如何通过 HTTP POST 方法使用 Retrofit 或 Picasso 下载图像
How to download image using Retrofit or Picasso via HTTP POST method
我有一个 HTTP post 请求，它需要一个包含以下内容的 JSON 作为请求 body:
{
"UserName":"ApiService",
"Password":"BandarAndroid",
"AndroidId":"15df3b3a90XXXXX",
"ContentId":"704",
"frame":"1"
}
向服务器请求后，我只得到一张图像作为响应（而不是任何东西（如 JSON））。
适当的图像是根据要求创建的，没有网址。
我的服务地址是：
http://xyz.website.com/api/DownloadFileForAndroid
我的回复 header 是：
cache-control →no-cache
content-length →29837
content-type →image/png
date →Mon, 09 Sep 2019 08:42:23 GMT
expires →-1
pragma →no-cache
server →Microsoft-IIS/8.5
x-aspnet-version →4.0.30319
x-powered-by →ASP.NET
不知道是用retrofit还是Picasso来拍这张照片，
in Picasso: 我无法在请求 body 中发送 JSON 的金额。
在改造中：没有 url 我无法获取照片（地址指向像 www.site.com/a.jpg 的照片）
I don't know whether to use retrofit or Picasso to get this photo
最好使用Picasso，否则如果使用Retrofit下载图像，您必须编写大量代码才能有效地加载图像.
你会很高兴知道你可以根据你的选择使用 Retrofit 和 Picasso 从 API.
加载图像
在继续示例之前，我想澄清一件事，您误以为您需要将 above-mentioned JSON 数据发送为 header 但在玩弄 API 之后，我发现它需要 JSON 作为请求 body.
例子
RemoteApi.kt
interface RemoteApi {
// Retrofit
@Streaming // Important
@POST("/api/DownloadFileForAndroid")
@Throws(Exception::class)
suspend fun getImage(@Body body: ImageRequest): ResponseBody?
companion object {
// Retrofit
fun create(): RemoteApi {
val retrofit = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("http://shop.atiafkar.ir")
.build()
return retrofit.create(RemoteApi::class.java)
}
// Picasso
fun getPicassoImageRequest(
builder : Picasso.Builder,
body: String,
url: String = "http://shop.atiafkar.ir/api/DownloadFileForAndroid"
) = builder.downloader(OkHttp3Downloader(getPicassoCallFactory(body)))
.build()
.load(url)
// Picasso
private fun getPicassoCallFactory(jsonBody : String): Call.Factory {
return Call.Factory { request ->
OkHttpClient().run {
RequestBody.create(MediaType.parse("application/json"), jsonBody).let {
newCall(request.newBuilder()
.post(it)
.addHeader("Content-Type", "application/json")
.build()
)
}
}
}
}
}
}
ImageRepository.kt
class ImageRepository(private val api: RemoteApi = RemoteApi.create()) {
companion object {
fun get() = ImageRepository()
}
// Retrofit
suspend fun downloadImage(body : ImageRequest = ImageRequest.default): Bitmap? {
return api.getImage(body)?.run {
withContext(Dispatchers.IO) {
bytes().let {
// to load bitmap efficiently follow the guideline provided by -
// https://developer.android.com/topic/performance/graphics/load-bitmap
// otherwise you may experience OutOfMemoryException
BitmapFactory.decodeByteArray(it, 0, it.size)
}
}
}
}
// Picasso
fun getPicassoImageLoader(
builder : Picasso.Builder,
body: ImageRequest = ImageRequest.default
) = RemoteApi.getPicassoImageRequest(builder, body.toJson())
}
ImageViewModel.kt
class ImageViewModel(private val repository: ImageRepository) : ViewModel() {
private val _progress = MutableLiveData<Boolean>()
val progress = _progress
// Retrofit
val liveImage = liveData {
_progress.value = true
emit(repository.downloadImage())
_progress.value = false
}
// Picasso
fun getPicassoImageLoader(builder: Picasso.Builder) = repository.getPicassoImageLoader(builder)
}
最后，
ImageActivity.kt
class ImageActivity : AppCompatActivity() {
private lateinit var dataBinding : ActivityImageBinding
private val imageViewModel by lazy { ViewModelProviders.of(this, ImageViewModelFactory()).get(ImageViewModel::class.java) }
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
dataBinding = DataBindingUtil.setContentView(this, R.layout.activity_image)
dataBinding.lifecycleOwner = this
dataBinding.viewModel = imageViewModel
// Retrofit
imageViewModel.liveImage.observe(this, Observer {
dataBinding.imageView.setImageBitmap(it)
})
// Picasso
imageViewModel.getPicassoImageLoader(Picasso.Builder(this)).into(dataBinding.imageView2)
}
}
ImageRequest.kt
data class ImageRequest(
@field:SerializedName("UserName")
val userName: String? = null,
@field:SerializedName("ContentId")
val contentId: String? = null,
@field:SerializedName("AndroidId")
val androidId: String? = null,
@field:SerializedName("Password")
val password: String? = null,
@field:SerializedName("frame")
val frame: String? = null
) {
companion object {
val default = ImageRequest(
"ApiService",
"704",
"15df3b3a90dc5688",
"BandarAndroid",
"1"
)
}
}
fun ImageRequest.toJson() : String {
return Gson().toJson(this, ImageRequest::class.java)
}
As you requested, I am converting my previous solution (Kotlin) to
Java
