Question

我在我的Android应用程序中使用OKHTTP客户端进行联网。

This示例显示了如何上传二进制文件。我想知道如何使用OKHTTP客户端获取二进制文件下载的输入流。

以下是该示例的列表：

public class InputStreamRequestBody extends RequestBody {

    private InputStream inputStream;
    private MediaType mediaType;

    public static RequestBody create(final MediaType mediaType, 
            final InputStream inputStream) {
        return new InputStreamRequestBody(inputStream, mediaType);
    }

    private InputStreamRequestBody(InputStream inputStream, MediaType mediaType) {
        this.inputStream = inputStream;
        this.mediaType = mediaType;
    }

    @Override
    public MediaType contentType() {
        return mediaType;
    }

    @Override
    public long contentLength() {
        try {
            return inputStream.available();
        } catch (IOException e) {
            return 0;
        }
    }

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        Source source = null;
        try {
            source = Okio.source(inputStream);
            sink.writeAll(source);
        } finally {
            Util.closeQuietly(source);
        }
    }
}

简单获取请求的当前代码是：

OkHttpClient client = new OkHttpClient();
request = new Request.Builder().url("URL string here")
                    .addHeader("X-CSRFToken", csrftoken)
                    .addHeader("Content-Type", "application/json")
                    .build();
response = getClient().newCall(request).execute();

现在如何将响应转换为InputStream。类似于Apache HTTP Client响应的类似OkHttp响应的内容：

InputStream is = response.getEntity().getContent();

修改

从下面接受的答案。我修改过的代码：

request = new Request.Builder().url(urlString).build();
response = getClient().newCall(request).execute();

InputStream is = response.body().byteStream();

BufferedInputStream input = new BufferedInputStream(is);
OutputStream output = new FileOutputStream(file);

byte[] data = new byte[1024];

long total = 0;

while ((count = input.read(data)) != -1) {
    total += count;
    output.write(data, 0, count);
}

output.flush();
output.close();
input.close();

Answer 1

为了它的价值，我建议okio response.body().source()（因为OkHttp本身已经支持它），以便更轻松地操作大量数据下载文件时可以来。

@Override
public void onResponse(Call call, Response response) throws IOException {
    File downloadedFile = new File(context.getCacheDir(), filename);
    BufferedSink sink = Okio.buffer(Okio.sink(downloadedFile));
    sink.writeAll(response.body().source());
    sink.close();
}

与InputStream相比，文档中的一些优点：

此接口在功能上等同于InputStream。   当消费数据是异构时，InputStream需要多个层：用于原始值的DataInputStream，用于缓冲的BufferedInputStream和用于字符串的InputStreamReader。该类使用BufferedSource来实现上述所有功能。   Source避免了不可能实现的available（）方法。相反，调用者指定它们需要多少字节。

Source省略了InputStream跟踪的不安全组成标记和重置状态;呼叫者只是缓冲他们需要的东西。

实现源代码时，您不必担心单字节读取方法难以有效实现并返回257个可能值中的一个。

源码有一个更强大的跳过方法：BufferedSource.skip（long）不会过早返回。

Answer 2

从OKHTTP获取ByteStream

我一直在 OkHttp 的文档中挖掘你需要这样做

使用此方法：

response.body（）。byteStream（）将返回一个InputStream

所以你可以简单地使用BufferedReader或任何其他替代

OkHttpClient client = new OkHttpClient();
request = new Request.Builder().url("URL string here")
                     .addHeader("X-CSRFToken", csrftoken)
                     .addHeader("Content-Type", "application/json")
                     .build();
response = getClient().newCall(request).execute();

InputStream in = response.body().byteStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
String result, line = reader.readLine();
result = line;
while((line = reader.readLine()) != null) {
    result += line;
}
System.out.println(result);
response.body().close();

Answer 3

下载的最佳选择（基于源代码＆＃34; okio＆＃34;）

private void download(@NonNull String url, @NonNull File destFile) throws IOException {
    Request request = new Request.Builder().url(url).build();
    Response response = okHttpClient.newCall(request).execute();
    ResponseBody body = response.body();
    long contentLength = body.contentLength();
    BufferedSource source = body.source();

    BufferedSink sink = Okio.buffer(Okio.sink(destFile));
    Buffer sinkBuffer = sink.buffer();

    long totalBytesRead = 0;
    int bufferSize = 8 * 1024;
    for (long bytesRead; (bytesRead = source.read(sinkBuffer, bufferSize)) != -1; ) {
        sink.emit();
        totalBytesRead += bytesRead;
        int progress = (int) ((totalBytesRead * 100) / contentLength);
        publishProgress(progress);
    }
    sink.flush();
    sink.close();
    source.close();
}

Answer 4

这是我在每次下载块后发布下载进度时使用 Okhttp + Okio 库的方式：

echo "data:"  . $event["time"]...

