Added showcase for JDK 8's Optional support on repository methods.

Abbreviated JPA sample module folder names. Renamed the Java 8 auditing sample module to Java 8 module as it not only contains samples for auditing anymore.

jpa/interceptors/src/main/java/example/springdata/jpa/interceptors/ApplicationConfiguration.java

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+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.interceptors;
+
+import org.springframework.aop.Advisor;
+import org.springframework.aop.aspectj.AspectJExpressionPointcut;
+import org.springframework.aop.interceptor.CustomizableTraceInterceptor;
+import org.springframework.aop.support.DefaultPointcutAdvisor;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.EnableAspectJAutoProxy;
+
+@Configuration
+@EnableAspectJAutoProxy
+@EnableAutoConfiguration
+public class ApplicationConfiguration {
+
+	@Bean
+	public CustomizableTraceInterceptor interceptor() {
+
+		CustomizableTraceInterceptor interceptor = new CustomizableTraceInterceptor();
+		interceptor.setEnterMessage("Entering $[methodName]($[arguments]).");
+		interceptor.setExitMessage("Leaving $[methodName](..) with return value $[returnValue], took $[invocationTime]ms.");
+
+		return interceptor;
+	}
+
+	@Bean
+	public Advisor traceAdvisor() {
+
+		AspectJExpressionPointcut pointcut = new AspectJExpressionPointcut();
+		pointcut.setExpression("execution(public * org.springframework.data.repository.Repository+.*(..))");
+
+		return new DefaultPointcutAdvisor(pointcut, interceptor());
+	}
+}

jpa/interceptors/src/main/java/example/springdata/jpa/interceptors/Customer.java

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+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.interceptors;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class Customer {
+
+	@Id @GeneratedValue Long id;
+
+	String firstname;
+	String lastname;
+
+}

jpa/interceptors/src/main/java/example/springdata/jpa/interceptors/CustomerRepository.java

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+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.interceptors;
+
+import org.springframework.data.repository.CrudRepository;
+
+public interface CustomerRepository extends CrudRepository<Customer, Long> {
+
+}

jpa/interceptors/src/test/java/example/springdata/jpa/interceptors/InterceptorIntegrationTest.java

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+/*
+ * Copyright 2012-2014 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package example.springdata.jpa.interceptors;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = ApplicationConfiguration.class)
+public class InterceptorIntegrationTest {
+
+	@Autowired CustomerRepository repository;
+
+	@Test
+	public void foo() {
+
+		Customer customer = new Customer();
+		customer.firstname = "Dave";
+		customer.lastname = "Matthews";
+
+		repository.save(customer);
+	}
+}

jpa/interceptors/src/test/resources/logback.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+
+	<appender name="console" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d %5p %40.40c:%4L - %m%n</pattern>
+		</encoder>
+	</appender>
+
+	<logger name="org.springframework" level="error" />
+	<logger name="org.springframework.aop.interceptor" level="trace" />
+
+	<root level="error">
+		<appender-ref ref="console" />
+	</root>
+
+</configuration>