android - Retrofit 2.0 发送文件和字符串值报错

Question

我必须使用 Retrofit 2 在 post 方法中上传图片并发送 String 数据。我正在使用流动方法来做到这一点。

@Multipart
@FormUrlEncoded
@POST("signup/step3")
Call<BasicModel> completeRegistration(
    /*All Basic Parameter*/
    @Field("mobile_no") String mobileNo,

    /*For User Image*/
    @Part MultipartBody.Part photoFile

);

但我收到以下错误。

java.lang.IllegalArgumentException: Only one encoding annotation is allowed.
         for method AllNetworkCalls.completeRegistration
         at retrofit2.ServiceMethod$Builder.methodError(ServiceMethod.java:695)
         at retrofit2.ServiceMethod$Builder.methodError(ServiceMethod.java:686)
         at retrofit2.ServiceMethod$Builder.parseMethodAnnotation(ServiceMethod.java:266)
         at retrofit2.ServiceMethod$Builder.build(ServiceMethod.java:169)
         at retrofit2.Retrofit.loadServiceMethod(Retrofit.java:166)
         at retrofit2.Retrofit$1.invoke(Retrofit.java:145)
         at java.lang.reflect.Proxy.invoke(Proxy.java:397)
         at $Proxy1.completeRegistration(Unknown Source)
         at com.sslwireless.app.Activities.SignUp.RegistrationActivity_5.completeRegistration(RegistrationActivity_5.java:244)
         at com.sslwireless.app.Activities.SignUp.RegistrationActivity_5.access$1100(RegistrationActivity_5.java:51)
         at com.sslwireless.app.Activities.SignUp.RegistrationActivity_5$5.onClick(RegistrationActivity_5.java:132)
         at android.view.View.performClick(View.java:4856)
         at android.view.View$PerformClick.run(View.java:19956)
         at android.os.Handler.handleCallback(Handler.java:739)
         at android.os.Handler.dispatchMessage(Handler.java:95)
         at android.os.Looper.loop(Looper.java:211)
         at android.app.ActivityThread.main(ActivityThread.java:5389)
         at java.lang.reflect.Method.invoke(Native Method)
         at java.lang.reflect.Method.invoke(Method.java:372)
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1020)
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:815)

还有其他方法吗？

Answer 1

使用 Retrofit 2，您需要使用 OkHttp 的 RequestBody 或 MultipartBody.Part 类并将您的文件封装到请求主体中。让我们看一下文件上传的接口(interface)定义。

public interface FileUploadService {  
    @Multipart
    @POST("upload")
    Call<ResponseBody> upload(@Part("description") RequestBody description,
                              @Part MultipartBody.Part file);
}

在 Java 文件中

private void uploadFile(Uri fileUri) {  
    // create upload service client
    FileUploadService service =
            ServiceGenerator.createService(FileUploadService.class);

    // https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooser/src/com/ipaulpro/afilechooser/utils/FileUtils.java
    // use the FileUtils to get the actual file by uri
    File file = FileUtils.getFile(this, fileUri);

    // create RequestBody instance from file
    RequestBody requestFile =
            RequestBody.create(MediaType.parse("multipart/form-data"), file);

    // MultipartBody.Part is used to send also the actual file name
    MultipartBody.Part body =
            MultipartBody.Part.createFormData("picture", file.getName(), requestFile);

    // add another part within the multipart request
    String descriptionString = "hello, this is description speaking";
    RequestBody description =
            RequestBody.create(
                    MediaType.parse("multipart/form-data"), descriptionString);

    // finally, execute the request
    Call<ResponseBody> call = service.upload(description, body);
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call,
                               Response<ResponseBody> response) {
            Log.v("Upload", "success");
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            Log.e("Upload error:", t.getMessage());
        }
    });
}