Fix super class의 필드 접근 못하는 이슈 해결

spring-batch-querydsl-integration-test/src/main/java/org/springframework/batch/item/querydsl/integrationtest/entity/EntityAuditing.java

@@ -0,0 +1,21 @@
+package org.springframework.batch.item.querydsl.integrationtest.entity;
+
+import javax.persistence.EntityListeners;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.MappedSuperclass;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
+
+@EntityListeners(AuditingEntityListener.class)
+@MappedSuperclass
+abstract class EntityAuditing {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    public Long getId() {
+        return id;
+    }
+}

spring-batch-querydsl-integration-test/src/main/java/org/springframework/batch/item/querydsl/integrationtest/entity/Foo.java

@@ -0,0 +1,20 @@
+package org.springframework.batch.item.querydsl.integrationtest.entity;
+
+import javax.persistence.Entity;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+
+@Entity
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@Getter
+public class Foo extends EntityAuditing {
+
+
+    private String name;
+
+    public Foo(String name) {
+        this.name = name;
+    }
+}

spring-batch-querydsl-integration-test/src/main/java/org/springframework/batch/item/querydsl/integrationtest/entity/FooRepository.java

@@ -0,0 +1,6 @@
+package org.springframework.batch.item.querydsl.integrationtest.entity;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface FooRepository extends JpaRepository<Foo, Long> {
+}

spring-batch-querydsl-integration-test/src/test/java/org/springframework/batch/item/querydsl/integrationtest/reader/QuerydslNoOffsetPagingItemReaderGroupByTest.java

@@ -1,39 +1,46 @@
 package org.springframework.batch.item.querydsl.integrationtest.reader;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.batch.item.querydsl.integrationtest.entity.QFoo.foo;
+import static org.springframework.batch.item.querydsl.integrationtest.entity.QManufacture.manufacture;
+
+import java.time.LocalDate;
+import javax.persistence.EntityManagerFactory;
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.batch.item.ExecutionContext;
 import org.springframework.batch.item.querydsl.integrationtest.TestBatchConfig;
+import org.springframework.batch.item.querydsl.integrationtest.entity.Foo;
+import org.springframework.batch.item.querydsl.integrationtest.entity.FooRepository;
 import org.springframework.batch.item.querydsl.integrationtest.entity.Manufacture;
 import org.springframework.batch.item.querydsl.integrationtest.entity.ManufactureRepository;
 import org.springframework.batch.item.querydsl.integrationtest.job.QuerydslNoOffsetPagingItemReaderConfiguration;
 import org.springframework.batch.item.querydsl.reader.QuerydslNoOffsetPagingItemReader;
 import org.springframework.batch.item.querydsl.reader.expression.Expression;
+import org.springframework.batch.item.querydsl.reader.options.QuerydslNoOffsetNumberOptions;
 import org.springframework.batch.item.querydsl.reader.options.QuerydslNoOffsetStringOptions;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.test.context.junit4.SpringRunner;
 
-import javax.persistence.EntityManagerFactory;
-import java.time.LocalDate;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.springframework.batch.item.querydsl.integrationtest.entity.QManufacture.manufacture;
-
 @RunWith(SpringRunner.class)
 @SpringBootTest(classes = {TestBatchConfig.class, QuerydslNoOffsetPagingItemReaderConfiguration.class})
 public class QuerydslNoOffsetPagingItemReaderGroupByTest {
 
     @Autowired
     private ManufactureRepository manufactureRepository;
 
+    @Autowired
+    private FooRepository fooRepository;
+
     @Autowired
     private EntityManagerFactory emf;
 
     @After
     public void after() throws Exception {
         manufactureRepository.deleteAllInBatch();
+        fooRepository.deleteAllInBatch();
     }
 
     @Test
@@ -103,4 +110,27 @@ public void after() throws Exception {
         assertThat(read2.getName()).isEqualTo(expected1);
         assertThat(read3).isNull();
     }
-}
+
+    @Test
+    public void super_class의_필드_사용_가능하다() throws Exception {
+        //given
+        int chunkSize = 1;
+        final Long fooId = fooRepository.save(new Foo("foo1")).getId();
+
+        final QuerydslNoOffsetNumberOptions<Foo, Long> options = new QuerydslNoOffsetNumberOptions<>(foo.id, Expression.DESC);
+        final QuerydslNoOffsetPagingItemReader<Foo> reader = new QuerydslNoOffsetPagingItemReader<>(emf,
+            chunkSize,
+            options,
+            queryFactory -> queryFactory
+                .selectFrom(foo)
+                .where(foo.id.eq(fooId))
+        );
+        reader.open(new ExecutionContext());
+
+        //when
+        final Foo foo = reader.read();
+
+        //then
+        assertThat(foo.getId()).isEqualTo(fooId);
+    }
+}

spring-batch-querydsl-reader/src/main/java/org/springframework/batch/item/querydsl/reader/options/QuerydslNoOffsetOptions.java

@@ -41,7 +41,20 @@ public String getFieldName() {
 
     protected Object getFiledValue(T item) {
         try {
-            Field field = item.getClass().getDeclaredField(fieldName);
+            final Class<?> itemClass = item.getClass();
+            if (itemClass.getSuperclass() != null) {
+                final Class<?> superclass = itemClass.getSuperclass();
+                final Field[] superClassFields = superclass.getDeclaredFields();
+                for (Field field : superClassFields) {
+                    if (field.getName().equals(fieldName)) {
+                        field.setAccessible(true);
+                        superclass.getDeclaredField("id");
+                        return field.get(item);
+                    }
+                }
+            }
+
+            final Field field = itemClass.getDeclaredField("id");
             field.setAccessible(true);
             return field.get(item);
         } catch (NoSuchFieldException | IllegalAccessException e) {