問題描述

各位 剛接觸android，請教個問題，android使用httpclient獲取服務器端的json數據總是失敗，但是同樣的代碼用java工程來運行就可以獲取結果，這個是為什么？

代碼很簡短： 但是總是連接失敗

protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); String content = ''; TextView tv = (TextView) findViewById(R.id.showWiki); String url = 'http://www.nowamagic.net/academy/android/'; HttpClient httpclient = new DefaultHttpClient(); HttpGet httpget = new HttpGet(url); ResponseHandler<String> responseHandler = new BasicResponseHandler(); try {content = httpclient.execute(httpget, responseHandler);Toast.makeText(getApplicationContext(), '連接成功！', Toast.LENGTH_SHORT).show();tv.setText(content); } catch (Exception e) {// TODO: handle exceptionToast.makeText(getApplicationContext(), '連接失敗！', Toast.LENGTH_SHORT).show();e.printStackTrace(); } httpclient.getConnectionManager().shutdown();}

<uses-permission android:name='android.permission.INTERNET'></uses-permission> 這句話我也加了

問題解答

private void httpRequest() {new Thread() { @Override public void run() {super.run();HttpClient httpclient = new DefaultHttpClient();HttpGet httpget = new HttpGet(url);ResponseHandler<String> responseHandler = new BasicResponseHandler();try { content = httpclient.execute(httpget, responseHandler); Toast.makeText(getApplicationContext(), '連接成功！', Toast.LENGTH_SHORT).show(); //更新UI，子線程不能更新UI runOnUiThread(new Runnable() {@Overridepublic void run() { tv.setText(content);} });} catch (Exception e) { // TODO: handle exception Toast.makeText(getApplicationContext(), '連接失敗！', Toast.LENGTH_SHORT).show(); e.printStackTrace();}httpclient.getConnectionManager().shutdown(); }}.start(); }回答2：

網絡請求不要放到主線程中進行請求，可以用Thread在主線程外進行請求。