播放控制器不接受JSON POST

Question

I am working on Play 1.2.4.
I have set up the routes like this:

POST    /index    Application.index(format:'json')

The controller is like this:

public static void index(String json) {

    Logger.info("content type: %s", request.contentType);
    Logger.info("json string: %s", json);
    MyObj obj = new Gson().fromJson(json, MyObj.class);
    ...
    ...
}

And my curl request is like this:

curl -v -H "Content-Type: application/json" -X POST -d '{"name":"John Smith","email":"email@email.com","value1":"Value one","value2":"Value two","urls":[{"url":"http://www.google.ca"},{"url":"http://www.msn.ca"}]}' http://localhost:9000/index

MyObj has the following fields:

public String name;
public String email;
public String value1;
public String value2;
public String[] urls;

However, the controller receives a NULL for input. What am I doing wrong? Can someone show me how to consume a JSON POST request and convert it to an object (in particular the array of urls)? Thanks!

Answer 1

Try changing the variable name in your method parameters from json to body.

public static void index(String body) {

    Logger.info("content type: %s", request.contentType);
    Logger.info("json string: %s", body);
    MyObj obj = new Gson().fromJson(body, MyObj.class);
    ...
    ...
}

Answer 2

You need to change this in your request:

[{"url":"http://www.google.ca"},{"url":"http://www.msn.ca"}]

For this:

["http://www.google.ca","http://www.msn.ca"]

Because your object has an array of strings, otherwise, it will assume every element in the array is an object with one field called "url" (and obviously String do not have that field)

Answer 3

My assumption would be because you are not accessing the request, and you are never inputting a value for the String which you are accessing, giving you the NULL input.

Try accessing the JSON request through the request().body().asJson(); call.

Also have a look at http://www.playframework.org/documentation/2.0.1/JavaJsonRequests

It should give you a solid idea on how to manipulate your JSON request.