JAVA-8363: Move etag code to spring-boot-mvc-3

spring-boot-modules/spring-boot-mvc-3/pom.xml

@@ -27,6 +27,14 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-thymeleaf</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+        </dependency>
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>

spring-boot-modules/spring-boot-mvc-3/src/main/java/com/baeldung/etag/Foo.java

@@ -0,0 +1,94 @@
+package com.baeldung.etag;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Version;
+import java.io.Serializable;
+
+@Entity
+public class Foo implements Serializable {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+
+    @Column(nullable = false)
+    private String name;
+    
+    @Version
+    private long version;
+
+    public Foo() {
+        super();
+    }
+
+    public Foo(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    // API
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public long getVersion() {
+        return version;
+    }
+
+    public void setVersion(long version) {
+        this.version = version;
+    }
+    
+    //
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        final Foo other = (Foo) obj;
+        if (name == null) {
+            if (other.name != null)
+                return false;
+        } else if (!name.equals(other.name))
+            return false;
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Foo [name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

spring-boot-modules/spring-boot-mvc-3/src/main/java/com/baeldung/etag/FooController.java

@@ -0,0 +1,58 @@
+package com.baeldung.etag;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+import javax.servlet.http.HttpServletResponse;
+
+@RestController
+@RequestMapping(value = "/foos")
+public class FooController {
+
+	@Autowired
+	private FooDao fooDao;
+
+	@GetMapping(value = "/{id}")
+	public Foo findById(@PathVariable("id") final Long id, final HttpServletResponse response) {
+		return fooDao.findById(id).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+	}
+
+	// Note: the global filter overrides the ETag value we set here. We can still
+	// analyze its behaviour in the Integration Test.
+	@GetMapping(value = "/{id}/custom-etag")
+	public ResponseEntity<Foo> findByIdWithCustomEtag(@PathVariable("id") final Long id,
+			final HttpServletResponse response) {
+		final Foo foo = fooDao.findById(id).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		return ResponseEntity.ok().eTag(Long.toString(foo.getVersion())).body(foo);
+	}
+
+	@PostMapping
+	@ResponseStatus(HttpStatus.CREATED)
+	public Foo create(@RequestBody final Foo resource, final HttpServletResponse response) {
+		return fooDao.save(resource);
+	}
+
+	@PutMapping(value = "/{id}")
+	@ResponseStatus(HttpStatus.OK)
+	public void update(@PathVariable("id") final Long id, @RequestBody final Foo resource) {
+		fooDao.save(resource);
+	}
+
+	@DeleteMapping(value = "/{id}")
+	@ResponseStatus(HttpStatus.OK)
+	public void delete(@PathVariable("id") final Long id) {
+		fooDao.deleteById(id);
+	}
+
+}

spring-boot-modules/spring-boot-mvc-3/src/main/java/com/baeldung/etag/FooDao.java

@@ -0,0 +1,8 @@
+package com.baeldung.etag;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface FooDao extends CrudRepository<Foo, Long>{
+}

spring-boot-modules/spring-boot-mvc-3/src/main/java/com/baeldung/etag/SpringBootEtagApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.etag;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringBootEtagApplication {
+
+	public static void main(String[] args) {
+        SpringApplication.run(SpringBootEtagApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-mvc-3/src/main/java/com/baeldung/etag/WebConfig.java

@@ -0,0 +1,28 @@
+package com.baeldung.etag;
+
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.filter.ShallowEtagHeaderFilter;
+
+@Configuration
+public class WebConfig {
+
+    // Etags
+
+    // If we're not using Spring Boot we can make use of
+    // AbstractAnnotationConfigDispatcherServletInitializer#getServletFilters
+    @Bean
+    public FilterRegistrationBean<ShallowEtagHeaderFilter> shallowEtagHeaderFilter() {
+        FilterRegistrationBean<ShallowEtagHeaderFilter> filterRegistrationBean = new FilterRegistrationBean<>( new ShallowEtagHeaderFilter());
+        filterRegistrationBean.addUrlPatterns("/foos/*");
+        filterRegistrationBean.setName("etagFilter");
+        return filterRegistrationBean;
+    }
+    
+    // We can also just declare the filter directly
+    // @Bean
+    // public ShallowEtagHeaderFilter shallowEtagHeaderFilter() {
+    // return new ShallowEtagHeaderFilter();
+    // }
+}

spring-boot-modules/spring-boot-mvc-3/src/main/resources/WEB-INF/web.xml

@@ -0,0 +1,18 @@
+<!--  NOTE: web.xml is not used in Spring Boot. This is just for guidance, showing how an Etag Filter would be implemented using XML-based configs  -->
+
+<!-- <?xml version="1.0" encoding="UTF-8"?> -->
+<!-- <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" -->
+<!--     xsi:schemaLocation=" -->
+<!--       http://java.sun.com/xml/ns/javaee -->
+<!--       http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0" -->
+<!-- > -->
+
+<!--     <filter> -->
+<!--         <filter-name>etagFilter</filter-name> -->
+<!--         <filter-class>org.springframework.web.filter.ShallowEtagHeaderFilter</filter-class> -->
+<!--     </filter> -->
+<!--     <filter-mapping> -->
+<!--         <filter-name>etagFilter</filter-name> -->
+<!--         <url-pattern>/*</url-pattern> -->
+<!--     </filter-mapping> -->
+<!-- </web-app> -->

spring-boot-modules/spring-boot-mvc-3/src/test/java/com/baeldung/etag/EtagIntegrationTest.java

@@ -0,0 +1,121 @@
+package com.baeldung.etag;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.restassured.RestAssured;
+import io.restassured.http.ContentType;
+import io.restassured.response.Response;
+import org.assertj.core.util.Preconditions;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ComponentScan(basePackageClasses = WebConfig.class)
+@EnableAutoConfiguration
+public class EtagIntegrationTest {
+
+	@LocalServerPort
+	private int port;
+
+	@Test
+	public void givenResourceExists_whenRetrievingResource_thenEtagIsAlsoReturned() {
+		// Given
+		final String uriOfResource = createAsUri();
+
+		// When
+		final Response findOneResponse = RestAssured.given().header("Accept", "application/json").get(uriOfResource);
+
+		// Then
+		assertNotNull(findOneResponse.getHeader(HttpHeaders.ETAG));
+	}
+
+	@Test
+	public void givenResourceWasRetrieved_whenRetrievingAgainWithEtag_thenNotModifiedReturned() {
+		// Given
+		final String uriOfResource = createAsUri();
+		final Response findOneResponse = RestAssured.given().header("Accept", "application/json").get(uriOfResource);
+		final String etagValue = findOneResponse.getHeader(HttpHeaders.ETAG);
+
+		// When
+		final Response secondFindOneResponse = RestAssured.given().header("Accept", "application/json")
+				.headers("If-None-Match", etagValue).get(uriOfResource);
+
+		// Then
+		assertTrue(secondFindOneResponse.getStatusCode() == 304);
+	}
+
+	@Test
+	public void givenResourceWasRetrievedThenModified_whenRetrievingAgainWithEtag_thenResourceIsReturned() {
+		// Given
+		final String uriOfResource = createAsUri();
+		final Response firstFindOneResponse = RestAssured.given().header("Accept", "application/json")
+				.get(uriOfResource);
+		final String etagValue = firstFindOneResponse.getHeader(HttpHeaders.ETAG);
+		final long createdId = firstFindOneResponse.jsonPath().getLong("id");
+
+		Foo updatedFoo = new Foo("updated value");
+		updatedFoo.setId(createdId);
+		Response updatedResponse = RestAssured.given().contentType(ContentType.JSON).body(updatedFoo)
+				.put(uriOfResource);
+		assertThat(updatedResponse.getStatusCode() == 200);
+
+		// When
+		final Response secondFindOneResponse = RestAssured.given().header("Accept", "application/json")
+				.headers("If-None-Match", etagValue).get(uriOfResource);
+
+		// Then
+		assertTrue(secondFindOneResponse.getStatusCode() == 200);
+	}
+
+	@Test
+	@Ignore("Not Yet Implemented By Spring - https://jira.springsource.org/browse/SPR-10164")
+	public void givenResourceExists_whenRetrievedWithIfMatchIncorrectEtag_then412IsReceived() {
+		// Given
+		final String uriOfResource = createAsUri();
+
+		// When
+		final Response findOneResponse = RestAssured.given().header("Accept", "application/json")
+				.headers("If-Match", randomAlphabetic(8)).get(uriOfResource);
+
+		// Then
+		assertTrue(findOneResponse.getStatusCode() == 412);
+	}
+
+	private final String createAsUri() {
+		final Response response = createAsResponse(new Foo(randomAlphabetic(6)));
+		Preconditions.checkState(response.getStatusCode() == 201, "create operation: " + response.getStatusCode());
+
+		return getURL() + "/" + response.getBody().as(Foo.class).getId();
+	}
+
+	private Response createAsResponse(final Foo resource) {
+		String resourceAsString;
+		try {
+			resourceAsString = new ObjectMapper().writeValueAsString(resource);
+		} catch (JsonProcessingException e) {
+			throw new AssertionError("Error during serialization");
+		}
+		return RestAssured.given().contentType(MediaType.APPLICATION_JSON.toString()).body(resourceAsString)
+				.post(getURL());
+	}
+
+	private String getURL() {
+		return "http://localhost:" + port + "/foos";
+	}
+
+}