Android网络交互判断网络连接的例子【源代码】

package com.laohuai.nettest; //Download by http://www.codefans.net import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.UnsupportedEncodingException; import java.net.URLEncoder; import java.util.Map; import org.apache.http.HttpResponse; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import android.app.Activity; import android.app.ProgressDialog; import android.content.Context; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.Bundle; import android.os.Handler; import android.widget.TextView; public class MainActivity extends Activity { private TextView resultView; private Handler handler; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); handler = new Handler(); resultView = (TextView) findViewById(R.id.resultTextView); ProgressDialog dialog = new ProgressDialog(getApplicationContext()); dialog.setMessage("数据获取中..."); new Thread(new Runnable() { public void run() { String s = null; if (isNetwordAvaliable(getApplicationContext())) { s = parseResponse(doConnectByGet("http://www.baidu.com", null)); } else { s = "没有可用网络连接"; } final String ss = s; handler.post(new Runnable() { public void run() { resultView.setText(ss); } }); } }).start(); } /** * 判断是否有可用的网络连接 * * @param context * @return */ private boolean isNetwordAvaliable(Context context) { boolean result = false; ConnectivityManager connectManager = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); if (connectManager == null) { result = false; } else { NetworkInfo[] netInfo = connectManager.getAllNetworkInfo(); for (NetworkInfo info : netInfo) { if (info.getState() == NetworkInfo.State.CONNECTED) { result = true; break; } } } return result; } /** * get方式访问一个url * * @param url * @param params */ private HttpResponse doConnectByGet(String url, Map<String, Object> params) { HttpResponse response = null; if (params != null) { StringBuffer sb = new StringBuffer(); for (Map.Entry<String, Object> entry : params.entrySet()) { try { sb.append(entry.getKey()) .append("=") .append(URLEncoder.encode(entry.getValue() .toString(), "UTF-8")).append("&"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } } sb.deleteCharAt(sb.length() - 1); url += url + "?" + sb.toString(); } HttpGet get = new HttpGet(url); try { response = new DefaultHttpClient().execute(get); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return response; } /** * 从HttpResponse中获取内容 * * @param response * @return */ private String parseResponse(HttpResponse response) { StringBuffer sb = new StringBuffer(); if (response.getStatusLine().getStatusCode() != 200) { sb.append("返回码不是200"); } else { BufferedReader reader = null; try { reader = new BufferedReader(new InputStreamReader(response .getEntity().getContent())); } catch (IllegalStateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } try { for (String s = reader.readLine(); s != null; s = reader .readLine()) { sb.append(s); } } catch (IOException e) { e.printStackTrace(); } try { reader.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); } }