Grails: Accessing the request paramters without wiping them out

Question

According to the document on command objects and data binding. Once you read the params object, that object can never be reused again.

From the documentation:

Binding The Request Body To Command Objects http://grails.org/doc/2.3.x/guide/theWebLayer.html#commandObjects

Note that the body of the request is being parsed to make that work. Any attempt to read the body of the request after that will fail since the corresponding input stream will be empty. The controller action can either use a command object or it can parse the body of the request on its own (either directly, or by referring to something like request.JSON), but cannot do both.

I'm trying to view the parameters within a filter (which is hit before the controller is requested). Would logging the parameters to a log cause the controller to get a null param object? From the documentation that looks to be the case. However, how can I get access to the params without wiping them out in the filter?

You may be confusing the request body with request parameters. The body is an InputStream so once it is read, you are at the end of the stream so it can't be read again. Request parameters can be accessed repeatedly, as many times as it makes sense. — Jeff Scott Brown

Jeff Scott Brown Jeff Scott Brown · Accepted Answer · 2014-11-26T20:39:21

Once you read the params object, that object can never be reused again.

That is not correct. You can read request parameters over and over again. What cannot be read over and over again is the body of the request. The body and the request parameters are 2 different things.

Grails: Accessing the request paramters without wiping them out

1 Answers