示例 1：毕加索
public void loadImageWithPicasso(ImageView imageView) {
Picasso.Builder builder = new Picasso.Builder(imageView.getContext());
RequestCreator picassoImageLoader = createPicassoLoader(
builder,
ImageRequest.DEFAULT_JSON_BODY,
"http://shop.atiafkar.ir/api/DownloadFileForAndroid"
);
picassoImageLoader.into(imageView);
}
public RequestCreator createPicassoLoader(Picasso.Builder builder, String body, String url) {
return builder.downloader(new OkHttp3Downloader(createPicassoCallFactory(body)))
.build()
.load(url);
}
private okhttp3.Call.Factory createPicassoCallFactory(String jsonBody) {
final OkHttpClient okHttpClient = new OkHttpClient.Builder()
.build();
final RequestBody requestBody = RequestBody.create(MediaType.parse("application/json"), jsonBody);
return new okhttp3.Call.Factory() {
@Override
public okhttp3.Call newCall(Request request) {
Request.Builder builder = request.newBuilder();
builder.post(requestBody);
builder.addHeader("Content-Type", "application/json");
return okHttpClient.newCall(builder.build());
}
};
}
示例 2：改造
public void loadImageWithRetrofit(ImageView imageView) {
final RetrofitImageLoader imageLoader = new RetrofitImageLoader(imageView);
RemoteApi api = RemoteApi.Factory.create();
api.getImage(ImageRequest.DEFAULT_BODY).enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
ResponseBody body = response.body();
if (response.isSuccessful() && body != null) {
imageLoader.execute(body.byteStream());
} else {
Log.d(TAG, "Retrofit onResponse(): CODE = [" + response.code() + "], MESSAGE = [" + response.message() + "]");
}
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
Log.d(TAG, "Retrofit onFailure(): t = [" + t + "]");
}
});
}
RetrofitImageLoader class
public class RetrofitImageLoader extends AsyncTask<InputStream, Integer, Bitmap> {
private ImageView imageView;
private RetrofitImageLoader(ImageView imageView) {
this.imageView = imageView;
}
@Override
protected Bitmap doInBackground(InputStream... inputStreams) {
return BitmapFactory.decodeStream(inputStreams[0]);
}
@Override
protected void onPostExecute(Bitmap bitmap) {
super.onPostExecute(bitmap);
imageView.setImageBitmap(bitmap);
}
}
RemoteApi interface
public interface RemoteApi {
@Streaming // Important
@POST("/api/DownloadFileForAndroid")
Call<ResponseBody> getImage(@Body ImageRequest body);
class Factory {
private static RemoteApi mInstance;
public static RemoteApi create() {
if (mInstance == null) {
mInstance = new Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("http://shop.atiafkar.ir")
.build()
.create(RemoteApi.class);
}
return mInstance;
}
}
}
ImageRequest 模型 class
public class ImageRequest{
public static final ImageRequest DEFAULT_BODY;
public static final String DEFAULT_JSON_BODY;
static {
DEFAULT_BODY = new ImageRequest();
DEFAULT_BODY.setAndroidId("15df3b3a90dc5688");
DEFAULT_BODY.setContentId("704");
DEFAULT_BODY.setFrame("1");
DEFAULT_BODY.setPassword("BandarAndroid");
DEFAULT_BODY.setUserName("ApiService");
DEFAULT_JSON_BODY = new Gson().toJson(DEFAULT_BODY, ImageRequest.class);
}
@SerializedName("UserName")
private String userName;
@SerializedName("ContentId")
private String contentId;
@SerializedName("AndroidId")
private String androidId;
@SerializedName("Password")
private String password;
@SerializedName("frame")
private String frame;
public void setUserName(String userName){
this.userName = userName;
}
public void setContentId(String contentId){
this.contentId = contentId;
}
public void setAndroidId(String androidId){
this.androidId = androidId;
}
public void setPassword(String password){
this.password = password;
}
public void setFrame(String frame){
this.frame = frame;
}
}
我有一个 HTTP post 请求，它需要一个包含以下内容的 JSON 作为请求 body:
{
"UserName":"ApiService",
"Password":"BandarAndroid",
"AndroidId":"15df3b3a90XXXXX",
"ContentId":"704",
"frame":"1"
}
向服务器请求后，我只得到一张图像作为响应（而不是任何东西（如 JSON））。 适当的图像是根据要求创建的，没有网址。 我的服务地址是：
http://xyz.website.com/api/DownloadFileForAndroid
我的回复 header 是：
cache-control →no-cache
content-length →29837
content-type →image/png
date →Mon, 09 Sep 2019 08:42:23 GMT
expires →-1
pragma →no-cache
server →Microsoft-IIS/8.5
x-aspnet-version →4.0.30319
x-powered-by →ASP.NET
不知道是用retrofit还是Picasso来拍这张照片，
in Picasso: 我无法在请求 body 中发送 JSON 的金额。
在改造中：没有 url 我无法获取照片（地址指向像 www.site.com/a.jpg 的照片）
I don't know whether to use retrofit or Picasso to get this photo
最好使用Picasso，否则如果使用Retrofit下载图像，您必须编写大量代码才能有效地加载图像.
你会很高兴知道你可以根据你的选择使用 Retrofit 和 Picasso 从 API.
加载图像在继续示例之前，我想澄清一件事，您误以为您需要将 above-mentioned JSON 数据发送为 header 但在玩弄 API 之后，我发现它需要 JSON 作为请求 body.
例子
RemoteApi.kt
interface RemoteApi {
// Retrofit
@Streaming // Important
@POST("/api/DownloadFileForAndroid")
@Throws(Exception::class)
suspend fun getImage(@Body body: ImageRequest): ResponseBody?
companion object {
// Retrofit
fun create(): RemoteApi {
val retrofit = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("http://shop.atiafkar.ir")
.build()
return retrofit.create(RemoteApi::class.java)
}
// Picasso
fun getPicassoImageRequest(
builder : Picasso.Builder,
body: String,
url: String = "http://shop.atiafkar.ir/api/DownloadFileForAndroid"
) = builder.downloader(OkHttp3Downloader(getPicassoCallFactory(body)))
.build()
.load(url)
// Picasso
private fun getPicassoCallFactory(jsonBody : String): Call.Factory {
return Call.Factory { request ->
OkHttpClient().run {
RequestBody.create(MediaType.parse("application/json"), jsonBody).let {
newCall(request.newBuilder()
.post(it)
.addHeader("Content-Type", "application/json")
.build()
)
}
}
}
}
}
}
ImageRepository.kt
class ImageRepository(private val api: RemoteApi = RemoteApi.create()) {
companion object {
fun get() = ImageRepository()
}
// Retrofit
suspend fun downloadImage(body : ImageRequest = ImageRequest.default): Bitmap? {
return api.getImage(body)?.run {
withContext(Dispatchers.IO) {
bytes().let {
// to load bitmap efficiently follow the guideline provided by -
// https://developer.android.com/topic/performance/graphics/load-bitmap
// otherwise you may experience OutOfMemoryException
BitmapFactory.decodeByteArray(it, 0, it.size)
}
}
}
}
// Picasso
fun getPicassoImageLoader(
builder : Picasso.Builder,
body: ImageRequest = ImageRequest.default
) = RemoteApi.getPicassoImageRequest(builder, body.toJson())
}
ImageViewModel.kt
class ImageViewModel(private val repository: ImageRepository) : ViewModel() {
private val _progress = MutableLiveData<Boolean>()
val progress = _progress
// Retrofit
val liveImage = liveData {
_progress.value = true
emit(repository.downloadImage())
_progress.value = false
}
// Picasso
fun getPicassoImageLoader(builder: Picasso.Builder) = repository.getPicassoImageLoader(builder)
}
最后，
ImageActivity.kt
class ImageActivity : AppCompatActivity() {
private lateinit var dataBinding : ActivityImageBinding
private val imageViewModel by lazy { ViewModelProviders.of(this, ImageViewModelFactory()).get(ImageViewModel::class.java) }
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
dataBinding = DataBindingUtil.setContentView(this, R.layout.activity_image)
dataBinding.lifecycleOwner = this
dataBinding.viewModel = imageViewModel
// Retrofit
imageViewModel.liveImage.observe(this, Observer {
dataBinding.imageView.setImageBitmap(it)
})
// Picasso
imageViewModel.getPicassoImageLoader(Picasso.Builder(this)).into(dataBinding.imageView2)
}
}
ImageRequest.kt
data class ImageRequest(
@field:SerializedName("UserName")
val userName: String? = null,
@field:SerializedName("ContentId")
val contentId: String? = null,
@field:SerializedName("AndroidId")
val androidId: String? = null,
@field:SerializedName("Password")
val password: String? = null,
@field:SerializedName("frame")
val frame: String? = null
) {
companion object {
val default = ImageRequest(
"ApiService",
"704",
"15df3b3a90dc5688",
"BandarAndroid",
"1"
)
}
}
fun ImageRequest.toJson() : String {
return Gson().toJson(this, ImageRequest::class.java)
}
As you requested, I am converting my previous solution (Kotlin) to Java
示例 1：毕加索
public void loadImageWithPicasso(ImageView imageView) {
