Addresses issues #35 and #37

* Basic implementation of RequestDispatcher for AwsProxyRequest type
* More unit tests for multipart uploads and filters
* Servlet Context as well as request injection for Jersey

Author: sapessi

aws-serverless-java-container-core/pom.xml

@@ -65,6 +65,15 @@
             <version>1.10.19</version>
             <scope>test</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpmime</artifactId>
+            <version>4.5.3</version>
+            <scope>test</scope>
+        </dependency>
+
     </dependencies>
 
 </project>

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/LambdaContainerHandler.java

@@ -46,6 +46,9 @@ public abstract class LambdaContainerHandler<RequestType, ResponseType, Containe
     private ExceptionHandler<ResponseType> exceptionHandler;
 
 
+    protected Context lambdaContext;
+
+
     //-------------------------------------------------------------
     // Constructors
     //-------------------------------------------------------------
@@ -85,6 +88,7 @@ protected abstract void handleRequest(ContainerRequestType containerRequest, Con
      * @return A valid response type
      */
     public ResponseType proxy(RequestType request, Context context) {
+        lambdaContext = context;
         try {
             SecurityContext securityContext = securityContextWriter.writeSecurityContext(request, context);
             CountDownLatch latch = new CountDownLatch(1);
@@ -98,10 +102,6 @@ public ResponseType proxy(RequestType request, Context context) {
             return responseWriter.writeResponse(containerResponse, context);
         } catch (Exception e) {
             context.getLogger().log("Error while handling request: " + e.getMessage());
-
-            /*for (StackTraceElement el : e.getStackTrace()) {
-                context.getLogger().log(el.toString());
-            }*/
             e.printStackTrace();
 
             return exceptionHandler.handle(e);

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsHttpServletRequest.java

@@ -23,7 +23,13 @@
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
-import java.util.*;
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 
@@ -56,6 +62,9 @@ public abstract class AwsHttpServletRequest implements HttpServletRequest {
 
     private Context lambdaContext;
     private Map<String, Object> attributes;
+    private ServletContext servletContext;
+
+    protected DispatcherType dispatcherType;
 
 
     //-------------------------------------------------------------
@@ -72,6 +81,7 @@ public abstract class AwsHttpServletRequest implements HttpServletRequest {
         attributes = new HashMap<>();
     }
 
+
     //-------------------------------------------------------------
     // Implementation - HttpServletRequest
     //-------------------------------------------------------------
@@ -119,6 +129,7 @@ public boolean isRequestedSessionIdFromURL() {
 
 
     @Override
+    @Deprecated
     public boolean isRequestedSessionIdFromUrl() {
         return false;
     }
@@ -185,7 +196,7 @@ public int getLocalPort() {
 
     @Override
     public ServletContext getServletContext() {
-        return AwsServletContext.getInstance(lambdaContext);
+        return servletContext;
     }
 
 
@@ -213,6 +224,19 @@ public DispatcherType getDispatcherType() {
     }
 
 
+    //-------------------------------------------------------------
+    // Methods - Getter/Setter
+    //-------------------------------------------------------------
+
+    public void setDispatcherType(DispatcherType type) {
+        dispatcherType = type;
+    }
+
+    public void setServletContext(ServletContext context) {
+        servletContext = context;
+    }
+
+
     //-------------------------------------------------------------
     // Methods - Protected
     //-------------------------------------------------------------
@@ -223,7 +247,6 @@ public DispatcherType getDispatcherType() {
      * @return An array of Cookie objects from the header
      */
     protected Cookie[] parseCookieHeaderValue(String headerValue) {
-
         List<Map.Entry<String, String>> parsedHeaders = this.parseHeaderValue(headerValue);
 
         return parsedHeaders.stream()
@@ -232,6 +255,7 @@ protected Cookie[] parseCookieHeaderValue(String headerValue) {
                             .toArray(Cookie[]::new);
     }
 
+
     /**
      * Given a map of key/values query string parameters from API Gateway, creates a query string as it would have
      * been in the original url.