Answer 5

更好的解决方案是使用OkHttpClient：

OkHttpClient client = new OkHttpClient();

            Request request = new Request.Builder()
                    .url("http://publicobject.com/helloworld.txt")
                    .build();



            client.newCall(request).enqueue(new Callback() {
                @Override
                public void onFailure(Call call, IOException e) {
                    e.printStackTrace();
                }

                @Override
                public void onResponse(Call call, Response response) throws IOException {

                    if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

//                    Headers responseHeaders = response.headers();
//                    for (int i = 0; i < responseHeaders.size(); i++) {
//                        System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
//                    }
//                    System.out.println(response.body().string());

                    InputStream in = response.body().byteStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                    String result, line = reader.readLine();
                    result = line;
                    while((line = reader.readLine()) != null) {
                        result += line;
                    }
                    System.out.println(result);


                }
            });

Answer 6

基于kiddouk答案的Kotlin版本

 val request = Request.Builder().url(url).build()
 val response = OkHttpClient().newCall(request).execute()
 val downloadedFile = File(cacheDir, filename)
 val sink: BufferedSink = downloadedFile.sink().buffer()
 sink.writeAll(response.body!!.source())
 sink.close()

Answer 7

如果您尝试在最新的 Android 上将下载的字节写入 Shared Storage，您手上应该有 Uri 而不是 File 实例。以下是将 Uri 转换为 OutputStream 的方法：

fun Uri?.toOutputStream(context: Context)
        : OutputStream? {
    if (this == null) {
        return null
    }

    fun createAssetFileDescriptor() = try {
        context.contentResolver.openAssetFileDescriptor(this, "w")
    } catch (e: FileNotFoundException) {
        null
    }

    fun createParcelFileDescriptor() = try {
        context.contentResolver.openFileDescriptor(this, "w")
    } catch (e: FileNotFoundException) {
        null
    }

    /** scheme://<authority>/<path>/<id> */
    if (scheme.equals(ContentResolver.SCHEME_FILE)) {
        /** - If AssetFileDescriptor is used, it always writes 0B.
         * - (FileOutputStream | ParcelFileDescriptor.AutoCloseOutputStream) works both for app-specific + shared storage
         * - If throws "FileNotFoundException: open failed: EACCES (Permission denied)" on Android 10+, use android:requestLegacyExternalStorage="true" on manifest and turnOff/turnOn "write_external_storage" permission on phone settings. Better use Content Uri on Android 10+ */
        return try {
            FileOutputStream(toFile())
        } catch (e: Throwable) {
            null
        }

    } else if (scheme.equals(ContentResolver.SCHEME_ANDROID_RESOURCE)) {
        // i think you can't write to asset inside apk
        return null

    } else {
        // content URI (MediaStore)
        if (authority == android.provider.MediaStore.AUTHORITY) {
            return try {
                context.contentResolver.openOutputStream(this, "w")
            } catch (e: Throwable) {
                null
            }
        } else {
            // content URI (provider), not tested
            return try {
                val assetFileDescriptor = createAssetFileDescriptor()
                if (assetFileDescriptor != null) {
                    AssetFileDescriptor.AutoCloseOutputStream(assetFileDescriptor)
                } else {
                    val parcelFileDescriptor = createParcelFileDescriptor()
                    if (parcelFileDescriptor != null) {
                        ParcelFileDescriptor.AutoCloseOutputStream(parcelFileDescriptor)
                    } else {
                        null
                    }
                }
            } catch (e: Throwable) {
                null
            }
        }
    }
}

一旦你有了OutputStream，其余的答案与其他答案类似。有关 sink/source 和 emit/flush 的更多信息：

// create Request
val request = Request.Builder()
            .method("GET", null)
            .url(url)
            .build()

// API call function
fun apiCall(): Response? {
    return try {
        client.newCall(request).execute()
    } catch (error: Throwable) {
        null
    }
}

// execute API call
var response: Response? = apiCall()
// your retry logic if request failed (response==null)

// if failed, return
if (response == null || !response.isSuccessful) {
    return
}

// response.body
val body: ResponseBody? = response!!.body
if (body == null) {
    response.closeQuietly()
    return
}

// outputStream
val outputStream = destinationUri.toOutputStream(appContext)
if (outputStream == null) {
    response.closeQuietly() // calls body.close
    return
}
val bufferedSink: BufferedSink = outputStream!!.sink().buffer()
val outputBuffer: Buffer = bufferedSink.buffer

// inputStream
val bufferedSource = body!!.source()
val contentLength = body.contentLength()

// write
var totalBytesRead: Long = 0
var toBeFlushedBytesRead: Long = 0
val BUFFER_SIZE = 8 * 1024L // KB
val FLUSH_THRESHOLD = 200 * 1024L // KB
var bytesRead: Long = bufferedSource.read(outputBuffer, BUFFER_SIZE)
var lastProgress: Int = -1
while (bytesRead != -1L) {
    // emit/flush
    totalBytesRead += bytesRead
    toBeFlushedBytesRead += bytesRead
    bufferedSink.emitCompleteSegments()
    if (toBeFlushedBytesRead >= FLUSH_THRESHOLD) {
        toBeFlushedBytesRead = 0L
        bufferedSink.flush()
    }

    // write
    bytesRead = bufferedSource.read(outputBuffer, BUFFER_SIZE)

    // progress
    if (contentLength != -1L) {
        val progress = (totalBytesRead * 100 / contentLength).toInt()
        if (progress != lastProgress) {
            lastProgress = progress
            // update UI (using Flow/Observable/Callback)
        }
    }
}

bufferedSink.flush()

// close resources
outputStream.closeQuietly()
bufferedSink.closeQuietly()
bufferedSource.closeQuietly()
body.closeQuietly()

从OKHTTP下载二进制文件

修改

7 个答案: