android - 我正在寻找一个关于将文本文件从 URL 保存到我的 Android 设备的简单教程

Question

我需要将一个文本文件从我的网站保存到我的 Android 设备。对于像我这样的新手，我似乎找不到能很好地解释这个过程的东西。有人可以指出我正确的方向吗？

Answer 1

将此添加到您的清单文件中..

 <uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

这个例子是在android中显示文本文件。它使用asynctask

 import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.net.URLConnection;
    import android.app.Activity;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.TextView;

    public class Display extends Activity implements
        OnClickListener {
    Button button;
    TextView outputText;

    public static final String URL =
        "URL";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        findViewsById();

        button.setOnClickListener(this);
    }

    private void findViewsById() {
        button = (Button) findViewById(R.id.button);
        outputText = (TextView) findViewById(R.id.outputTxt);
    }

    public void onClick(View view) {
        GetXMLTask task = new GetXMLTask();
        task.execute(new String[] { URL });
    }

    private class GetXMLTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {
            String output = null;
            for (String url : urls) {
                output = getOutputFromUrl(url);
            }
            return output;
        }

        private String getOutputFromUrl(String url) {
            StringBuffer output = new StringBuffer("");
            try {
                InputStream stream = getHttpConnection(url);
                BufferedReader buffer = new BufferedReader(
                        new InputStreamReader(stream));
                String s = "";
                while ((s = buffer.readLine()) != null)
                    output.append(s);
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            return output.toString();
        }

        // Makes HttpURLConnection and returns InputStream
        private InputStream getHttpConnection(String urlString)
                throws IOException {
            InputStream stream = null;
            URL url = new URL(urlString);
            URLConnection connection = url.openConnection();

            try {
                HttpURLConnection httpConnection = (HttpURLConnection) connection;
                httpConnection.setRequestMethod("GET");
                httpConnection.connect();

                if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                    stream = httpConnection.getInputStream();
                }
            } catch (Exception ex) {
                ex.printStackTrace();
            }
            return stream;
        }

        @Override
        protected void onPostExecute(String output) {
            outputText.setText(output);
        }
    }
    }