add spring jpa specifications test

spring-jpa/src/main/java/org/baeldung/config/PersistenceJPAConfig.java

@@ -12,6 +12,7 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.PropertySource;
 import org.springframework.core.env.Environment;
 import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.jdbc.datasource.DriverManagerDataSource;
 import org.springframework.orm.jpa.JpaTransactionManager;
 import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
@@ -25,6 +26,7 @@ import com.google.common.base.Preconditions;
 @EnableTransactionManagement
 @PropertySource({ "classpath:persistence-mysql.properties" })
 @ComponentScan({ "org.baeldung.persistence" })
+@EnableJpaRepositories(basePackages = "org.baeldung.persistence.dao")
 public class PersistenceJPAConfig {
 
     @Autowired

spring-jpa/src/main/java/org/baeldung/persistence/dao/UserRepository.java

@@ -0,0 +1,9 @@
+package org.baeldung.persistence.dao;
+
+import org.baeldung.persistence.model.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
+
+public interface UserRepository extends JpaRepository<User, Long>, JpaSpecificationExecutor<User> {
+
+}

spring-jpa/src/main/java/org/baeldung/persistence/dao/UserSpecifications.java

@@ -0,0 +1,45 @@
+package org.baeldung.persistence.dao;
+
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Predicate;
+import javax.persistence.criteria.Root;
+
+import org.baeldung.persistence.model.User;
+import org.baeldung.persistence.model.User_;
+import org.springframework.data.jpa.domain.Specification;
+
+public class UserSpecifications {
+    public static Specification<User> firstNameIsLike(final String term) {
+
+        return new Specification<User>() {
+            @Override
+            public Predicate toPredicate(final Root<User> root, final CriteriaQuery<?> query, final CriteriaBuilder cb) {
+                return cb.like(root.get(User_.firstName), "%"+term+"%");
+            }
+
+        };
+    }
+
+    public static Specification<User> lastNameIsLike(final String term) {
+
+        return new Specification<User>() {
+            @Override
+            public Predicate toPredicate(final Root<User> root, final CriteriaQuery<?> query, final CriteriaBuilder cb) {
+                return cb.like(root.get(User_.lastName), "%" + term + "%");
+            }
+
+        };
+    }
+
+    public static Specification<User> ageIsGreaterThan(final int minAge) {
+
+        return new Specification<User>() {
+            @Override
+            public Predicate toPredicate(final Root<User> root, final CriteriaQuery<?> query, final CriteriaBuilder cb) {
+                return cb.greaterThanOrEqualTo(root.get(User_.age), minAge);
+            }
+
+        };
+    }
+}

spring-jpa/src/main/java/org/baeldung/persistence/model/User_.java

@@ -0,0 +1,11 @@
+package org.baeldung.persistence.model;
+
+import javax.persistence.metamodel.SingularAttribute;
+import javax.persistence.metamodel.StaticMetamodel;
+
+@StaticMetamodel(User.class)
+public class User_ {
+    public static volatile SingularAttribute<User, String> firstName;
+    public static volatile SingularAttribute<User, String> lastName;
+    public static volatile SingularAttribute<User, Integer> age;
+}

spring-jpa/src/test/java/org/baeldung/persistence/query/JPACriteriaQueryTest.java

@@ -26,25 +26,25 @@ public class JPACriteriaQueryTest {
     @Autowired
     private UserService userService;
 
-    private User user_john;
+    private User userJohn;
 
-    private User user_tom;
+    private User userTom;
 
     @Before
     public void init() {
-        user_john = new User();
+        userJohn = new User();
-        user_john.setFirstName("John");
+        userJohn.setFirstName("John");
-        user_john.setLastName("Doe");
+        userJohn.setLastName("Doe");
-        user_john.setEmail("john@doe.com");
+        userJohn.setEmail("john@doe.com");
-        user_john.setAge(22);
+        userJohn.setAge(22);
-        userService.saveUser(user_john);
+        userService.saveUser(userJohn);
 
-        user_tom = new User();
+        userTom = new User();
-        user_tom.setFirstName("Tom");
+        userTom.setFirstName("Tom");
-        user_tom.setLastName("Doe");
+        userTom.setLastName("Doe");
-        user_tom.setEmail("tom@doe.com");
+        userTom.setEmail("tom@doe.com");
-        user_tom.setAge(26);
+        userTom.setAge(26);
-        userService.saveUser(user_tom);
+        userService.saveUser(userTom);
     }
 
     @Test
@@ -52,7 +52,7 @@ public class JPACriteriaQueryTest {
         final List<User> result = userService.searchUser("John", "Doe", 0);
 
         assertEquals(1, result.size());
-        assertEquals(user_john.getEmail(), result.get(0).getEmail());
+        assertEquals(userJohn.getEmail(), result.get(0).getEmail());
     }
 
     @Test
@@ -66,7 +66,7 @@ public class JPACriteriaQueryTest {
         final List<User> result = userService.searchUser("", "doe", 25);
 
         assertEquals(1, result.size());
-        assertEquals(user_tom.getEmail(), result.get(0).getEmail());
+        assertEquals(userTom.getEmail(), result.get(0).getEmail());
     }
 
     @Test
@@ -76,10 +76,10 @@ public class JPACriteriaQueryTest {
     }
 
     @Test
-    public void givenPartialFirstAndLast_whenGettingListOfUsers_thenCorrect() {
+    public void givenPartialFirst_whenGettingListOfUsers_thenCorrect() {
         final List<User> result = userService.searchUser("jo", "", 0);
 
         assertEquals(1, result.size());
-        assertEquals(user_john.getEmail(), result.get(0).getEmail());
+        assertEquals(userJohn.getEmail(), result.get(0).getEmail());
     }
 }

spring-jpa/src/test/java/org/baeldung/persistence/query/JPASpecificationsTest.java

@@ -0,0 +1,89 @@
+package org.baeldung.persistence.query;
+
+import static org.baeldung.persistence.dao.UserSpecifications.ageIsGreaterThan;
+import static org.baeldung.persistence.dao.UserSpecifications.firstNameIsLike;
+import static org.baeldung.persistence.dao.UserSpecifications.lastNameIsLike;
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.baeldung.config.PersistenceJPAConfig;
+import org.baeldung.persistence.dao.UserRepository;
+import org.baeldung.persistence.model.User;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.jpa.domain.Specifications;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+import org.springframework.test.context.transaction.TransactionConfiguration;
+import org.springframework.transaction.annotation.Transactional;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { PersistenceJPAConfig.class }, loader = AnnotationConfigContextLoader.class)
+@Transactional
+@TransactionConfiguration
+public class JPASpecificationsTest {
+
+    @Autowired
+    private UserRepository repository;
+
+    private User userJohn;
+
+    private User userTom;
+
+    @Before
+    public void init() {
+        userJohn = new User();
+        userJohn.setFirstName("John");
+        userJohn.setLastName("Doe");
+        userJohn.setEmail("john@doe.com");
+        userJohn.setAge(22);
+        repository.save(userJohn);
+
+        userTom = new User();
+        userTom.setFirstName("Tom");
+        userTom.setLastName("Doe");
+        userTom.setEmail("tom@doe.com");
+        userTom.setAge(26);
+        repository.save(userTom);
+    }
+
+    @Test
+    public void givenLast_whenGettingListOfUsers_thenCorrect() {
+        final List<User> result = repository.findAll(lastNameIsLike("doe"));
+        assertEquals(2, result.size());
+    }
+
+    @Test
+    public void givenFirstAndLastName_whenGettingListOfUsers_thenCorrect() {
+        final List<User> result = repository.findAll(Specifications.where(lastNameIsLike("doe")).and(firstNameIsLike("john")));
+
+        assertEquals(1, result.size());
+        assertEquals(userJohn.getEmail(), result.get(0).getEmail());
+    }
+
+    @Test
+    public void givenLastAndAge_whenGettingListOfUsers_thenCorrect() {
+        final List<User> result = repository.findAll(Specifications.where(lastNameIsLike("doe")).and(ageIsGreaterThan(25)));
+
+        assertEquals(1, result.size());
+        assertEquals(userTom.getEmail(), result.get(0).getEmail());
+    }
+
+    @Test
+    public void givenWrongFirstAndLast_whenGettingListOfUsers_thenCorrect() {
+        final List<User> result = repository.findAll(Specifications.where(lastNameIsLike("Adam")).and(firstNameIsLike("Fox")));
+        assertEquals(0, result.size());
+    }
+
+    @Test
+    public void givenPartialFirst_whenGettingListOfUsers_thenCorrect() {
+        final List<User> result = repository.findAll(firstNameIsLike("jo"));
+
+        assertEquals(1, result.size());
+        assertEquals(userJohn.getEmail(), result.get(0).getEmail());
+    }
+}