从 Android 中的 Internet 链接获取数据

Question

我正在制作一个带有 URL 的应用程序。 *.asp 扩展名，我们将所需的参数传递给它，并使用 POST 方法获取一些字符串结果。

关于如何实现这一点的任何建议？

更新：

实际上我有一个 .net 链接，它接受一些 POST 参数并给我一个结果。如何在 Android 中做到这一点？

Answer 1

HTTPResponse 应该可以解决问题：

DefaultHttpClient  httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://www.yoururl.com");

List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1); <!-- number should be the amount of parameters
nameValuePairs.add(new BasicNameValuePair("nameOfParameter", "parameter"));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

HttpResponse response = httpclient.execute(httppost);
HttpEntity ht = response.getEntity();

BufferedHttpEntity buf = new BufferedHttpEntity(ht);

InputStream is = buf.getContent();

现在您可以使用流，将数据写入字符串：

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

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

祝你好运！

Answer 2

尝试使用 AsynTask (http://developer.android.com/reference/android/os/AsyncTask.html)，切勿尝试在 onCreate 调用或任何其他 GUI 线程方法中执行任何耗时的任务。

Answer 3

以下是执行 POST 请求（包括参数）并在 Android 通知中显示收到的响应的 Android 活动的代码：

package org.anddev.android.webstuff;

import java.io.ByteArrayInputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.http.util.ByteArrayBuffer;

import android.app.Activity;
import android.app.NotificationManager;
import android.net.http.EventHandler;
import android.net.http.Headers;
import android.net.http.RequestQueue;
import android.net.http.SslCertificate;
import android.os.Bundle;
import android.util.Log;

public class HTTPPostExample extends Activity {

        // ===========================================================
        // Fields
        // ===========================================================

        private final String DEBUG_TAG = "httpPostExample";

        // ===========================================================
        // 'Constructors'
        // ===========================================================

        @Override
        public void onCreate(Bundle icicle) {
                super.onCreate(icicle);

                /* Create a new HTTP-RequestQueue. */
                android.net.http.RequestQueue rQueue = new RequestQueue(this);

                /* Prepare the Post-Text we are going to send. */
                String POSTText = null;
                try {
                        POSTText = "mydata=" + URLEncoder.encode("HELLO, ANDROID HTTPPostExample - by anddev.org", "UTF-8");
                } catch (UnsupportedEncodingException e) {
                        return;
                }
                /* And put the encoded bytes into an BAIS,
                 * where a function later can read bytes from. */
                byte[] POSTbytes = POSTText.getBytes();
                ByteArrayInputStream baos = new ByteArrayInputStream(POSTbytes);

                /* Create a header-hashmap */
                Map<String, String> headers = new HashMap<String, String>();
                /* and put the Default-Encoding for html-forms to it. */
                headers.put("Content-Type", "application/x-www-form-urlencoded");

                /* Create a new EventHandler defined above, to handle what gets returned. */
                MyEventHandler myEvH = new MyEventHandler(this);

                /* Now we call a php-file I prepared. It is exactly this:
                 * <?php
                 *              echo "POSTed data: '".$_POST['data']."'";
                 * ?>*/
                rQueue.queueRequest("http://www.anddev.org/postresponse.php", "POST",
                                headers, myEvH, baos, POSTbytes.length,false);

                /* Wait until the request is complete.*/
                rQueue.waitUntilComplete();
        }

        // ===========================================================
        // Worker Class
        // ===========================================================

        private class MyEventHandler implements EventHandler {
                private static final int RANDOM_ID = 0x1337;

                /** Will hold the data returned by the URLCall. */
                ByteArrayBuffer baf = new ByteArrayBuffer(20);

                /** Needed, as we want to show the results as Notifications. */
                private Activity myActivity;

                MyEventHandler(Activity activity) {
                        this.myActivity = activity;  }

                public void data(byte[] bytes, int len) {
                        baf.append(bytes, 0, len);  }

                public void endData() {
                        String text = new String(baf.toByteArray());
                        myShowNotificationAndLog("Data loaded: n" + text);  }

                public void status(int arg0, int arg1, int arg2, String s) {
                        myShowNotificationAndLog("status [" + s + "]");  }

                public void error(int i, String s) {
                        this.myShowNotificationAndLog("error [" + s + "]");  }

                public void handleSslErrorRequest(int arg0, String arg1, SslCertificate arg2) { }
                public void headers(Iterator arg0) { }
                public void headers(Headers arg0) { }

                private void myShowNotificationAndLog(String msg) {
                        /* Print msg to LogCat and show Notification. */
                        Log.d(DEBUG_TAG, msg);
                        NotificationManager nm = (NotificationManager) this.myActivity
                                        .getSystemService(Activity.NOTIFICATION_SERVICE);
                        nm.notifyWithText(RANDOM_ID, msg, NotificationManager.LENGTH_LONG, null);
                }
        }
}

plusminus的代码