#13 spring db: querydsl - basic

spring-db/src/main/java/hello/itemservice/ItemServiceApplication.java

@@ -19,7 +19,8 @@ import javax.sql.DataSource;
 //@Import(JdbcTemplateV3Config.class)
 //@Import(MyBatisConfig.class)
 //@Import(JpaConfig.class)
-@Import(SpringDataJpaConfig.class)
+//@Import(SpringDataJpaConfig.class)
+@Import(QuerydslConfig.class)
 @SpringBootApplication(scanBasePackages = "hello.itemservice.web")
 public class ItemServiceApplication {
 

spring-db/src/main/java/hello/itemservice/config/QuerydslConfig.java

@@ -0,0 +1,28 @@
+package hello.itemservice.config;
+
+import hello.itemservice.repository.ItemRepository;
+import hello.itemservice.repository.jpa.JpaItemRepositoryV3;
+import hello.itemservice.service.ItemService;
+import hello.itemservice.service.ItemServiceV1;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.persistence.EntityManager;
+
+@Configuration
+@RequiredArgsConstructor
+public class QuerydslConfig {
+
+    private final EntityManager em;
+
+    @Bean
+    public ItemService itemService() {
+        return new ItemServiceV1(itemRepository());
+    }
+
+    @Bean
+    public ItemRepository itemRepository() {
+        return new JpaItemRepositoryV3(em);
+    }
+}

spring-db/src/main/java/hello/itemservice/repository/jpa/JpaItemRepositoryV3.java

@@ -0,0 +1,104 @@
+package hello.itemservice.repository.jpa;
+
+import com.querydsl.core.BooleanBuilder;
+import com.querydsl.core.types.Predicate;
+import com.querydsl.core.types.dsl.BooleanExpression;
+import com.querydsl.jpa.impl.JPAQueryFactory;
+import hello.itemservice.domain.Item;
+import hello.itemservice.domain.QItem;
+import hello.itemservice.repository.ItemRepository;
+import hello.itemservice.repository.ItemSearchCond;
+import hello.itemservice.repository.ItemUpdateDto;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Repository;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.util.StringUtils;
+
+import javax.persistence.EntityManager;
+import java.util.List;
+import java.util.Optional;
+
+import static hello.itemservice.domain.QItem.*;
+
+@Repository
+@Transactional
+@RequiredArgsConstructor
+public class JpaItemRepositoryV3 implements ItemRepository {
+
+    private final EntityManager em;
+    private final JPAQueryFactory query;
+
+    public JpaItemRepositoryV3(EntityManager em) {
+        this.em = em;
+        this.query = new JPAQueryFactory(em);
+    }
+
+    @Override
+    public Item save(Item item) {
+        em.persist(item);
+        return item;
+    }
+
+    @Override
+    public void update(Long itemId, ItemUpdateDto updateParam) {
+        Item findItem = em.find(Item.class, itemId);
+
+        findItem.setItemName(updateParam.getItemName());
+        findItem.setPrice(updateParam.getPrice());
+        findItem.setQuantity(updateParam.getQuantity());
+    }
+
+    @Override
+    public Optional<Item> findById(Long id) {
+        Item item = em.find(Item.class, id);
+
+        return Optional.ofNullable(item);
+    }
+
+    public List<Item> findAllOld(ItemSearchCond cond) {
+
+        String itemName = cond.getItemName();
+        Integer maxPrice = cond.getMaxPrice();
+
+        BooleanBuilder builder = new BooleanBuilder();
+        if (StringUtils.hasText(itemName)) {
+            builder.and(item.itemName.like("%" + itemName + "%"));
+        }
+        if (maxPrice != null) {
+            builder.and(item.price.loe(maxPrice));
+        }
+
+        return query
+                .select(item)
+                .from(item)
+                .where(builder)
+                .fetch();
+    }
+
+    @Override
+    public List<Item> findAll(ItemSearchCond cond) {
+
+        String itemName = cond.getItemName();
+        Integer maxPrice = cond.getMaxPrice();
+
+        return query
+                .select(item)
+                .from(item)
+                .where(likeItemName(itemName), maxPrice(maxPrice))
+                .fetch();
+    }
+
+    private BooleanExpression likeItemName(String itemName) {
+        if (StringUtils.hasText(itemName)) {
+            return item.itemName.like("%" + itemName + "%");
+        }
+        return null;
+    }
+
+    private BooleanExpression maxPrice(Integer maxPrice) {
+        if (maxPrice != null) {
+            return item.price.loe(maxPrice);
+        }
+        return null;
+    }
+}