Forward Response Content AND Status

src/main/java/edu/wisc/my/restproxy/dao/RestProxyDao.java

@@ -3,6 +3,8 @@
  */
 package edu.wisc.my.restproxy.dao;
 
+import org.springframework.http.ResponseEntity;
+
 import edu.wisc.my.restproxy.ProxyRequestContext;
 
 /**
@@ -13,9 +15,8 @@
 public interface RestProxyDao {
 
   /**
-   * 
    * @param proxyRequestContext
-   * @return the response of the proxied request, serialized to an {@link Object}
+   * @return the {@link ResponseEntity} of the proxied request.
    */
-  public Object proxyRequest(ProxyRequestContext proxyRequestContext);
+  public ResponseEntity<Object> proxyRequest(ProxyRequestContext proxyRequestContext);
 }

src/main/java/edu/wisc/my/restproxy/dao/RestProxyDaoImpl.java

@@ -9,6 +9,7 @@
 import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
@@ -21,23 +22,33 @@
 /**
  * {@link RestProxyDao} implementation backed by a {@link RestTemplate}.
  * 
- * A default instance is provided, but consumers are strongly recommended to configure
- * their own instance and inject.
+ * A default {@link RestTemplate} instance is provided, but consumers are strongly recommended to
+ * configure their own instance and inject. However, this class will always use
+ * {@link RestProxyResponseErrorHandler} because it's the client's responsiblity to deal with
+ * errors.
  * 
  * @author Nicholas Blair
  */
 @Service
-public class RestProxyDaoImpl implements RestProxyDao {
-
+public class RestProxyDaoImpl implements RestProxyDao, InitializingBean {
+  
   @Autowired(required=false)
   private RestTemplate restTemplate = new RestTemplate();
 
+  /* (non-Javadoc)
+   * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
+   */
+  @Override
+  public void afterPropertiesSet() throws Exception {
+    this.restTemplate.setErrorHandler(new RestProxyResponseErrorHandler());
+  };
+
   private static final Logger logger = LoggerFactory.getLogger(RestProxyDaoImpl.class);
   /* (non-Javadoc)
    * @see edu.wisc.my.restproxy.dao.RestProxyDao#proxyRequest(edu.wisc.my.restproxy.ProxyRequestContext)
    */
   @Override
-  public Object proxyRequest(ProxyRequestContext context) {
+  public ResponseEntity<Object> proxyRequest(ProxyRequestContext context) {
     HttpHeaders headers = new HttpHeaders();
     if(StringUtils.isNotBlank(context.getUsername()) && null != context.getPassword()) {
       StringBuffer credsBuffer = new StringBuffer(context.getUsername());
@@ -54,12 +65,10 @@ public Object proxyRequest(ProxyRequestContext context) {
     }
 
     HttpEntity<Object> request = context.getRequestBody() == null ? new HttpEntity<Object>(headers) : new HttpEntity<Object>(context.getRequestBody().getBody(), headers);
-
     ResponseEntity<Object> response = restTemplate.exchange(context.getUri(), 
-        context.getHttpMethod(), request, Object.class, context.getAttributes());
+          context.getHttpMethod(), request, Object.class, context.getAttributes());
     logger.trace("completed request for {}, response= {}", context, response);
-    Object responseBody = response.getBody();
-    return responseBody;
+    return response;
   }
 
 }

src/main/java/edu/wisc/my/restproxy/dao/RestProxyResponseErrorHandler.java

@@ -0,0 +1,43 @@
+/**
+ * 
+ */
+package edu.wisc.my.restproxy.dao;
+
+import java.io.IOException;
+
+import org.springframework.http.client.ClientHttpRequest;
+import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.web.client.ResponseErrorHandler;
+
+/**
+ * {@link ResponseErrorHandler} implementation that does nothing and considers every
+ * {@link ClientHttpRequest} a success.
+ * 
+ * This class does nothing because RestProxy is responsible soley for relaying requests and
+ * responses. We don't care what's in the response, we just forward it on. It's up to the client to deal
+ * with responses, whether they're successes or errors.
+ * 
+ * @author Collin Cudd
+ */
+public class RestProxyResponseErrorHandler implements ResponseErrorHandler {
+
+  /*
+   * (non-Javadoc)
+   * 
+   * @see
+   * org.springframework.web.client.ResponseErrorHandler#handleError(org.springframework.http.client
+   * .ClientHttpResponse)
+   */
+  @Override
+  public void handleError(ClientHttpResponse response) throws IOException {
+    //no-op
+  }
+
+  /* (non-Javadoc)
+   * @see org.springframework.web.client.ResponseErrorHandler#hasError(org.springframework.http.client.ClientHttpResponse)
+   */
+  @Override
+  public boolean hasError(ClientHttpResponse response) throws IOException {
+    return false;
+  }
+}

src/main/java/edu/wisc/my/restproxy/service/RestProxyService.java

@@ -5,6 +5,8 @@
 
 import javax.servlet.http.HttpServletRequest;
 
