Added check to avoid NPE when mapping null request body. Addresses #70

Author: sapessi

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

@@ -386,6 +386,9 @@ public String getContentType() {
 
     @Override
     public ServletInputStream getInputStream() throws IOException {
+        if (request.getBody() == null) {
+            return null;
+        }
         byte[] bodyBytes = request.getBody().getBytes();
         if (request.isBase64Encoded()) {
             bodyBytes = Base64.getMimeDecoder().decode(request.getBody());

aws-serverless-java-container-spring/src/test/java/com/amazonaws/serverless/proxy/spring/SpringAwsProxyTest.java

@@ -189,6 +189,34 @@ public void base64_binaryResponse_base64Encoding() {
         assertTrue(Base64.isBase64(response.getBody()));
     }
 
+    @Test
+    public void injectBody_populatedResponse_noException() {
+        AwsProxyRequest request = new AwsProxyRequestBuilder("/echo/request-body", "POST")
+                                          .body("This is a populated body")
+                                          .build();
+
+        AwsProxyResponse response = handler.proxy(request, lambdaContext);
+        assertNotNull(response.getBody());
+        try {
+            SingleValueModel output = objectMapper.readValue(response.getBody(), SingleValueModel.class);
+            assertEquals("true", output.getValue());
+        } catch (IOException e) {
+            e.printStackTrace();
+            fail();
+        }
+
+        AwsProxyRequest emptyReq = new AwsProxyRequestBuilder("/echo/request-body", "POST")
+                                          .build();
+        AwsProxyResponse emptyResp = handler.proxy(emptyReq, lambdaContext);
+        try {
+            SingleValueModel output = objectMapper.readValue(emptyResp.getBody(), SingleValueModel.class);
+            assertEquals(null, output.getValue());
+        } catch (IOException e) {
+            e.printStackTrace();
+            fail();
+        }
+    }
+
     @Test
     public void servletRequestEncoding_acceptEncoding_okStatusCode() {
         SingleValueModel singleValueModel = new SingleValueModel();

aws-serverless-java-container-spring/src/test/java/com/amazonaws/serverless/proxy/spring/echoapp/EchoResource.java

@@ -110,6 +110,17 @@ public SingleValueModel echoRequestURL(HttpServletRequest request) {
         return valueModel;
     }
 
+    @RequestMapping(path = "/request-body", method = RequestMethod.POST)
+    public SingleValueModel helloForPopulatedBody(@RequestBody(required = false) String input) {
+        SingleValueModel valueModel = new SingleValueModel();
+        System.out.println("Input: \"" + input + "\"");
+        if (input != null && !"null".equals(input)) {
+            valueModel.setValue("true");
+        }
+
+        return valueModel;
+    }
+
     @RequestMapping(path = "/encoded-request-uri/{encoded-var}", method = RequestMethod.GET)
     public SingleValueModel echoEncodedRequestUri(@PathVariable("encoded-var") String encodedVar) {
         SingleValueModel valueModel = new SingleValueModel();