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsHttpServletResponse.java

@@ -188,6 +188,7 @@ public void setStatus(int i) {
 
 
     @Override
+    @Deprecated
     public void setStatus(int i, String s) {
         statusCode = i;
         statusMessage = s;

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsLambdaServletContainerHandler.java

@@ -17,9 +17,12 @@
 import com.amazonaws.serverless.proxy.internal.RequestReader;
 import com.amazonaws.serverless.proxy.internal.ResponseWriter;
 import com.amazonaws.serverless.proxy.internal.SecurityContextWriter;
+import com.amazonaws.services.lambda.runtime.Context;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
@@ -28,6 +31,8 @@
  * Abstract extension of the code <code>LambdaContainerHandler</code> object that adds protected variables for the
  * <code>ServletContext</code> and <code>FilterChainManager</code>. This object should be extended by the framework-specific
  * implementations that want to support the servlet 3.1 specs.
+ *
+ * Because Lambda only allows one event per container at a time, this object also acts as the <code>RequestDispatcher</code>
  * @param <RequestType>
  * @param <ResponseType>
  * @param <ContainerRequestType>
@@ -42,14 +47,13 @@ public abstract class AwsLambdaServletContainerHandler<RequestType, ResponseType
     // Variables - Private
     //-------------------------------------------------------------
 
-    private FilterChainManager filterChainManager;
+    protected ServletContext servletContext;
 
     //-------------------------------------------------------------
     // Variables - Protected
     //-------------------------------------------------------------
-
-    protected ServletContext servletContext;
     protected StartupHandler startupHandler;
+    private FilterChainManager<AwsServletContext> filterChainManager;
 
 
     //-------------------------------------------------------------
@@ -63,30 +67,43 @@ protected AwsLambdaServletContainerHandler(RequestReader<RequestType, ContainerR
         super(requestReader, responseWriter, securityContextWriter, exceptionHandler);
     }
 
-
     //-------------------------------------------------------------
-    // Methods - Getter/Setter
+    // Methods - Public
     //-------------------------------------------------------------
 
     /**
-     * Returns the current ServletContext. If the framework implementation does not set the value for
-     * servlet context this method will return null.
-     * @return The initialized servlet context if the framework-specific implementation requires one, otherwise null
+     * Fowards a request to the existing framework container. This is called by the <code>AwsProxyRequestDispatcher</code> object
+     * @param servletRequest The modified request object with the new request path
+     * @param servletResponse The original servlet response
+     * @throws ServletException
+     * @throws IOException
      */
-    public ServletContext getServletContext() {
-        return servletContext;
+    public void forward(ContainerRequestType servletRequest, ContainerResponseType servletResponse)
+            throws ServletException, IOException {
+        try {
+            handleRequest(servletRequest, servletResponse, lambdaContext);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new ServletException(e);
+        }
     }
 
 
     /**
-     * Sets the ServletContext in the handler and initialized a new <code>FilterChainManager</code>
-     * @param context An initialized ServletContext
+     * Includes a request to the existing framework container. This is called by the <code>AwsProxyRequestDispatcher</code> object
+     * @param servletRequest The modified request object with the new request path
+     * @param servletResponse The original servlet response
+     * @throws ServletException
+     * @throws IOException
      */
-    protected void setServletContext(final ServletContext context) {
-        servletContext = context;
-        // We assume custom implementations of the RequestWriter for HttpServletRequest will reuse
-        // the existing AwsServletContext object since it has no dependencies other than the Lambda context
-        filterChainManager = new AwsFilterChainManager((AwsServletContext)context);
+    public void include(ContainerRequestType servletRequest, ContainerResponseType servletResponse)
+            throws ServletException, IOException {
+        try {
+           handleRequest(servletRequest, servletResponse, lambdaContext);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new ServletException(e);
+        }
     }
 
