如何从网络读取Android中的文本文件？

Question

我是 Android 的新手。我需要从网页中读取文本文件并显示该文本文件。是否有可能直接在 Android 中查看文本文件？否则，如何在 Android Textview 中读取并显示文本文件？

- Krishna

Answer 1

使用DefaultHttpClient httpclient = new DefaultHttpClient();

HttpGet httppost = new HttpGet("http://www.urlOfThePageYouWantToRead.nl/text.txt");
HttpResponse response = httpclient.execute(httppost);
        HttpEntity ht = response.getEntity();

        BufferedHttpEntity buf = new BufferedHttpEntity(ht);

        InputStream is = buf.getContent();


        BufferedReader r = new BufferedReader(new InputStreamReader(is));

        StringBuilder total = new StringBuilder();
        String line;
        while ((line = r.readLine()) != null) {
            total.append(line + "\n");
        }

        TextView.setText(total);

希望这能帮到你！

- BadSkillz

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你为什么在使用+之后又使用了append呢？应该是append(line).append('\n')。 - Boldijar Paul

此内容已被弃用。 - Zoe stands with Ukraine

Answer 2

@BadSkillz 是对的，但在 API 的最后 9 个字符会出现错误:

    android.os.NetworkOnMainThreadException

因为在主线程中进行网络操作会使应用在任何请求的持续时间内变得无响应，所以您必须在另一个线程中进行网络操作。因此，您可以将此类添加到您的活动中：

private class GetStringFromUrl extends AsyncTask<String, Void, String> {

    ProgressDialog dialog ;

    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        // show progress dialog when downloading 
        dialog = ProgressDialog.show(MainActivity.this, null, "Downloading...");
    }

    @Override
    protected String doInBackground(String... params) {

        // @BadSkillz codes with same changes
        try {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(params[0]);
            HttpResponse response = httpClient.execute(httpGet);
            HttpEntity entity = response.getEntity();

            BufferedHttpEntity buf = new BufferedHttpEntity(entity);

            InputStream is = buf.getContent();

            BufferedReader r = new BufferedReader(new InputStreamReader(is));

            StringBuilder total = new StringBuilder();
            String line;
            while ((line = r.readLine()) != null) {
                total.append(line + "\n");
            }
            String result = total.toString();
            Log.i("Get URL", "Downloaded string: " + result);
            return result;
        } catch (Exception e) {
            Log.e("Get Url", "Error in downloading: " + e.toString());
        }
        return null;
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);

        // TODO change text view id for yourself
        TextView textView = (TextView) findViewById(R.id.textView1);

        // show result in textView
        if (result == null) {
            textView.setText("Error in downloading. Please try again.");
        } else {
            textView.setText(result);
        }

        // close progresses dialog
        dialog.dismiss();
    }
}

每次您需要使用时，请使用下面的行：

new GetStringFromUrl().execute("http://www.google.com/");

---

by helping @Leandros

- golkarm

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我不得不将“textView”作为类的成员，并通过构造函数进行链接，因为在AsyncTask中无法访问“findViewById”。除此之外，一切都很完美！ - Jon V

@Polarbear0106，有什么新消息吗？ - golkarm

Answer 3

这里发布的答案Android读取URL内容（结果中缺少内容）告诉你除了在textview中设置文本外，应该做什么。请按照格式要求严格翻译并返回结果。

- matsjoe