Picasso.Builder builder = new Picasso.Builder(imageView.getContext());
RequestCreator picassoImageLoader = createPicassoLoader(
builder,
ImageRequest.DEFAULT_JSON_BODY,
"http://shop.atiafkar.ir/api/DownloadFileForAndroid"
);
picassoImageLoader.into(imageView);
}
public RequestCreator createPicassoLoader(Picasso.Builder builder, String body, String url) {
return builder.downloader(new OkHttp3Downloader(createPicassoCallFactory(body)))
.build()
.load(url);
}
private okhttp3.Call.Factory createPicassoCallFactory(String jsonBody) {
final OkHttpClient okHttpClient = new OkHttpClient.Builder()
.build();
final RequestBody requestBody = RequestBody.create(MediaType.parse("application/json"), jsonBody);
return new okhttp3.Call.Factory() {
@Override
public okhttp3.Call newCall(Request request) {
Request.Builder builder = request.newBuilder();
builder.post(requestBody);
builder.addHeader("Content-Type", "application/json");
return okHttpClient.newCall(builder.build());
}
};
}
示例 2：改造
public void loadImageWithRetrofit(ImageView imageView) {
final RetrofitImageLoader imageLoader = new RetrofitImageLoader(imageView);
RemoteApi api = RemoteApi.Factory.create();
api.getImage(ImageRequest.DEFAULT_BODY).enqueue(new Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
ResponseBody body = response.body();
if (response.isSuccessful() && body != null) {
imageLoader.execute(body.byteStream());
} else {
Log.d(TAG, "Retrofit onResponse(): CODE = [" + response.code() + "], MESSAGE = [" + response.message() + "]");
}
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
Log.d(TAG, "Retrofit onFailure(): t = [" + t + "]");
}
});
}
RetrofitImageLoader class
public class RetrofitImageLoader extends AsyncTask<InputStream, Integer, Bitmap> {
private ImageView imageView;
private RetrofitImageLoader(ImageView imageView) {
this.imageView = imageView;
}
@Override
protected Bitmap doInBackground(InputStream... inputStreams) {
return BitmapFactory.decodeStream(inputStreams[0]);
}
@Override
protected void onPostExecute(Bitmap bitmap) {
super.onPostExecute(bitmap);
imageView.setImageBitmap(bitmap);
}
}
RemoteApi interface
public interface RemoteApi {
@Streaming // Important
@POST("/api/DownloadFileForAndroid")
Call<ResponseBody> getImage(@Body ImageRequest body);
class Factory {
private static RemoteApi mInstance;
public static RemoteApi create() {
if (mInstance == null) {
mInstance = new Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl("http://shop.atiafkar.ir")
.build()
.create(RemoteApi.class);
}
return mInstance;
}
}
}
ImageRequest 模型 class
public class ImageRequest{
public static final ImageRequest DEFAULT_BODY;
public static final String DEFAULT_JSON_BODY;
static {
DEFAULT_BODY = new ImageRequest();
DEFAULT_BODY.setAndroidId("15df3b3a90dc5688");
DEFAULT_BODY.setContentId("704");
DEFAULT_BODY.setFrame("1");
DEFAULT_BODY.setPassword("BandarAndroid");
DEFAULT_BODY.setUserName("ApiService");
DEFAULT_JSON_BODY = new Gson().toJson(DEFAULT_BODY, ImageRequest.class);
}
@SerializedName("UserName")
private String userName;
@SerializedName("ContentId")
private String contentId;
@SerializedName("AndroidId")
private String androidId;
@SerializedName("Password")
private String password;
@SerializedName("frame")
private String frame;
public void setUserName(String userName){
this.userName = userName;
}
public void setContentId(String contentId){
this.contentId = contentId;
}
public void setAndroidId(String androidId){
this.androidId = androidId;
}
public void setPassword(String password){
this.password = password;
}
public void setFrame(String frame){
this.frame = frame;
}
}