Proof-of-concept of Spring Boot, Servlet API, and Spring MVC support

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

@@ -15,6 +15,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 
+import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -31,7 +32,7 @@ public class AwsProxyRequest {
     private String resource;
     private ApiGatewayRequestContext requestContext;
     private Map<String, String> queryStringParameters;
-    private Map<String, String> headers;
+    private Map<String, String> headers = new HashMap<>(); // avoid NPE
     private Map<String, String> pathParameters;
     private String httpMethod;
     private Map<String, String> stageVariables;
@@ -105,7 +106,11 @@ public Map<String, String> getHeaders() {
 
 
     public void setHeaders(Map<String, String> headers) {
-        this.headers = headers;
+        if (null != headers) {
+            this.headers = headers;
+        } else {
+            this.headers.clear();
+        }
     }
 
 

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

@@ -12,6 +12,8 @@
  */
 package com.amazonaws.serverless.proxy.internal.servlet;
 
+import com.amazonaws.serverless.proxy.internal.RequestReader;
+import com.amazonaws.serverless.proxy.internal.model.ApiGatewayRequestContext;
 import com.amazonaws.serverless.proxy.internal.model.ContainerConfig;
 import com.amazonaws.services.lambda.runtime.Context;
 
@@ -24,6 +26,7 @@
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
+import javax.servlet.http.HttpSessionContext;
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.net.URLEncoder;
@@ -68,6 +71,7 @@ public abstract class AwsHttpServletRequest implements HttpServletRequest {
     private Context lambdaContext;
     private Map<String, Object> attributes;
     private ServletContext servletContext;
+    private AwsHttpSession session;
 
     protected DispatcherType dispatcherType;
 
@@ -101,13 +105,17 @@ public String getRequestedSessionId() {
 
     @Override
     public HttpSession getSession(boolean b) {
-        return null;
+        if (b && null == this.session) {
+            ApiGatewayRequestContext requestContext = (ApiGatewayRequestContext) getAttribute(RequestReader.API_GATEWAY_CONTEXT_PROPERTY);
+            this.session = new AwsHttpSession(requestContext.getRequestId());
+        }
+        return this.session;
     }
 
 
     @Override
     public HttpSession getSession() {
-        return null;
+        return this.session;
     }
 
 

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

@@ -53,6 +53,7 @@ public class AwsHttpServletResponse
     private int statusCode;
     private String statusMessage;
     private String responseBody;
+    private PrintWriter writer;
     private ByteArrayOutputStream bodyOutputStream = new ByteArrayOutputStream();
     private CountDownLatch writersCountDownLatch;
     private AwsHttpServletRequest request;
@@ -316,7 +317,10 @@ public void close()
 
     @Override
     public PrintWriter getWriter() throws IOException {
-        return new PrintWriter(bodyOutputStream);
+        if (null == writer) {
+            writer = new PrintWriter(bodyOutputStream);
+        }
+        return writer;
     }
 
 
@@ -358,7 +362,11 @@ public int getBufferSize() {
 
     @Override
     public void flushBuffer() throws IOException {
+        if (null != writer) {
+            writer.flush();
+        }
         responseBody = new String(bodyOutputStream.toByteArray());
+        log.debug("Response buffer flushed with {} bytes, latch={}", responseBody.length(), writersCountDownLatch.getCount());
         isCommitted = true;
         writersCountDownLatch.countDown();
     }

