Question

我写了一个简单的方法来使用apache HTTPClient获取一些字符串数据，但是当我在手机上运行它时会返回一个空白屏幕;我正在尝试在textarea中显示数据。清单具有互联网许可。任何人都可以指出我可能做错了什么吗？

public String getInternetData() throws Exception
{
    BufferedReader in = null;
    String data = null;
    try
    {
        HttpClient client = new DefaultHttpClient();
        URI website = new URI("http://www.yahoo.com");
        HttpGet request = new HttpGet();
        request.setURI(website);
        HttpResponse response = client.execute(request);
        in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
        StringBuffer sb = new StringBuffer("");
        String l = "";
        String nl = System.getProperty("line.separator");
        while((l=in.readLine())!=null){
            sb.append(l+nl);
        }
        in.close();
        data = sb.toString();
        return data;
    }finally{
        if(in !=null){
            try{
                in.close();
                return data;
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

为了完整性，我添加了用于查看数据的代码。

public class MainActivity extends Activity {

TextView httpStuff;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    httpStuff = (TextView) findViewById(R.id.tvHttp);
    GetMethodEx test = new GetMethodEx();
    String returned;
    try {
        returned = test.getInternetData();
        httpStuff.setText(returned);

    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
}

Answer 1

你可能正在获取UI线程错误的网络，并且因为它在try catch中，应用程序没有崩溃

你应该只在后台线程中调用网络操作，或者是非常适合的那个

的AsyncTasks

您的HTTP客户端和请求数据没有任何问题，问题确实在于您的onCreate方法

尝试以这种方式重写

   public class MainActivity extends Activity {

TextView httpStuff;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    httpStuff = (TextView) findViewById(R.id.tvHttp);


    AsyncTask<Void,Void,String>getDataTask = new AsyncTask<Void,Void,String>(){
      @Override
      protected String doInBackground(Void... params){
        GetMethodEx test = new GetMethodEx();
        String returned = test.getInternalData();
        return returned;

       }
      @Override
      protected void onPostExecute(String returned){
      httpStuff.setText(returned);
}

}



}
      getDataTask.execute();
}

Android应用程序上的HTTP客户端返回空白屏幕

1 个答案: