Added sample for QueryDsl integration.

Author: odrotbohm

spring-data-jpa-showcase/demo.txt

@@ -34,14 +34,21 @@
 - implementation got obsolete
 - switch to after package
 
+7. Querydsl / Specifications
+----------------------------
+- Introduce Querydsl
+- Show Maven setup
+- Show predicates
+- Integrate test case
+
 7. Custom implementation
 ------------------------
 - copy interface and implementation (hint to visibility)
 - adapt AccountRepository
 - copy test case
 - explain implementation class lookup
 
-8. JDBC implementation
+8. JDBC implementation (optional)
 -----------------------
 - copy implementation -> configuration necessary
 - copy XML

spring-data-jpa-showcase/pom.xml

@@ -13,6 +13,10 @@
 
     <name>Spring Data JPA showcase</name>
     <description>Sample project showing how Spring Data JPA eases implementing repositories over a plain JPA/Spring approach</description>
+    
+    <properties>
+    	<querydsl.version>2.1.1</querydsl.version>
+    </properties>
 
     <build>
 
@@ -71,5 +75,59 @@
 			</plugin>
         </plugins>
     </build>
+    
+    <profiles>
+    	<profile>
+    		<id>querydsl</id>
+    		<activation>
+    			<activeByDefault>true</activeByDefault>
+    		</activation>
+    		<dependencies>
+		    	<!-- QueryDsl -->
+				<dependency>
+					<groupId>com.mysema.querydsl</groupId>
+					<artifactId>querydsl-apt</artifactId>
+					<version>${querydsl.version}</version>
+					<scope>provided</scope>
+				</dependency>
+				
+				<dependency>
+					<groupId>com.mysema.querydsl</groupId>
+					<artifactId>querydsl-jpa</artifactId>
+					<version>${querydsl.version}</version>
+				</dependency>
+		    </dependencies>
+		    
+		    <repositories>
+		    	<repository>
+					<id>querydsl</id>
+					<name>QueryDsl</name>
+					<url>http://source.mysema.com/maven2/releases</url>
+				</repository>
+		    </repositories>
+		    
+		    <build>
+		    	<plugins>
+		    		<plugin>
+						<groupId>com.mysema.maven</groupId>
+						<artifactId>maven-apt-plugin</artifactId>
+						<version>1.0</version>
+						<executions>
+							<execution>
+								<phase>generate-sources</phase>
+								<goals>
+									<goal>process</goal>
+								</goals>
+								<configuration>
+									<outputDirectory>target/generated-sources/queries</outputDirectory>
+									<processor>com.mysema.query.apt.jpa.JPAAnnotationProcessor</processor>
+								</configuration>
+							</execution>
+						</executions>
+					</plugin>
+		    	</plugins>
+		    </build>
+    	</profile>
+    </profiles>
 
 </project>

spring-data-jpa-showcase/src/main/java/org/springframework/data/jpa/showcase/after/AccountRepository.java

@@ -13,11 +13,11 @@
  */
 public interface AccountRepository extends CrudRepository<Account, Long> {
 
-    /**
-     * Returns all accounts belonging to the given {@link Customer}.
-     * 
-     * @param customer
-     * @return
-     */
-    List<Account> findByCustomer(Customer customer);
+	/**
+	 * Returns all accounts belonging to the given {@link Customer}.
+	 * 
+	 * @param customer
+	 * @return
+	 */
+	List<Account> findByCustomer(Customer customer);
 }

spring-data-jpa-showcase/src/snippets/java/org/springframework/data/jpa/showcase/snippets/AccountPredicates.java

@@ -0,0 +1,25 @@
+package org.springframework.data.jpa.showcase.snippets;
+
+import org.joda.time.LocalDate;
+import org.springframework.data.jpa.showcase.core.Account;
+import org.springframework.data.jpa.showcase.core.QAccount;
+
+import com.mysema.query.types.expr.BooleanExpression;
+
+/**
+ * Predicates for {@link Account}s.
+ * 
+ * @author Oliver Gierke
+ */
+public class AccountPredicates {
+
+	private static QAccount $ = QAccount.account;
+
+	public static BooleanExpression isExpired() {
+		return expiresBefore(new LocalDate());
+	}
+
+	public static BooleanExpression expiresBefore(LocalDate date) {
+		return $.expiryDate.before(date.toDateMidnight().toDate());
+	}
+}

spring-data-jpa-showcase/src/snippets/java/org/springframework/data/jpa/showcase/snippets/AccountRepository.java

@@ -4,21 +4,22 @@
 
 import org.springframework.data.jpa.showcase.core.Account;
 import org.springframework.data.jpa.showcase.core.Customer;
+import org.springframework.data.querydsl.QueryDslPredicateExecutor;
 import org.springframework.data.repository.CrudRepository;
 
-
 /**
  * Repository to manage {@link Account} instances.
  * 
  * @author Oliver Gierke
  */
-public interface AccountRepository extends CrudRepository<Account, Long>, AccountRepositoryCustom {
+public interface AccountRepository extends CrudRepository<Account, Long>, AccountRepositoryCustom,
+		QueryDslPredicateExecutor<Account> {
 
-    /**
-     * Returns all accounts belonging to the given {@link Customer}.
-     * 
-     * @param customer
-     * @return
-     */
-    List<Account> findByCustomer(Customer customer);
+	/**
+	 * Returns all accounts belonging to the given {@link Customer}.
+	 * 
+	 * @param customer
+	 * @return
+	 */
+	List<Account> findByCustomer(Customer customer);
 }

spring-data-jpa-showcase/src/snippets/java/org/springframework/data/jpa/showcase/snippets/CustomerSpecifications.java

@@ -13,38 +13,33 @@
 import org.springframework.data.jpa.showcase.core.Account;
 import org.springframework.data.jpa.showcase.core.Customer;
 
-
 /**
  * Collection of {@link Specification} implementations.
  * 
  * @author Oliver Gierke
  */
 public class CustomerSpecifications {
 
-    /**
-     * All customers with an {@link Account} expiring before the given date.
-     * 
-     * @param date
-     * @return
-     */
-    public static Specification<Customer> accountExpiresBefore(
-            final LocalDate date) {
-
-        return new Specification<Customer>() {
-
-            @Override
-            public Predicate toPredicate(Root<Customer> root,
-                    CriteriaQuery<?> query, CriteriaBuilder cb) {
-
-                Root<Account> accounts = query.from(Account.class);
-                Path<Date> expiryDate = accounts.<Date> get("expiryDate");
-                Predicate customerIsAccountOwner =
-                        cb.equal(accounts.<Customer> get("customer"), root);
-                Predicate accountExpiryDateBefore =
-                        cb.lessThan(expiryDate, date.toDateMidnight().toDate());
-
-                return cb.and(customerIsAccountOwner, accountExpiryDateBefore);
-            }
-        };
-    }
+	/**
+	 * All customers with an {@link Account} expiring before the given date.
+	 * 
+	 * @param date
+	 * @return
+	 */
+	public static Specification<Customer> accountExpiresBefore(final LocalDate date) {
+
+		return new Specification<Customer>() {
+
+			@Override
+			public Predicate toPredicate(Root<Customer> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
+
+				Root<Account> accounts = query.from(Account.class);
+				Path<Date> expiryDate = accounts.<Date> get("expiryDate");
+				Predicate customerIsAccountOwner = cb.equal(accounts.<Customer> get("customer"), root);
+				Predicate accountExpiryDateBefore = cb.lessThan(expiryDate, date.toDateMidnight().toDate());
+
+				return cb.and(customerIsAccountOwner, accountExpiryDateBefore);
+			}
+		};
+	}
 }

spring-data-jpa-showcase/src/test-snippets/java/org/springframework/data/jpa/showcase/snippets/test/AccountRepositoryIntegrationTest.java

@@ -1,23 +1,34 @@
 package org.springframework.data.jpa.showcase.snippets.test;
 
-import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
+import static org.springframework.data.jpa.showcase.snippets.AccountPredicates.*;
 
 import org.joda.time.LocalDate;
+import org.springframework.data.jpa.showcase.core.Account;
 import org.springframework.data.jpa.showcase.snippets.AccountRepository;
 
-
 /**
  * @author Oliver Gierke
  */
 public abstract class AccountRepositoryIntegrationTest {
 
-    private AccountRepository accountRepository;
+	private AccountRepository accountRepository;
+
+	public void removesExpiredAccountsCorrectly() throws Exception {
+
+		accountRepository.removedExpiredAccounts(new LocalDate(2011, 1, 1));
+		assertThat(accountRepository.count(), is(1L));
+	}
+
+	public void findsExpiredAccounts() {
 
+		Account expired = accountRepository.findOne(1L);
+		Account valid = accountRepository.findOne(2L);
 
-    public void removesExpiredAccountsCorrectly() throws Exception {
+		Iterable<Account> findAll = accountRepository.findAll(expiresBefore(new LocalDate(2011, 3, 1)));
 
-        accountRepository.removedExpiredAccounts(new LocalDate(2011, 1, 1));
-        assertThat(accountRepository.count(), is(1L));
-    }
+		assertThat(findAll, hasItem(expired));
+		assertThat(findAll, not(hasItem(valid)));
+	}
 }

spring-data-jpa-showcase/src/test-snippets/java/org/springframework/data/jpa/showcase/snippets/test/CustomerRepositoryIntegrationTest.java

@@ -12,26 +12,23 @@
 import org.springframework.data.jpa.showcase.after.CustomerRepository;
 import org.springframework.data.jpa.showcase.core.Customer;
 
-
 /**
  * Snippets to show the usage of {@link Specification}s.
  * 
  * @author Oliver Gierke
  */
 public class CustomerRepositoryIntegrationTest {
 
-    CustomerRepository repository;
-
+	CustomerRepository repository;
 
-    public void findsCustomersBySpecification() throws Exception {
+	public void findsCustomersBySpecification() throws Exception {
 
-        Customer dave = repository.findOne(1L);
+		Customer dave = repository.findOne(1L);
 
-        LocalDate expiryLimit = new LocalDate(2011, 3, 1);
-        List<Customer> result =
-                repository.findAll(where(accountExpiresBefore(expiryLimit)));
+		LocalDate expiryLimit = new LocalDate(2011, 3, 1);
+		List<Customer> result = repository.findAll(where(accountExpiresBefore(expiryLimit)));
 
-        assertThat(result.size(), is(1));
-        assertThat(result, hasItems(dave));
-    }
+		assertThat(result.size(), is(1));
+		assertThat(result, hasItems(dave));
+	}
 }

spring-data-jpa-showcase/src/test/java/org/springframework/data/jpa/showcase/after/AccountRepositoryIntegrationTest.java

@@ -1,6 +1,6 @@
 package org.springframework.data.jpa.showcase.after;
 
-import static org.hamcrest.CoreMatchers.*;
+import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
 import java.util.List;
@@ -12,27 +12,25 @@
 import org.springframework.data.jpa.showcase.core.Customer;
 import org.springframework.test.context.ContextConfiguration;
 
-
 /**
  * @author Oliver Gierke
  */
 @ContextConfiguration("classpath:application-context-after.xml")
 public class AccountRepositoryIntegrationTest extends AbstractShowcaseTest {
 
-    @Autowired
-    AccountRepository accountRepository;
-
-    @Autowired
-    CustomerRepository customerRepository;
+	@Autowired
+	AccountRepository accountRepository;
 
+	@Autowired
+	CustomerRepository customerRepository;
 
-    @Test
-    public void findsCustomersAccounts() throws Exception {
+	@Test
+	public void findsCustomersAccounts() {
 
-        Customer customer = customerRepository.findOne(1L);
-        List<Account> accounts = accountRepository.findByCustomer(customer);
+		Customer customer = customerRepository.findOne(1L);
+		List<Account> accounts = accountRepository.findByCustomer(customer);
 
-        assertFalse(accounts.isEmpty());
-        assertThat(accounts.get(0).getCustomer(), is(customer));
-    }
+		assertFalse(accounts.isEmpty());
+		assertThat(accounts.get(0).getCustomer(), is(customer));
+	}
 }

spring-data-jpa-showcase/src/test/java/org/springframework/data/jpa/showcase/after/CustomerRepositoryIntegrationTest.java

@@ -2,7 +2,12 @@
 
 import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
+import static org.springframework.data.jpa.domain.Specifications.*;
+import static org.springframework.data.jpa.showcase.snippets.CustomerSpecifications.*;
 
+import java.util.List;
+
+import org.joda.time.LocalDate;
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
@@ -46,4 +51,16 @@ public void findsCustomerById() throws Exception {
 		assertThat(customer.getFirstname(), is("Carter"));
 		assertThat(customer.getLastname(), is("Beauford"));
 	}
+
+	@Test
+	public void findsCustomersBySpecification() throws Exception {
+
+		Customer dave = repository.findOne(1L);
+
+		LocalDate expiryLimit = new LocalDate(2011, 3, 1);
+		List<Customer> result = repository.findAll(where(accountExpiresBefore(expiryLimit)));
+
+		assertThat(result.size(), is(1));
+		assertThat(result, hasItems(dave));
+	}
 }

spring-data-jpa-showcase/template.mf

@@ -9,8 +9,9 @@ Import-Package:
  org.hsqldb;version="[1.8.0,1.9.0)"
 Export-Template: 
  org.springframework.data.jpa.sample.*;version="${project.version}"
-Import-Template: 
- javax.persistence.*;version="${jpa.version:[=.=.=,+1.0.0)}", 
+Import-Template:
+ com.mysema.query.*;version="${querydsl.version:[2.1.1,+1.0.0)}",
+ javax.persistence.*;version="${jpa.version:[=.=.=,+1.0.0)}",
  org.springframework.*;version="${spring.version:[=.=.=.=,+1.0.0)}",
  org.springframework.data.*;version="${project.version:[=.=.=.=,+1.0.0)}",
  org.joda.time.*;version="${jodatime.version:[=.=.=,+1.0.0]}"