Unable to bind requestParameter to @ModelAttribute form in serverless ~ Spring boot2

[1tkd]

• Framework version: aws-serverless-java-container-springboot2 1.4
• Implementations: Spring Boot2 (2.1.8)

Scenario

I send a POST request to aws lambda via api gateway.

Expected behavior

In the RequestMapping method,
the request parameter was mapped to form.

Actual behavior

In the RequestMapping method,
i got null from form object.

Steps to reproduce

1. maven build
   test project

2. create lambda function
   runtime:java11
   handler:contract.StreamLambdaHandler

3. create api gateway
   api type:rest
   /{PROXY+}/ANY
   integration type:lambda function

4. deloy api gateway

5. access via web browser
   (http://~/(stage)/start)

6. input some string to v1 input field

7. press submit

8. check v2 input filed

Full log output

START RequestId: f5fb028b-4ad5-42d3-b9ef-d6a37e90c0a6 Version: $LATEST
03:37:23.916 [main] INFO com.amazonaws.serverless.proxy.internal.LambdaContainerHandler - Starting Lambda Container Handler
.   ____          _            __ _ _
/\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/  ___)| |_)| | | | | || (_| |  ) ) ) )
'  |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot ::        (v2.1.8.RELEASE)
2020-04-23 03:37:26.084  INFO 8 --- [           main] lambdainternal.AWSLambda                 : Starting AWSLambda on 169.254.142.165 with PID 8 (/var/runtime/lib/aws-lambda-java-runtime-0.2.0.jar started by sbx_user1051 in /var/task)
2020-04-23 03:37:26.085  INFO 8 --- [           main] lambdainternal.AWSLambda                 : No active profile set, falling back to default profiles: default
2020-04-23 03:37:28.354  INFO 8 --- [           main] c.a.s.p.i.servlet.AwsServletContext      : Initializing Spring embedded WebApplicationContext
2020-04-23 03:37:28.354  INFO 8 --- [           main] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2211 ms
2020-04-23 03:37:28.773  WARN 8 --- [           main] org.thymeleaf.templatemode.TemplateMode  : [THYMELEAF][main] Template Mode 'HTML5' is deprecated. Using Template Mode 'HTML' instead.
2020-04-23 03:37:30.275  INFO 8 --- [           main] lambdainternal.AWSLambda                 : Started AWSLambda in 5.583 seconds (JVM running for 7.226)
2020-04-23 03:37:30.358  INFO 8 --- [           main] c.a.s.p.i.servlet.AwsServletContext      : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-04-23 03:37:30.358  INFO 8 --- [           main] o.s.web.servlet.DispatcherServlet        : Initializing Servlet 'dispatcherServlet'
2020-04-23 03:37:30.375  INFO 8 --- [           main] o.s.web.servlet.DispatcherServlet        : Completed initialization in 17 ms
2020-04-23 03:37:31.737  INFO 8 --- [           main] c.a.s.p.internal.LambdaContainerHandler  : 211.9.58.241 - [23/04/2020:03:37:22Z] "POST /write HTTP/1.1" 200 358 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.113 Safari/537.36" combined
END RequestId: f5fb028b-4ad5-42d3-b9ef-d6a37e90c0a6
REPORT RequestId: f5fb028b-4ad5-42d3-b9ef-d6a37e90c0a6	Duration: 1438.57 ms	Billed Duration: 1500 ms	Memory Size: 1536 MB	Max Memory Used: 219 MB	Init Duration: 7281.49 ms	
START RequestId: 950d7ed5-2d17-46be-8069-d0ac0afedfb0 Version: $LATEST
2020-04-23 03:37:41.312  INFO 8 --- [           main] c.a.s.p.internal.LambdaContainerHandler  : 211.9.58.241 - [23/04/2020:03:37:41Z] "POST /write HTTP/1.1" 200 355 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.113 Safari/537.36" combined
END RequestId: 950d7ed5-2d17-46be-8069-d0ac0afedfb0
REPORT RequestId: 950d7ed5-2d17-46be-8069-d0ac0afedfb0	Duration: 8.31 ms	Billed Duration: 100 ms	Memory Size: 1536 MB	Max Memory Used: 219 MB	

[sapessi]

Hey @1tkd, can you share some sample code to help us replicate?

[1tkd]

Thanks for helping.
All codes is here

Controller

@Controller
@EnableWebMvc
public class HelloController {
	@GetMapping(value = "/start", produces="text/html;charset=UTF-8")
	public String getStart(@ModelAttribute HelloForm helloForm) {

		return "startApp";
	}

	@RequestMapping(value = "/write", method = RequestMethod.POST, produces="text/plain;charset=UTF-8")
	public String show(@ModelAttribute HelloForm helloForm, HttpServletRequest req) {
		helloForm.setVal2("form:"+(helloForm.getVal1()==null?"isNull":helloForm.getVal1()) + " req:"+req.getParameter("val1"));
		
		return "startApp";
	}
}

Form

@Data
public class HelloForm implements Serializable {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	String val1;
	String val2;
	
}

Template

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8" />

<title>Thymeleaf</title>
</head>
<body>
  <form th:action="@{write}" method="post" th:object="${helloForm}">
  v1:  <input type="text" th:field="*{val1}" ><br>
  v2:  <input type="text" th:field="*{val2}" ><br>
  <input type="submit" value="submit">
  </form>
</body>
</html>

[fabricemarchal]

Any workaround for this issue? Got the same problem when posting application/x-www-form-urlencoded on ApiGateway :
@ModeAttribute is null.

[deki]

Sorry for the late response.

You need to define a mapping for application/x-www-form-urlencoded on ApiGateway.

This forum post https://forums.aws.amazon.com/thread.jspa?messageID=663593&tstart=0#663593 describe a similar configuration. See also https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-mapping-template-reference.html#input-variable-reference in the documentation.

[1tkd]

Thanks for the response.
Am I correct in my understanding of the following?

In the case of aws-serverless-java-container-springboot, I need to convert the request to json format, as shown in the link, in order to set it to ModelAttribute.

As a supplementary note, the data in application/x-www-form-urlencoded is available from HttpServletRequest.

[deki]

@1tkd please ignore my previous commit, this is only valid if you are not using proxy integration. Sorry, I should have initially read your description more carefully.

I deployed your sample after adding the following properties to application.yml:

logging.level.org.springframework.web: TRACE
spring.mvc.log-request-details: true

Comparing the output of the Lambda execution in CloudWatch
o.s.web.servlet.DispatcherServlet : POST "/write", parameters={val1:[test]}

with local execution on Tomcat
o.s.web.servlet.DispatcherServlet : POST "/write", parameters={val1:[test], val2:[]}

indicates that empty parameters are missing. Will add a testcase and proposed fix for that.