+import org.springframework.http.ResponseEntity;
+
 import edu.wisc.my.restproxy.ProxyRequestContext;
 
 /**
@@ -19,7 +21,7 @@ public interface RestProxyService {
    * 
    * @param resourceKey
    * @param request
-   * @return the Object returned from the REST API, serialized to an {@link Object} (may return null)
+   * @return the {@link ResponseEntity} returned from the REST API (may return null)
    */
-  public Object proxyRequest(String resourceKey, HttpServletRequest request);
+  public ResponseEntity<Object> proxyRequest(String resourceKey, HttpServletRequest request);
 }

src/main/java/edu/wisc/my/restproxy/service/RestProxyServiceImpl.java

@@ -14,7 +14,7 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.env.Environment;
 import org.springframework.http.HttpMethod;
-import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
 import org.springframework.util.FileCopyUtils;
 import org.springframework.web.servlet.HandlerMapping;
@@ -62,7 +62,7 @@ void setEnv(Environment env) {
    * @see KeyUtils#getProxyHeaders(Environment, String, HttpServletRequest)
    */
   @Override
-  public Object proxyRequest(final String resourceKey, final HttpServletRequest request) {
+  public ResponseEntity<Object> proxyRequest(final String resourceKey, final HttpServletRequest request) {
     final String resourceRoot = env.getProperty(resourceKey + ".uri"); 
     if(StringUtils.isBlank(resourceRoot)) {
       logger.info("unknown resourceKey {}", resourceKey);
@@ -95,11 +95,15 @@ public Object proxyRequest(final String resourceKey, final HttpServletRequest re
     RequestBody requestBody = null;
     try {
       InputStream inputStream = request.getInputStream();
-      final String contentType = request.getHeader(HttpHeaders.CONTENT_TYPE);
-      if(inputStream != null && MediaType.APPLICATION_JSON_VALUE.equals(contentType)) {
+      final String contentType = request.getContentType();
+      int contentLength = request.getContentLength();
+      if(inputStream != null && contentLength > 0) {
         requestBody = new RequestBody()
-          .setBody(FileCopyUtils.copyToByteArray(inputStream))
-          .setContentType(contentType);
+          .setBody(FileCopyUtils.copyToByteArray(inputStream));
+
+        if(StringUtils.isNotBlank(contentType)) {
+          requestBody.setContentType(contentType);
+        }
 
         context.setRequestBody(requestBody)
           .getHeaders().put(HttpHeaders.CONTENT_TYPE, contentType);

src/main/java/edu/wisc/my/restproxy/web/ResourceProxyController.java

@@ -8,6 +8,9 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.env.Environment;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
@@ -20,7 +23,7 @@
  * 
  * @author Nicholas Blair
  */
-@RestController
+@Controller
 public class ResourceProxyController {
 
   @Autowired
@@ -34,19 +37,27 @@ public class ResourceProxyController {
   void setEnv(Environment env) {
     this.env = env;
   }
+
   /**
+   * Proxies the request and then calls {@link HttpServletResponse#setStatus(int)} with the
+   * {@link HttpStatus} recieved. If the proxy response contains content it's simply returned here
+   * as an {@link Object}.
    * 
+   * @param request
+   * @param response
+   * @param key
+   * @return the body of the proxy response or null.
    */
   @RequestMapping("/{key}/**")
-  public @ResponseBody Object proxyResource(HttpServletRequest request, 
+  public  @ResponseBody Object proxyResource(HttpServletRequest request, 
       HttpServletResponse response,
       @PathVariable String key) {
-    Object result = proxyService.proxyRequest(key, request);     
-    if(result == null) {
-      response.setStatus(HttpServletResponse.SC_NOT_FOUND);
+    ResponseEntity<Object> responseEntity = proxyService.proxyRequest(key, request);   
+    if(responseEntity == null || responseEntity.getStatusCode() == null) {
+      response.setStatus(HttpStatus.NOT_FOUND.value());
       return null;
-    } else {
-      return result;
     }
+    response.setStatus(responseEntity.getStatusCode().value());
+    return responseEntity.hasBody() ? responseEntity.getBody() : null;  
   }
 }

src/test/java/edu/wisc/my/restproxy/ValidationResult.java

@@ -0,0 +1,23 @@
+/**
+ * 
+ */
+package edu.wisc.my.restproxy;
+
+/**
+ * Just an example of an object that could be retruned by rest api.
+ * @author Collin Cudd
+ */
+public class ValidationResult {
+
+  boolean success;
+  String message;
+  /**
+   * @param success
+   * @param message
+   */
+  public ValidationResult(boolean success, String message) {
+    this.success = success;
+    this.message = message;
+  }
+
+}

src/test/java/edu/wisc/my/restproxy/dao/RestProxyDaoImplTest.java

@@ -74,9 +74,6 @@ public void proxyRequest_control() {
     headers.add("Authorization", "Basic " + base64Creds);
 
