation.resultKey())
+            .duplicateStrategy(annotation.duplicateStrategy())
+            .on(annotation.on())
+            .build();
+        return methodInvokerContainerCreator.createContainer(containerCreation);
     }
 }

crane4j-core/src/main/java/cn/crane4j/core/support/container/MethodInvokerContainerCreator.java

@@ -23,6 +23,7 @@
 import java.util.Collection;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 
 /**
  * Support class for {@link MethodInvokerContainer} creation.
@@ -39,69 +40,37 @@ public class MethodInvokerContainerCreator {
     protected final PropertyOperator propertyOperator;
     protected final ConverterManager converterManager;
 
-    /**
-     * Create a {@link MethodInvokerContainer} from the given method.
-     *
-     * @param target method's calling object, if the method is static, it can be null
-     * @param method method
-     * @param mappingType mapping type
-     * @param namespace namespace, if null, use method name as namespace
-     * @param resultType result type
-     * @param resultKey result key
-     * @param duplicateStrategy duplicate strategy
-     * @return {@link MethodInvokerContainer}
-     */
-    public MethodInvokerContainer createContainer(
-        @Nullable Object target, Method method, MappingType mappingType,
-        @Nullable String namespace, Class<?> resultType, String resultKey, DuplicateStrategy duplicateStrategy) {
-        log.debug("create method container from [{}]", method);
-        MethodInvokerContainerCreation containerCreation = MethodInvokerContainerCreation.builder()
-            .target(target)
-            .method(method)
-            .methodInvoker(getMethodInvoker(target, method))
-            .mappingType(mappingType)
-            .namespace(namespace)
-            .resultType(resultType)
-            .resultKey(resultKey)
-            .duplicateStrategy(duplicateStrategy)
-            .build();
-        return doCreateContainer(containerCreation);
-    }
-
-    /**
-     * Create a {@link MethodInvokerContainer} from the given method.
-     *
-     * @param target method's calling object, if the method is static, it can be null
-     * @param methodInvoker method invoker
-     * @param mappingType mapping type
-     * @param namespace namespace, if null, use method name as namespace
-     * @param resultType result type
-     * @param resultKey result key
-     * @param duplicateStrategy duplicate strategy
-     * @return {@link MethodInvokerContainer}
-     */
     public MethodInvokerContainer createContainer(
-        @Nullable Object target, MethodInvoker methodInvoker, MappingType mappingType,
-        @Nullable String namespace, Class<?> resultType, String resultKey, DuplicateStrategy duplicateStrategy) {
-        MethodInvokerContainerCreation containerCreation = MethodInvokerContainerCreation.builder()
-            .target(target)
-            .methodInvoker(methodInvoker)
-            .mappingType(mappingType)
-            .namespace(namespace)
-            .resultType(resultType)
-            .resultKey(resultKey)
-            .duplicateStrategy(duplicateStrategy)
-            .build();
-        return doCreateContainer(containerCreation);
-    }
-
-    private MethodInvokerContainer doCreateContainer(MethodInvokerContainerCreation containerCreation) {
+        MethodInvokerContainerCreation containerCreation) {
+        Object target = containerCreation.getTarget();
         Method method = containerCreation.getMethod();
         String namespace = getNamespace(method, containerCreation.getNamespace());
         MappingType mappingType = containerCreation.getMappingType();
-        MethodInvoker methodInvoker = containerCreation.getMethodInvoker();
-        Object target = containerCreation.getTarget();
+        MethodInvoker methodInvoker = Optional.ofNullable(containerCreation.getMethodInvoker())
+            .orElseGet(() -> adaptMethodToInvoker(target, method));
+
+        MethodInvokerContainer container = doCreateContainer(
+            containerCreation, mappingType, target, methodInvoker, method, namespace);
+
+        // https://github.com/opengoofy/crane4j/issues/266
+        String extractProperty = containerCreation.getOn();
+        if (StringUtils.isNotEmpty(extractProperty)) {
+            MethodInvoker extractor = (t, args) ->
+                propertyOperator.readProperty(t.getClass(), t, extractProperty);
+            container.setExtractor(extractor);
+        }
+
+        if (Objects.isNull(method)) {
+            log.info("create method invoker container [{}], mapping type is [{}]", container.getNamespace(), mappingType);
+        } else {
+            log.info("create method invoker container [{}] for method [{}], mapping type is [{}]", container.getNamespace(), method, mappingType);
+        }
+        return container;
+    }
 
