DownloadXML.java

package me.qixingchen.mdbilibili.network;

import android.text.TextUtils;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;

import me.qixingchen.mdbilibili.app.BilibiliApplication;
import me.qixingchen.mdbilibili.utils.StorageUtil;
import rx.Observable;
import rx.Subscriber;
import rx.schedulers.Schedulers;

/**
 * Created by Yulan on 2015/6/12.
 * 下载弹幕 XML
 * 但是目前下载的 XML 连长度都不对。。
 * vsv:添加一点回调
 */
public class DownloadXML {

    private final static String TAG = DownloadXML.class.getSimpleName();

    public Observable<File> downloadXML(final String uriString) {
        return Observable.create(new Observable.OnSubscribe<File>() {
            @Override
            public void call(Subscriber<? super File> subscriber) {
                String errorMessage = "";
                URL url = null;
                String filename = null;
                BufferedInputStream inputStream = null;
                BufferedOutputStream outputStream = null;
                FileOutputStream fileStream = null;
                URLConnection connection = null;
                File file = null;
                final int DOWNLOAD_BUFFER_SIZE = 1024;
                try {
                    url = new URL(uriString);
                    connection = url.openConnection();
                    connection.setUseCaches(false);
                    if (StorageUtil.isExternalStorageAvailable()) {
                        filename = uriString.substring(uriString.lastIndexOf('=') + 1) + ".xml";
                        file = new File(BilibiliApplication.
                                getApplication().getExternalFilesDir("danmaku"), filename);
                        if (file.exists()) {
                            file.delete();
                        }
                        inputStream = new BufferedInputStream(connection.getInputStream());
                        fileStream = new FileOutputStream(file);
                        outputStream = new BufferedOutputStream(fileStream, DOWNLOAD_BUFFER_SIZE);
                        byte[] data = new byte[DOWNLOAD_BUFFER_SIZE];
                        int bytesRead = 0;
                        while ((bytesRead = inputStream.read(data, 0, data.length)) >= 0) {
                            outputStream.write(data, 0, bytesRead);
                        }
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                    errorMessage = e.getMessage();
                } finally {
                    try {
                        if (outputStream != null)
                            outputStream.close();
                        if (inputStream != null)
                            inputStream.close();
                        if (fileStream != null)
                            fileStream.close();
                    } catch (IOException ignored) {
                    }
                }
                if (TextUtils.isEmpty(errorMessage)) {
                    subscriber.onNext(file);
                } else {
                    subscriber.onError(new Exception(errorMessage));
                }

            }
        }).subscribeOn(Schedulers.io());
    }
}