android studiot图片上传下载

Android Studio中实现图片的上传下载可以通过以下步骤完成：

1.导入相关依赖库，例如OkHttp、Retrofit等。

2.在AndroidManifest.xml文件中添加网络权限：

<uses-permission android:name="android.permission.INTERNET" />

3.创建一个接口，定义上传下载的方法，例如：

public interface ApiService {
    //上传图片
    @Multipart
    @POST("upload")
    Call<ResponseBody> uploadImage(@Part MultipartBody.Part image);

    //下载图片
    @GET("download/{fileName}")
    Call<ResponseBody> downloadImage(@Path("fileName") String fileName);
}

4.创建一个Retrofit实例，并调用接口中的方法：

//创建Retrofit实例
Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("http://your.api.url/")
        .addConverterFactory(GsonConverterFactory.create())
        .build();

//创建ApiService实例
ApiService apiService = retrofit.create(ApiService.class);

//上传图片
File file = new File("your/image/path");
RequestBody requestBody = RequestBody.create(MediaType.parse("multipart/form-data"), file);
MultipartBody.Part image = MultipartBody.Part.createFormData("image", file.getName(), requestBody);
Call<ResponseBody> call = apiService.uploadImage(image);
call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        //上传成功
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        //上传失败
    }
});

//下载图片
Call<ResponseBody> call = apiService.downloadImage("your_image_file_name");
call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        //下载成功
        InputStream inputStream = response.body().byteStream();
        Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
        //显示图片
        imageView.setImageBitmap(bitmap);
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        //下载失败
    }
});