无法将图片从Android上传到java服务器

Question

我一直在努力通过Android Retrofit + SpringMVC实现个人资料照片上传功能。 Java服务器无法响应Retrofit API调用。 相关代码段如下：

ApiInterface

@Multipart
@POST("user/profileImage")
Call<ResponseBody> uploadImage(@Part MultipartBody.Part image, @Part("name") RequestBody name);

uploadToServer

public void uploadToServer(){
    //Get retrofit client
    Retrofit retrofit = ApiClient.getClient();
    //Get API interface
    ApiInterface apiInterface = retrofit.create(ApiInterface.class);
    // Get image parts
    MultipartBody.Part imageParts = bitmapToMultipart(imageBitmap);
    //Get image name
    RequestBody name = RequestBody.create(MediaType.parse("text/plain"), "ProfileImage");
    //Call image upload API
    Call<ResponseBody> call = apiInterface.uploadImage(imageParts,name);
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            ResponseBody body = response.body();
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            t.printStackTrace();
        }
    });
}

bitmapToMultipart

public MultipartBody.Part bitmapToMultipart(Bitmap imageBitmap){
    File file = null;
    try {
        //create a file to write bitmap data
        file = new File(this.getCacheDir(), "imageBitmap");
        file.createNewFile();

        //Convert bitmap to byte array
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        imageBitmap.compress(Bitmap.CompressFormat.JPEG, 0 /*ignored for PNG*/, bos);
        byte[] bitmapdata = bos.toByteArray();

        //write the bytes in file
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(bitmapdata);
        fos.flush();
        fos.close();
    }catch(IOException e){
        e.printStackTrace();
    }
    RequestBody reqFile = RequestBody.create(MediaType.parse("image/*"), file);
    MultipartBody.Part body = MultipartBody.Part.createFormData("upload", file.getName(), reqFile);

    return body;
}

Java SpringMVC控制器

@Controller
@RequestMapping("/user")
public class UserController{
    @RequestMapping(value = "/profileImage", method = RequestMethod.POST)
    public  @ResponseBody String imageUploader(@RequestParam("image") MultipartFile image, @RequestBody RequestBody name)throws Exception{
        return "";
    }
}

问题是：请求甚至没有到达java服务器。

Answer 1

在你的uploadToServer（）函数中，媒体类型应该是“multipart / form-data”来代替字段名称的“text / plain”...

//Get image name
    RequestBody name = RequestBody.create(MediaType.parse("multipart/form-data"), "ProfileImage");

在bitmapToMultipart（）函数中，媒体类型应为“multipart / form-data”。 （“image / *”也应该有用，但如果不是“multipart / form-data”肯定会有效）

Refer - 如何在Retrofit 2中上传图像文件

在你的spring控制器中，你应该用@RequestParam代替@Requestbody

@Controller
@RequestMapping("/user")
public class UserController{
    @RequestMapping(value = "/profileImage", method = RequestMethod.POST)
    public  @ResponseBody String imageUploader(@RequestParam("image") MultipartFile image, @RequestParam String name)throws Exception{
        return "";
    }
}

Answer 2

请改变你的

RequestBody reqFile = RequestBody.create(MediaType.parse("image/*"), file);

至

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

即你bitmapToMultipart函数应该是，像

public MultipartBody.Part bitmapToMultipart(Bitmap imageBitmap){
    File file = null;
    try {
        //create a file to write bitmap data
        file = new File(this.getCacheDir(), "imageBitmap");
        file.createNewFile();

        //Convert bitmap to byte array
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        imageBitmap.compress(Bitmap.CompressFormat.JPEG, 0 /*ignored for PNG*/, bos);
        byte[] bitmapdata = bos.toByteArray();

        //write the bytes in file
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(bitmapdata);
        fos.flush();
        fos.close();
    }catch(IOException e){
        e.printStackTrace();
    }
    RequestBody reqFile = RequestBody.create(MediaType.parse("multipart/form-data"), file);
    MultipartBody.Part body = MultipartBody.Part.createFormData("upload", file.getName(), reqFile);

    return body;
}

Answer 3

ApiInterface

@Multipart
@POST("user/profileImage")
Call<ResponseBody> uploadImage(@Part("image") MultipartBody.Part image, @Part("name") RequestBody name);

uploadToServer

public void uploadToServer(){
    //Get retrofit client
    Retrofit retrofit = ApiClient.getClient();
    //Get API interface
    ApiInterface apiInterface = retrofit.create(ApiInterface.class);
    // Get image parts
    MultipartBody.Part imageParts = bitmapToMultipart(imageBitmap);
    //Get image name
    RequestBody name = RequestBody.create(MediaType.parse("text/plain"), "ProfileImage");
    //Call image upload API
    Call<ResponseBody> call = apiInterface.uploadImage(imageParts,name);
    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            ResponseBody body = response.body();
        }

        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            t.printStackTrace();
        }
    });
}

bitmapToMultipart

public MultipartBody.Part bitmapToMultipart(Bitmap imageBitmap){

        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        imageBitmap.compress(Bitmap.CompressFormat.JPEG, 0 /*ignored for PNG*/, bos);
        byte[] bitmapdata = bos.toByteArray();

    RequestBody reqFile = RequestBody.create(MediaType.parse("image/*"), bitmapdata);
    MultipartBody.Part body = MultipartBody.Part.createFormData("upload", "name", reqFile);

    return body;
}  

Java SpringMVC控制器

@Controller
@RequestMapping("/user")
public class UserController{
    @RequestMapping(value = "/profileImage", method = RequestMethod.POST)
    public  @ResponseBody String imageUploader(@RequestParam("image") MultipartFile image, @RequestParam String name)throws Exception{
        return "";
    }
}

Answer 4

1. 首先你要检查android客户端上传文件是OK.eg：使用压缩质量80

   imageBitmap.compress（Bitmap.CompressFormat.JPEG，80，bos）;

2. 在客户端更改MediaType和调试RequestBody有数据
3. 服务器调试检查接收请求数据