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

@@ -0,0 +1,111 @@
+package com.amazonaws.serverless.proxy.internal.servlet;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpSession;
+import javax.servlet.http.HttpSessionContext;
+import java.util.Enumeration;
+
+public class AwsHttpSession implements HttpSession {
+
+    private static final Logger log = LoggerFactory.getLogger(AwsHttpSession.class);
+    private String id;
+
+    /**
+     * @param id API gateway request ID.
+     */
+    public AwsHttpSession(String id) {
+        if (null == id) {
+            throw new RuntimeException("HTTP session id (from request ID) cannot be null");
+        }
+        log.debug("Creating session " + id);
+        this.id = id;
+    }
+
+    @Override
+    public long getCreationTime() {
+        return 0;
+    }
+
+    @Override
+    public String getId() {
+        return id;
+    }
+
+    @Override
+    public long getLastAccessedTime() {
+        return 0;
+    }
+
+    @Override
+    public ServletContext getServletContext() {
+        return null;
+    }
+
+    @Override
+    public void setMaxInactiveInterval(int interval) {
+
+    }
+
+    @Override
+    public int getMaxInactiveInterval() {
+        return 0;
+    }
+
+    @Override
+    public HttpSessionContext getSessionContext() {
+        return null;
+    }
+
+    @Override
+    public Object getAttribute(String name) {
+        return null;
+    }
+
+    @Override
+    public Object getValue(String name) {
+        return null;
+    }
+
+    @Override
+    public Enumeration<String> getAttributeNames() {
+        return null;
+    }
+
+    @Override
+    public String[] getValueNames() {
+        return new String[0];
+    }
+
+    @Override
+    public void setAttribute(String name, Object value) {
+
+    }
+
+    @Override
+    public void putValue(String name, Object value) {
+
+    }
+
+    @Override
+    public void removeAttribute(String name) {
+
+    }
+
+    @Override
+    public void removeValue(String name) {
+
+    }
+
+    @Override
+    public void invalidate() {
+
+    }
+
+    @Override
+    public boolean isNew() {
+        return false;
+    }
+}

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

@@ -22,6 +22,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.servlet.Servlet;
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -176,11 +177,13 @@ protected void setServletContext(final ServletContext context) {
      * Applies the filter chain in the request lifecycle
      * @param request The Request object. This must be an implementation of HttpServletRequest
      * @param response The response object. This must be an implementation of HttpServletResponse
+     * @param servlet Servlet at the end of the chain (optional).
      * @throws IOException
      * @throws ServletException
      */
-    protected void doFilter(ContainerRequestType request, ContainerResponseType response) throws IOException, ServletException {
-        FilterChainHolder chain = filterChainManager.getFilterChain(request);
+    protected void doFilter(ContainerRequestType request, ContainerResponseType response, Servlet servlet) throws IOException, ServletException {
+        FilterChainHolder chain = filterChainManager.getFilterChain(request, servlet);
+        log.debug("FilterChainHolder.doFilter {}", chain);
         chain.doFilter(request, response);
     }
 

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

@@ -196,9 +196,13 @@ public String getPathTranslated() {
     }
 
 
+    /**
+     * In AWS API Gateway, stage is never given as part of the path.
+     * @return
+     */
     @Override
     public String getContextPath() {
-        return request.getRequestContext().getStage();
+        return "";
     }
 
 
@@ -228,7 +232,7 @@ public Principal getUserPrincipal() {
 
     @Override
     public String getRequestURI() {
-        return request.getPath();
+        return (getContextPath().isEmpty() ? "" : "/" + getContextPath()) + request.getPath();
     }
 
 

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

@@ -34,6 +34,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.MalformedURLException;
+import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.nio.file.Files;
@@ -141,9 +142,16 @@ public int getEffectiveMinorVersion() {
     @Override
     public String getMimeType(String s) {
         try {
-            return Files.probeContentType(Paths.get(s));
+
+            if (s.startsWith("file:")) { // Support paths such as file:/D:/something/hello.txt
+                return Files.probeContentType(Paths.get(URI.create(s)));
+            } else if (s.startsWith("/")) { // Support paths such as file:/D:/something/hello.txt
+                    return Files.probeContentType(Paths.get(URI.create("file://" + s)));
+            } else {
+                return Files.probeContentType(Paths.get(s));
+            }
         } catch (IOException e) {
-            log.warn("Could not find content type for filter", e);
+            log.warn("Could not find content type for file {}", s, e);
             return null;
         }
     }
@@ -364,6 +372,8 @@ public FilterRegistration.Dynamic addFilter(String name, Filter filter) {
         // filter already exists, we do nothing
         if (filters.containsKey(name)) {
             return null;
+        } else {
+            log.debug("Adding filter '{}' from {}", name, filter);
         }
 
         FilterHolder newFilter = new FilterHolder(name, filter, this);
@@ -376,6 +386,7 @@ public FilterRegistration.Dynamic addFilter(String name, Filter filter) {
     @Override
     public FilterRegistration.Dynamic addFilter(String name, Class<? extends Filter> filterClass) {
         try {
+            log.debug("Adding filter '{}' from {}", name, filterClass.getName());
             Filter newFilter = createFilter(filterClass);
             return addFilter(name, newFilter);
         } catch (ServletException e) {