带字符串响应的改造

Question

我想要对URL进行POST调用，并且作为响应，我只得到一个字符串“ ok”或“ no”。

public interface registerAPI
{
    @FormUrlEncoded
    @POST("addDevice.php")
    Call<String> insertUser(
            @Field("name") String devicename,
            @Field("username") String regid);
}

所以我只想给POST方法两个参数，我想要一个字符串。在服务器上的PHP脚本中，有类似以下内容：

<?php
if(...)
   echo "ok";
else
   echo "no";

所以我打电话给我的Android手机：

Retrofit adapter = new Retrofit.Builder()
                        .baseUrl("http://root.url.net/")
                        .addConverterFactory(GsonConverterFactory.create()) //I dont want this..
                        .build();

                registerAPI api = adapter.create(registerAPI.class);

                Call<String> call = api.insertUser(name,regid);
                call.enqueue(new Callback<String>()
                {
                    @Override
                    public void onResponse(Response<String> response, Retrofit retrofit)
                    {
                        Log.i("Error",response.message());
                    }

                    @Override
                    public void onFailure(Throwable t)
                    {
                        Log.d("Error", " Throwable is " +t.toString());

                    }
                });

因此，当我在Throwable中运行此命令时，收到以下消息：

Unable to create converter for class java.lang.String

我是否只需要为字符串响应编写自己的转换器？我该怎么做？还是有更好的方法来做到这一点？

问候

Answer 1

好的答案是编写自己的转换器。像这样：

public final class ToStringConverterFactory extends Converter.Factory {

            @Override
            public Converter<ResponseBody, ?> fromResponseBody(Type type, Annotation[] annotations) {
                //noinspection EqualsBetweenInconvertibleTypes
                if (String.class.equals(type)) {
                    return new Converter<ResponseBody, Object>() {

                        @Override
                        public Object convert(ResponseBody responseBody) throws IOException {
                            return responseBody.string();
                        }
                    };
                }

                return null;
            }

            @Override
            public Converter<?, RequestBody> toRequestBody(Type type, Annotation[] annotations) {
                //noinspection EqualsBetweenInconvertibleTypes
                if (String.class.equals(type)) {
                    return new Converter<String, RequestBody>() {

                        @Override
                        public RequestBody convert(String value) throws IOException {
                            return RequestBody.create(MediaType.parse("text/plain"), value);
                        }
                    };
                }

                return null;
            }
        }

您必须这样称呼它：

Retrofit adapter = new Retrofit.Builder()
                        .baseUrl("http://root.url.net/")
                        .addConverterFactory(new ToStringConverterFactory())
                        .build();

                registerAPI api = adapter.create(registerAPI.class);

                Call<String> call = api.insertUser(name,regid);

您会收到以下响应：

call.enqueue(new Callback<String>()
                {
                    @Override
                    public void onResponse(Response<String> response, Retrofit retrofit)
                    {
                        Log.i("http","innen: " + response.message());
                        Log.i("http","innen: " + response.body()); // here is your string!!
                    }

                    @Override
                    public void onFailure(Throwable t)
                    {
                        Log.d("http", " Throwable " +t.toString());

                    }
                });

Answer 2

@Klatschen 你的回答是对的，在 Retrofit2 中 abstarct 功能已经改变。

public final class StringConverterFactory extends Converter.Factory {
@Override
public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
    if (String.class.equals(type)) {
        return new Converter<ResponseBody, Object>() {
            @Override
            public Object convert(ResponseBody responseBody) throws IOException {
                return responseBody.string();
            }
        };
    }

    return null;
}

@Override
public Converter<?, RequestBody> requestBodyConverter(Type type,
                                                      Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
    if (String.class.equals(type)) {
        return new Converter<String, RequestBody>() {
            @Override
            public RequestBody convert(String value) throws IOException {
                return RequestBody.create(MediaType.parse("text/plain"), value);
            }
        };
    }
    return null;
}
}