I have a AWS Lambda function written in Java, that gets triggered by an AWS API Gateway call.
I am trying to make a POST request to one of the endpoints with a JSON as payload.
curl -H "Content-Type: application/json" -X POST -d '{"firstName":"Mr", "lastName":"Awesome"}' https://someexample.execute-api.eu-central-1.amazonaws.com/beta/MethodHandlerLambda
The gateway will then detect the Content-Type and pass all request parameters (including the body) through a default template. The interesting part is this one
#set($allParams = $input.params())
{
"body-json" : $input.json('$'),
....
It is supposed to present me with a Map<String, Object> that is passed to my Java method:
public void myHandler(Map<String, Object> input, Context context){
input.keySet().forEach((key) -> {
System.out.println(key + " : " + input.get(key));
});
}
And the result should be something like this:
body-json : {"firstName":"Mr", "lastName":"Awesome"}
...
But what I am getting is this:
body-json : {firstName=Mr, lastName=Awesome}
Another possibility would be to pass the whole body as string:
"body" : $input.body
but that again just "converts" to key=value instead of key:value
How do I have to configure the template to simply pass me the body so I can use it in a JSON parser?
And again - just posting a question here on SO helps to find the answer on your own :)
In the AWS Api Gateway template I set the body to
"body-json" : $input.body
which should return the complete payload as a String.
But more importantly I read Greggs answer to his own question and changed my method to
public void myHandler(InputStream inputStream, OutputStream outputStream, Context context) throws IOException{
final ObjectMapper objectMapper = new ObjectMapper();
JsonNode json = objectMapper.readTree(inputStream);
System.out.println(json.toString());
}
So, it is sufficient to have a simple InputStream and read it as a JsonNode with whatever JSON library one prefers (I am using Jackson FasterXML). And voila, it packs all possible parameters in a single JSON (as specified by the template)
{
"body-json": {
"firstName": "Mr",
"lastName": "Awesome"
},
"params": {
...
},
"stage-variables": {
...
},
"context": {
...
}
}