通过接口返回数据下载文件的两种返回数据类型方法

/** 下载pdf文件 */    private String updateContentName;//文件名    private Call call;    private boolean isSuccess = true;//是否下载成功    File target = null;

protected void download(String downloadUrl) {        showLoading();

target = new File(Environment.getExternalStorageDirectory() + "/ZyHealthy/PDF", updateContentName);        if (!target.getParentFile().exists()) {            target.getParentFile().mkdirs();        }

OkHttpClient client = new OkHttpClient();        //构造请求        FormBody body = new FormBody.Builder()                .build();        final Request request1 = new Request.Builder()                .url(downloadUrl)                .post(body)                .build();

//包装Response使其支持进度回调        call = ProgressHelper.addProgressResponseListener(client, uiProgressResponseListener).newCall(request1);        call.enqueue(new Callback() {            @Override            public void onFailure(Call call, IOException e) {                DesityUtil.showToast("下载失败，请尝试重新下载"+e);                closeLoading();            }

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

//                //方案一 String型的byte数组//                int n = 1024;//                String bodyStr = response.body().string();//                try {//                    String decodedString = new String(Base64Utils.decode(bodyStr));//                    byte[] bytes = gson.fromJson(decodedString, new TypeToken<byte []>(){}.getType());//                    FileOutputStream fos  = new FileOutputStream(target, true);//                    int length = bytes.length;//                    int start = 0;//                    while (length > start+n) {//                        fos.write(bytes, start, n);//                        start = start+n;//                    }//                    if (length != start+n) {//                        n = length-start;//                        fos.write(bytes, start, n);//                    }//                    fos.flush();//                    fos.close();//                } catch (Exception e) {//                    e.printStackTrace();//                }

//方案二 io流                InputStream is = response.body().byteStream();                FileOutputStream fos = new FileOutputStream(target, true);                byte[] buffer = new byte[2048];//缓冲数组2kB                int len;                while ((len = is.read(buffer)) != -1) {                    fos.write(buffer, 0, len);                }                fos.flush();                is.close();                fos.close();

closeLoading();

if (target.exists()) {                    dialogFragment = new PromptDialogFragment();                    dialogFragment                            .setTitle(getResources().getString(R.string.tjbb_exportPDF) + "  /ZyHealthy/PDF/" + updateContentName)                            .setMissVisibility(View.GONE)                            .setSureOnClickListener(new NoDoubleClickListener() {

@Override                                protected void onNoDoubleClick(View v) {                                    dialogFragment.dismiss();                                }                            });                    dialogFragment.show(getFragmentManager(), "FullScreenDownPDFFragment");                } else {                    DesityUtil.showToast("下载失败，请尝试重新下载");                }            }        });    }

//这个是ui线程回调，可直接操作UI    PromptDialogFragment dialogFragment;    UIProgressListener uiProgressResponseListener = new UIProgressListener() {        @Override        public void onUIProgress(long bytesRead, long contentLength, boolean done) {            isSuccess = done;            NumberFormat formatter = new DecimalFormat("00.#");//            String format = formatter.format(Float.valueOf(bytesRead) / contentLength * 100);            // 下载完成 弹框提示            if (100 <= (Float.valueOf(bytesRead) / contentLength * 100)) {//                DesityUtil.showToast("下载完成");            }        }

@Override        public void onUIStart(long bytesRead, long contentLength, boolean done) {            super.onUIStart(bytesRead, contentLength, done);        }

@Override        public void onUIFinish(long bytesRead, long contentLength, boolean done) {            super.onUIFinish(bytesRead, contentLength, done);            isSuccess = done;        }    };

public void showLoading() {        if (loadingFragment != null)            loadingFragment.show(getFragmentManager(), "loading");    }

public void closeLoading() {        if (loadingFragment != null)            loadingFragment.dismiss();    }