Configure RestTemplate with required HttpMessageConverters.

VaultClients.createRestTemplate() creates a RestTemplate that is configured with ByteArray, String and Jackson 2 message converters to avoid additional message converters to be registered, if they were on available on the classpath.

Fixes gh-47.

spring-vault-core/src/main/java/org/springframework/vault/client/VaultClients.java

@@ -17,6 +17,8 @@ package org.springframework.vault.client;
 
 import java.io.IOException;
 import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 
 import org.springframework.http.HttpRequest;
@@ -24,6 +26,10 @@ import org.springframework.http.client.ClientHttpRequestExecution;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.http.converter.ByteArrayHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.converter.StringHttpMessageConverter;
+import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.util.DefaultUriTemplateHandler;
 
@@ -46,18 +52,50 @@ public class VaultClients {
 	 * request body size that is required to send a
 	 * {@link org.springframework.http.HttpHeaders#CONTENT_LENGTH} request header.
 	 * Otherwise, Vault will deny body processing.
+	 * <p>
+	 * Requires Jackson 2 for Object-to-JSON mapping.
 	 *
 	 * @param endpoint must not be {@literal null}.
 	 * @param requestFactory must not be {@literal null}.
 	 * @return the {@link RestTemplate}.
 	 * @see org.springframework.http.client.Netty4ClientHttpRequestFactory
+	 * @see MappingJackson2HttpMessageConverter
 	 */
 	public static RestTemplate createRestTemplate(VaultEndpoint endpoint,
 			ClientHttpRequestFactory requestFactory) {
 
-		RestTemplate restTemplate = new RestTemplate(requestFactory);
+		RestTemplate restTemplate = createRestTemplate();
 
+		restTemplate.setRequestFactory(requestFactory);
 		restTemplate.setUriTemplateHandler(createUriTemplateHandler(endpoint));
+
+		return restTemplate;
+	}
+
+	/**
+	 * Create a {@link RestTemplate} for Vault interaction. {@link RestTemplate} is
+	 * configured with a {@link ClientHttpRequestInterceptor} to enforce serialization to
+	 * a byte array prior continuing the request. Eager serialization leads to a known
+	 * request body size that is required to send a
+	 * {@link org.springframework.http.HttpHeaders#CONTENT_LENGTH} request header.
+	 * Otherwise, Vault will deny body processing.
+	 * <p>
+	 * Requires Jackson 2 for Object-to-JSON mapping.
+	 *
+	 * @return the {@link RestTemplate}.
+	 * @see org.springframework.http.client.Netty4ClientHttpRequestFactory
+	 * @see MappingJackson2HttpMessageConverter
+	 */
+	public static RestTemplate createRestTemplate() {
+
+		List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>(
+				3);
+		messageConverters.add(new ByteArrayHttpMessageConverter());
+		messageConverters.add(new StringHttpMessageConverter());
+		messageConverters.add(new MappingJackson2HttpMessageConverter());
+
+		RestTemplate restTemplate = new RestTemplate(messageConverters);
+
 		restTemplate.getInterceptors().add(new ClientHttpRequestInterceptor() {
 
 			@Override

spring-vault-core/src/test/java/org/springframework/vault/authentication/AppIdAuthenticationUnitTests.java

@@ -22,6 +22,7 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.client.MockRestServiceServer;
 import org.springframework.vault.VaultException;
+import org.springframework.vault.client.VaultClients;
 import org.springframework.vault.client.VaultClients.PrefixAwareUriTemplateHandler;
 import org.springframework.vault.support.VaultToken;
 import org.springframework.web.client.RestTemplate;
@@ -46,7 +47,7 @@ public class AppIdAuthenticationUnitTests {
 	@Before
 	public void before() throws Exception {
 
-		RestTemplate restTemplate = new RestTemplate();
+		RestTemplate restTemplate = VaultClients.createRestTemplate();
 		restTemplate.setUriTemplateHandler(new PrefixAwareUriTemplateHandler());
 		this.mockRest = MockRestServiceServer.createServer(restTemplate);
 		this.restTemplate = restTemplate;

spring-vault-core/src/test/java/org/springframework/vault/authentication/AppRoleAuthenticationUnitTests.java

@@ -22,6 +22,7 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.client.MockRestServiceServer;
 import org.springframework.vault.VaultException;
+import org.springframework.vault.client.VaultClients;
 import org.springframework.vault.client.VaultClients.PrefixAwareUriTemplateHandler;
 import org.springframework.vault.support.VaultToken;
 import org.springframework.web.client.RestTemplate;
@@ -46,7 +47,7 @@ public class AppRoleAuthenticationUnitTests {
 	@Before
 	public void before() throws Exception {
 
-		RestTemplate restTemplate = new RestTemplate();
+		RestTemplate restTemplate = VaultClients.createRestTemplate();
 		restTemplate.setUriTemplateHandler(new PrefixAwareUriTemplateHandler());
 
 		this.mockRest = MockRestServiceServer.createServer(restTemplate);

spring-vault-core/src/test/java/org/springframework/vault/authentication/AwsEc2AuthenticationUnitTests.java

@@ -25,6 +25,7 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.client.MockRestServiceServer;
 import org.springframework.vault.VaultException;
+import org.springframework.vault.client.VaultClients;
 import org.springframework.vault.client.VaultClients.PrefixAwareUriTemplateHandler;
 import org.springframework.vault.support.VaultToken;
 import org.springframework.web.client.RestTemplate;
@@ -49,7 +50,7 @@ public class AwsEc2AuthenticationUnitTests {
 	@Before
 	public void before() throws Exception {
 
-		RestTemplate restTemplate = new RestTemplate();
+		RestTemplate restTemplate = VaultClients.createRestTemplate();
 		restTemplate.setUriTemplateHandler(new PrefixAwareUriTemplateHandler());
 
 		this.mockRest = MockRestServiceServer.createServer(restTemplate);

spring-vault-core/src/test/java/org/springframework/vault/authentication/ClientCertificateAuthenticationUnitTests.java

@@ -22,6 +22,7 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.client.MockRestServiceServer;
 import org.springframework.vault.VaultException;
+import org.springframework.vault.client.VaultClients;
 import org.springframework.vault.client.VaultClients.PrefixAwareUriTemplateHandler;
 import org.springframework.vault.support.VaultToken;
 import org.springframework.web.client.RestTemplate;
@@ -45,7 +46,7 @@ public class ClientCertificateAuthenticationUnitTests {
 	@Before
 	public void before() throws Exception {
 
-		RestTemplate restTemplate = new RestTemplate();
+		RestTemplate restTemplate = VaultClients.createRestTemplate();
 		restTemplate.setUriTemplateHandler(new PrefixAwareUriTemplateHandler());
 
 		this.mockRest = MockRestServiceServer.createServer(restTemplate);