Android HTTP 获取

Question

我查看了一些论坛帖子，但找不到我的问题的答案。我正在尝试从 php 文件中获取响应。 php 文件正在运行。问题是 Android 应用程序不会执行我的请求。以下是我的代码的两个示例以及我在 TextView 中获得的结果:

public void changText(View view) {
    TextView textv = (TextView)findViewById(R.id.textview1);
    textv.setText("Text Has Been Changed");
    BufferedReader in = null;
    String data = null;

    try{
           HttpClient httpclient = new DefaultHttpClient();

           HttpGet request = new HttpGet();
           URI website = new URI("http://alanhardin.comyr.com/matt24/matt28.php");
           request.setURI(website);
           HttpResponse response = httpclient.execute(request);
           in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

           textv.append(" Connected ");
       }catch(Exception e){
           Log.e("log_tag", "Error in http connection "+e.toString());
       }


   }

TextView 显示:Text Has Been Changed

    public void changText(View view) {
    TextView textv = (TextView)findViewById(R.id.textview1);
    textv.setText("Text Has Been Changed");
    BufferedReader in = null;
    String data = null;

    try{
           HttpClient httpclient = new DefaultHttpClient();

           HttpGet request = new HttpGet();
           URI website = new URI("http://alanhardin.comyr.com/matt24/matt28.php");
           request.setURI(website);
           //HttpResponse response = httpclient.execute(request);
           //in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

           textv.append(" Connected ");
       }catch(Exception e){
           Log.e("log_tag", "Error in http connection "+e.toString());
       }


   }

TextView 显示:Text Has Been Changed Connected

在这份 list 中我有:

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

在错误日志中，我得到以下信息:http 连接错误 android.os.NetworkOnMainThreadException

如有任何帮助，我们将不胜感激。

Answer 1

Android 可能会很好地执行您的请求。您似乎只是忽略了服务器返回的数据。你可以这样做，例如:

public void changText(View view) {
    TextView textv = (TextView)findViewById(R.id.textview1);
    textv.setText("Text Has Been Changed");
    BufferedReader in = null;
    String data = null;

    try{
           HttpClient httpclient = new DefaultHttpClient();

           HttpGet request = new HttpGet();
           URI website = new URI("http://alanhardin.comyr.com/matt24/matt28.php");
           request.setURI(website);
           HttpResponse response = httpclient.execute(request);
           in = new BufferedReader(new InputStreamReader(
                   response.getEntity().getContent()));

           // NEW CODE
           String line = in.readLine();
           textv.append(" First line: " + line);
           // END OF NEW CODE

           textv.append(" Connected ");
       }catch(Exception e){
           Log.e("log_tag", "Error in http connection "+e.toString());
       }
}

看起来你的服务器正在返回一个 JSON 对象，所以你可能想要做一些更智能的事情，比如读取整个响应，解析它(使用 new JSONArray(response))，然后提取相关字段，但上面的代码至少会验证 Android 是否正在执行您的查询。

编辑:从您报告的异常来看，您似乎是在主 UI 线程上运行代码。从 API 11 开始，这是被禁止的(并且在此之前是不受欢迎的)。有几篇文章介绍如何解决此问题。请参阅指南主题 Painless threading以及教程here和 here .另见 this thread获取更多信息。