     HttpEntity<String> expectedRequest = new HttpEntity<String>(headers);
-    Object expectedResponseBody = Mockito.mock(Object.class);
-    Mockito.when(expectedResponse.getBody()).thenReturn(expectedResponseBody);
-
     Mockito.when(
         restTemplate.exchange(
             Matchers.eq(context.getUri()), 
@@ -95,6 +92,6 @@ public void proxyRequest_control() {
         Matchers.eq(Object.class), 
         Matchers.eq(context.getAttributes())
     );
-    assertEquals(expectedResponseBody, proxyResponse);
+    assertEquals(expectedResponse, proxyResponse);
     }
 }

src/test/java/edu/wisc/my/restproxy/service/RestProxyServiceImplTest.java

@@ -16,11 +16,14 @@
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.mock.env.MockEnvironment;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.web.servlet.HandlerMapping;
 
 import edu.wisc.my.restproxy.ProxyRequestContext;
+import edu.wisc.my.restproxy.ValidationResult;
 import edu.wisc.my.restproxy.dao.RestProxyDao;
 
 /**
@@ -45,7 +48,7 @@ public void setup() {
    */
   @Test
   public void proxyRequest_control() {
-    final Object result = new Object();
+    final ResponseEntity<Object> result = new ResponseEntity<Object>(new Object(), HttpStatus.OK);
 
     MockHttpServletRequest request = new MockHttpServletRequest();
     request.setMethod("GET");
@@ -59,13 +62,34 @@ public void proxyRequest_control() {
     assertEquals(result, proxy.proxyRequest("control", request));
   }
 
+  /**
+   * Test simulates a proxy request which fails with a http 400 error.  
+   * An error like this could be encountered if you were to post invalid data to a form.
+   * Test verifies the HttpStatus AND the body (which likely contins validation error message) are passed back to the client.
+   */
+  @Test
+  public void proxyRequest_failsWithBadRequest() {
+    ValidationResult validationFailure = new ValidationResult(false, "you didn't check the box");
+    final ResponseEntity<Object> expectedResult = new ResponseEntity<Object>(validationFailure, HttpStatus.BAD_REQUEST);
+    MockHttpServletRequest request = new MockHttpServletRequest();
+    request.setMethod("POST");
+    request.setAttribute(HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE, "/control/foo");
+    request.setContent("{ \"hello\": \"world\" }".getBytes());
+    request.addHeader("Content-Type", "application/json");
+    env.setProperty("control.uri", "http://destination");
+    when(proxyDao.proxyRequest(any(ProxyRequestContext.class))).thenReturn(expectedResult);
+    ResponseEntity<Object> result = proxy.proxyRequest("control", request);
+    assertEquals(expectedResult, result);
+    assertEquals(validationFailure, result.getBody());
+  }
+
   /**
    * Experiment for {@link RestProxyServiceImpl#proxyRequest(String, HttpServletRequest)}, confirms
    * expected behavior when the configuration contains credentials.
    */
   @Test
   public void proxyRequest_withCredentials() {
-    final Object result = new Object();
+    final ResponseEntity<Object> result = new ResponseEntity<Object>(new Object(), HttpStatus.OK);
 
     MockHttpServletRequest request = new MockHttpServletRequest();
     request.setMethod("GET");
@@ -85,7 +109,7 @@ public void proxyRequest_withCredentials() {
    */
   @Test
   public void proxyRequest_withAdditionalHeader() {
-    final Object result = new Object();
+    final ResponseEntity<Object> result = new ResponseEntity<Object>(new Object(), HttpStatus.OK);
 
     MockHttpServletRequest request = new MockHttpServletRequest();
     request.setAttribute("wiscedupvi", "UW111A111");
@@ -105,7 +129,7 @@ public void proxyRequest_withAdditionalHeader() {
    */
   @Test
   public void proxyRequest_withAdditionalHeaders_andPlaceholders() {
-    final Object result = new Object();
+    final ResponseEntity<Object> result = new ResponseEntity<Object>(new Object(), HttpStatus.OK);
 
     MockHttpServletRequest request = new MockHttpServletRequest();
     request.setAttribute("wiscedupvi", "UW111A111");
@@ -125,7 +149,7 @@ public void proxyRequest_withAdditionalHeaders_andPlaceholders() {
    */
   @Test
   public void proxyRequest_withAdditionalPath() {
-    final Object result = new Object();
+    final ResponseEntity<Object> result = new ResponseEntity<Object>(new Object(), HttpStatus.OK);
 
     MockHttpServletRequest request = new MockHttpServletRequest();
     request.setMethod("GET");