.java

public interface SampleRetrofitInterface {
@GET("/posts")
Call<List<Post>> getPostList();

@GET("/posts/{id}")
Call<Post> getSinglePost(@Path("id") int postId);

@GET("/posts/")
Call<Post> getSinglePostQuery(@Query("userId") int userId);

@PUT("/posts/{id}")
Call<Post> putSinglePost(@Path("id") int postId);

@DELETE("/posts/{id}")
Call<String> deletePost(@Path("id") int postId);

@POST("users/new")
Call<Post> createPost(@Body Post post);

Retrofit retrofit = new Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("https://jsonplaceholder.typicode.com")
.build();
}