下载和播放 mp3 文件到内部存储答案

【问题标题】：Downloading and Playing mp3 file into internal storage下载和播放 mp3 文件到内部存储
【发布时间】：2016-09-28 06:17:38
【问题描述】：

我们正在开发 android 应用程序，其中 mp3 文件应下载到后台服务的内部存储中。我们已经在intent service 中使用下面提到的代码 sn-p 实现了这一点，但是当我们尝试播放 mp3 时出现错误，例如播放器不支持此音频文件。如果有人对此问题有解决方案，请告知我。

代码片段：

    String urlPath = intent.getStringExtra(URL);
    String fileName = intent.getStringExtra(FILENAME);
    //  String fileName = Environment.getExternalStorageDirectory().toString() + "/trail.mp3";
    File output = new File(Environment.getExternalStorageDirectory(),
            fileName);

    File dir = new File(output.getAbsolutePath()
            + "/TRIALS/");

    dir.mkdirs();
    String path = dir + "/" +"trail" + ".mp3";
    File f = new File(path);


    if (f.exists()) {
        f.delete();
    }

    InputStream stream = null;
    FileOutputStream fos = null;
    try {

        URL url = new URL(urlPath);
        URLConnection conection = url.openConnection();
        conection.connect();
        // getting file length
        int lenghtOfFile = conection.getContentLength();
        //URL url = new URL(urlPath);
        InputStream input = new BufferedInputStream(url.openStream());

        stream = url.openConnection().getInputStream();
        InputStreamReader reader = new InputStreamReader(stream);
        fos = new FileOutputStream(f.getPath());

        byte data[] = new byte[lenghtOfFile];

        long total = 0;

        int times = -1;
        while ((times = reader.read()) != -1) {
            fos.write(times);

        }
        // Successful finished
        result = Activity.RESULT_OK;

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (fos != null) {
            try {
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    publishResults(output.getAbsolutePath(), result);
}

【问题讨论】：

标签： android file storage internal download

【解决方案1】：

1.检查urlPath是否正确。可以用资源管理器打开，检查.mp3是否开始下载。

2.将资源管理器获取的文件大小与通过代码下载的文件大小进行比较。

3.如果大小不同，则表示下载失败。尝试像这样修改您的代码：

    String urlPath = intent.getStringExtra(URL);
    String fileName = intent.getStringExtra(FILENAME);
    File output = new File(Environment.getExternalStorageDirectory(),
            fileName);
    File dir = new File(output.getAbsolutePath()
            + "/TRIALS/");
    dir.mkdirs();
    String path = dir + "/" +"trail" + ".mp3";
    File f = new File(path);

    if (f.exists()) {
        f.delete();
    }

    InputStream stream = null;
    FileOutputStream fos = null;
    try {

        URL url = new URL(urlPath);
        URLConnection urlcon = url.openConnection();
        stream = urlcon.getInputStream();

        InputStreamReader reader = new InputStreamReader(stream);
        fos = new FileOutputStream(f.getPath());

        int times = -1;
        while ((times = reader.read()) != -1) {
            fos.write(times);
        }

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        if (fos != null) {
            try {
                fos.flush();
                fos.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

我删除了一些无用的代码，并在fos.close()之前添加了fos.flush()。

【讨论】：