Retrofit: what is different between @Field and @Body

Question

In some post request, I don't know when to use @Field, when to use @Body. Like whats the difference between:

@POST("users/register")     Call<String> register(@Body RequestBody registerRequest); 

and:

@POST("users/register")     Call<String> register(@Field String id, @Field String pass); 

Can I use @Body instead of @Field, and reverse ? If not, why ? And how to know this case use @Body, other case use @Field ?

Can you please give me some case and explain, thank you.

Answer 1

@Body – Sends Java objects as request body.

@Field – send data as form-urlencoded. This requires a @FormUrlEncoded annotation attached with the method. The @Field parameter works only with a POST. @Field requires a mandatory parameter. In cases when @Field is optional, we can use @Query instead and pass a null value.

Answer 2

Both are used for posting data only, but they have following difference -

The @Body annotation defines a single request body.

    interface Foo {        @POST("/jayson")        FooResponse postJson(@Body FooRequest body);     } 

That means if you are using @Body, it should be only parameter. It is helpful when you have already a JsonObject and you want to send it as it with you api call.

Another way is, you can send data using @Field and send the Place object as a JSON string.

@POST("/post/addphoto/")     public void addImage(@Field("image_url") String url, @Field("caption") String caption, @Field("google_place_id") String placeId, @Field("facebook_place") String place, Callback<UploadCallBack> response); 

Hope it will help... :-)