+    private MethodInvokerContainer doCreateContainer(
+        MethodInvokerContainerCreation containerCreation, MappingType mappingType,
+        Object target, MethodInvoker methodInvoker, Method method, String namespace) {
         MethodInvokerContainer container;
         if (mappingType == MappingType.NO_MAPPING) {
             container = doCreateNoMappingContainer(target, methodInvoker, method, namespace);
@@ -112,26 +81,18 @@ private MethodInvokerContainer doCreateContainer(MethodInvokerContainerCreation
                 doCreateSingleKeyContainer(target, methodInvoker, namespace) :
                 doCreateOrderOfKeysContainer(target, methodInvoker, method, namespace);
         } else if (mappingType == MappingType.ONE_TO_ONE) {
-            container = doCreateOneToOneContainer(
-                target, methodInvoker, method, namespace,
+            container = doCreateOneToOneContainer(target, methodInvoker, method, namespace,
                 containerCreation.getResultType(), containerCreation.getResultKey(),
                 containerCreation.getDuplicateStrategy()
             );
         } else if (mappingType == MappingType.ONE_TO_MANY) {
-            container = doCreateOneToManyContainer(
-                target, methodInvoker, method, namespace,
+            container = doCreateOneToManyContainer(target, methodInvoker, method, namespace,
                 containerCreation.getResultType(), containerCreation.getResultKey(),
                 containerCreation.getDuplicateStrategy()
             );
         } else {
             throw new Crane4jException("unsupported mapping type: " + mappingType);
         }
-
-        if (Objects.isNull(method)) {
-            log.debug("create method invoker container [{}], mapping type is [{}]", container.getNamespace(), mappingType);
-        } else {
-            log.debug("create method invoker container [{}] for method [{}], mapping type is [{}]", container.getNamespace(), method, mappingType);
-        }
         return container;
     }
 
@@ -188,7 +149,7 @@ protected MethodInvokerContainer doCreateOneToManyContainer(
      * otherwise invoke method on target object
      */
     @NonNull
-    protected MethodInvoker getMethodInvoker(Object target, Method method) {
+    protected MethodInvoker adaptMethodToInvoker(Object target, Method method) {
         MethodInvoker invoker = ReflectiveMethodInvoker.create(target, method, false);
         return ParameterConvertibleMethodInvoker.create(invoker, converterManager, method.getParameterTypes());
     }
@@ -255,7 +216,7 @@ protected MethodInvoker findKeyGetter(Class<?> resultType, String resultKey) {
 
     @Getter
     @Builder
-    private static class MethodInvokerContainerCreation {
+    public static class MethodInvokerContainerCreation {
         @Nullable
         private final Object target;
         @Nullable
@@ -267,5 +228,7 @@ private static class MethodInvokerContainerCreation {
         private final Class<?> resultType;
         private final String resultKey;
         private final DuplicateStrategy duplicateStrategy;
+        @Nullable
+        private final String on;
     }
 }

crane4j-core/src/main/java/cn/crane4j/core/support/container/query/AbstractQueryContainerProvider.java

@@ -166,12 +166,18 @@ private Container<?> createQueryContainer(String namespace) {
     private MethodInvokerContainer doCreateContainer(
             String namespace, String keyProperty, Repository<T> repository, QueryInfo queryInfo, Set<String> queryColumns, String keyColumn) {
         MethodInvoker methodInvoker = createMethodInvoker(
-                namespace, repository, queryColumns, keyColumn, keyProperty
-        );
-        return methodInvokerContainerCreator.createContainer(
-            repository.getTarget(), methodInvoker, queryInfo.getMappingType(),
-            namespace, repository.getEntityType(), keyProperty, DuplicateStrategy.ALERT
+            namespace, repository, queryColumns, keyColumn, keyProperty
         );
+        MethodInvokerContainerCreator.MethodInvokerContainerCreation containerCreation = MethodInvokerContainerCreator.MethodInvokerContainerCreation.builder()
+            .target(repository.getTarget())
+            .methodInvoker(methodInvoker)
+            .mappingType(queryInfo.getMappingType())
+            .namespace(namespace)
+            .resultType(repository.getEntityType())
+            .resultKey(keyProperty)
+            .duplicateStrategy(DuplicateStrategy.ALERT)
+            .build();
+        return methodInvokerContainerCreator.createContainer(containerCreation);
     }
 
     /**

crane4j-core/src/test/java/cn/crane4j/core/container/MethodInvokerContainerTest.java

@@ -4,6 +4,7 @@
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
+import lombok.RequiredArgsConstructor;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -110,6 +111,20 @@ public void getWhenNotKeyExtractor() {
         Assert.assertEquals(foo2, map.get("1"));
     }
 
+    @Test
+    public void getWhenWrapper() {
+        MethodInvokerContainer container = MethodInvokerContainer.oneToOne(
+            MethodInvokerContainer.class.getSimpleName(),
+            (t, arg) -> service.wrapperMethod((Collection<String>)arg[0]),
+            service, t -> ((Foo) t).key, DuplicateStrategy.ALERT
+        );
+        container.setExtractor((t, args) -> ((Result<Collection<Foo>>)t).getData());
+        Assert.assertEquals(MethodInvokerContainer.class.getSimpleName(), container.getNamespace());
+        Map<Object, ?> map = container.get(Arrays.asList("2", "1"));
+        Assert.assertEquals(foo1, map.get("1"));
+        Assert.assertEquals(foo2, map.get("2"));
+    }
+
     @AllArgsConstructor
     @EqualsAndHashCode
     @Getter
@@ -128,5 +143,14 @@ public Map<String, Foo> mappedMethod(Collection<String> key) {
         public List<Foo> noneMappedMethod(Collection<String> key) {
             return Objects.isNull(key) ? null : Arrays.asList(foo1, foo2);
         }
+        public Result<Collection<Foo>> wrapperMethod(Collection<String> key) {
+            return new Result<>(Arrays.asList(foo1, foo2));
+        }
+    }
+
+    @Getter
+    @RequiredArgsConstructor
+    public static class Result<T> {
+        private final T data;
     }
 }