spring data jpa : paging(jpa)

spring-data-jpa/src/main/java/com/example/springdatajpa/repository/MemberJpaRepository.java

@@ -54,4 +54,18 @@ public class MemberJpaRepository {
                 .setParameter("username", username)
                 .getResultList();
     }
+
+    public List<Member> findByPage(int age, int offset, int limit) {
+        return em.createQuery("select m from Member m where m.age = :age order by m.username desc", Member.class)
+                .setParameter("age", age)
+                .setFirstResult(offset)
+                .setMaxResults(limit)
+                .getResultList();
+    }
+
+    public long totalCount(int age) {
+        return em.createQuery("select count(m) from Member m where m.age = :age", Long.class)
+                .setParameter("age", age)
+                .getSingleResult();
+    }
 }

spring-data-jpa/src/test/java/com/example/springdatajpa/repository/MemberJpaRepositoryTest.java

@@ -74,7 +74,7 @@ class MemberJpaRepositoryTest {
     }
 
     @Test
-    public void testNamedQuery() {
+    void testNamedQuery() {
         Member m1 = new Member("aaa", 10);
         Member m2 = new Member("bbb", 20);
         memberJpaRepository.save(m1);
@@ -84,4 +84,26 @@ class MemberJpaRepositoryTest {
 
         assertEquals(m1, result.get(0));
     }
+
+    @Test
+    void paging() {
+        // given
+        memberJpaRepository.save(new Member("member1", 10));
+        memberJpaRepository.save(new Member("member2", 10));
+        memberJpaRepository.save(new Member("member3", 10));
+        memberJpaRepository.save(new Member("member4", 10));
+        memberJpaRepository.save(new Member("member5", 10));
+
+        int age = 10;
+        int offset = 0;
+        int limit = 3;
+
+        // when
+        List<Member> members = memberJpaRepository.findByPage(age, offset, limit);
+        long totalCount = memberJpaRepository.totalCount(age);
+
+        // then
+        assertEquals(3, members.size());
+        assertEquals(5, totalCount);
+    }
 }