 
@@ -111,6 +128,43 @@ public void onStartup(final StartupHandler h) {
         startupHandler = h;
     }
 
+    @Override
+    protected void handleRequest(ContainerRequestType containerRequest, ContainerResponseType containerResponse, Context lambdaContext)
+            throws Exception {
+        // The servlet context should not be linked to a specific request object, only to the Lambda
+        // context so we only set it once.
+        // TODO: In the future, if we decide to support multiple servlets/contexts in an instance we only need to modify this method
+        if (getServletContext() == null) {
+            setServletContext(new AwsServletContext(lambdaContext, this));
+        }
+    }
+
+
+    //-------------------------------------------------------------
+    // Methods - Getter/Setter
+    //-------------------------------------------------------------
+
+    /**
+     * Returns the current ServletContext. If the framework implementation does not set the value for
+     * servlet context this method will return null.
+     * @return The initialized servlet context if the framework-specific implementation requires one, otherwise null
+     */
+    public ServletContext getServletContext() {
+        return servletContext;
+    }
+
+
+    /**
+     * Sets the ServletContext in the handler and initialized a new <code>FilterChainManager</code>
+     * @param context An initialized ServletContext
+     */
+    protected void setServletContext(final ServletContext context) {
+        servletContext = context;
+        // We assume custom implementations of the RequestWriter for HttpServletRequest will reuse
+        // the existing AwsServletContext object since it has no dependencies other than the Lambda context
+        filterChainManager = new AwsFilterChainManager((AwsServletContext)context);
+    }
+
 
     //-------------------------------------------------------------
     // Methods - Protected

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsProxyHttpServletRequest.java

@@ -18,6 +18,7 @@
 
 import org.apache.commons.fileupload.FileItem;
 import org.apache.commons.fileupload.FileUploadException;
+import org.apache.commons.fileupload.disk.DiskFileItemFactory;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
 
 import javax.servlet.AsyncContext;
@@ -89,6 +90,10 @@ public AwsProxyHttpServletRequest(AwsProxyRequest awsProxyRequest, Context lambd
         this.multipartFormParameters = getMultipartFormParametersMap();
     }
 
+    public AwsProxyRequest getAwsProxyRequest() {
+        return this.request;
+    }
+
 
     //-------------------------------------------------------------
     // Implementation - HttpServletRequest
@@ -579,11 +584,11 @@ public boolean isSecure() {
 
     @Override
     public RequestDispatcher getRequestDispatcher(String s) {
-        return null;
+        return getServletContext().getRequestDispatcher(s);
     }
 
-
     @Override
+    @Deprecated
     public String getRealPath(String s) {
         // we are in an archive on a remote server
         return null;
@@ -655,7 +660,7 @@ private Map<String, Part> getMultipartFormParametersMap() {
 
         Map<String, Part> output = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
-        ServletFileUpload upload = new ServletFileUpload();
+        ServletFileUpload upload = new ServletFileUpload(new DiskFileItemFactory());
         try {
             List<FileItem> items = upload.parseRequest(this);
             for (FileItem item : items) {

aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/internal/servlet/AwsProxyHttpServletRequestReader.java

@@ -36,9 +36,13 @@ public AwsProxyHttpServletRequest readRequest(AwsProxyRequest request, SecurityC
         servletRequest.setAttribute(API_GATEWAY_CONTEXT_PROPERTY, request.getRequestContext());
         servletRequest.setAttribute(API_GATEWAY_STAGE_VARS_PROPERTY, request.getStageVariables());
         servletRequest.setAttribute(LAMBDA_CONTEXT_PROPERTY, lambdaContext);
+
         return servletRequest;
     }
 
+    //-------------------------------------------------------------
+    // Methods - Protected
+    //-------------------------------------------------------------
 
     @Override
     protected Class<? extends AwsProxyRequest> getRequestClass() {