Java 尝试执行HTTP Post时获取NetworkOnMainThread错误

您好，我正在尝试向基于PHP的服务器发送一个简单的HTTP post，该服务器接受post数据$\u post['username']

public void sendMessage(View view){

    String result = "";

    Intent intent = new Intent(this, DisplayMessageActivity.class);
    EditText editText = (EditText) findViewById(R.id.edit_message);
    String message = editText.getText().toString();
    intent.putExtra(EXTRA_MESSAGE, message);

    Toast.makeText(
            getApplicationContext(),
            "Attempting to open second activity",
            Toast.LENGTH_LONG
    ).show();

    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("username","ghost"));

    InputStream is = null;

    // ATTEMPT HTTP POST
    try{
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://example.com/getuserbyuname");
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
    }catch(Exception e){
            Log.e("log_tag", "Error in http connection (Reason: " + e.toString() + " )");
    }

我在android.os.NetworkOnMainThread上遇到问题。我知道这是因为我的例程试图从主UI线程中执行与网络相关的操作

我确实试过：

public class AccountConnector extends AsyncTask <String, Integer, Long>{

@Override
protected Long doInBackground(String... params)
{
    ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
    nameValuePairs.add(new BasicNameValuePair("username","bond"));

    InputStream is = null;

    // ATTEMPT HTTP POST
    try{
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://example.com/getuserbyuname");
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();
    }catch(Exception e){
            Log.e("log_tag", "Error in http connection (Reason: " + e.toString() + " )");
    }
    return null;
}

公共类AccountConnector扩展异步任务{
@凌驾
受保护的长doInBackground（字符串…参数）
{
ArrayList nameValuePairs=新的ArrayList（）；
添加（新的BasicNameValuePair（“用户名”、“债券”）；
InputStream=null；
//尝试HTTP POST
试一试{
HttpClient HttpClient=新的DefaultHttpClient（）；
HttpPost HttpPost=新的HttpPost（“http://example.com/getuserbyuname");
setEntity（新的UrlEncodedFormEntity（nameValuePairs））；
HttpResponse response=httpclient.execute（httppost）；
HttpEntity=response.getEntity（）；
is=entity.getContent（）；
}捕获（例外e）{
Log.e（“Log_标记”，“http连接错误（原因：“+e.toString（）+”）”）；
}
返回null；
}

…其余代码被省略

谁能给我指一下正确的方向吗？

加上这个

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
             .permitAll().build();
StrictMode.setThreadPolicy(policy);

把这个放在清单文件里

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

解决此问题的正确方法是使用网络访问

处理此问题的惰性方法是将检查转到：

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

出于好奇：为什么您希望网络I/O在主线程中运行？使用AsynchTask（）示例：@mthmulders基本上检查数据库中是否存在被查询的uname。@KaranMavadhiya正在研究这个问题。谢谢。我确实研究了您的参考资料。不过，引用文章中的内容是这样的“StrictMode只能在开发过程中使用，而不能在实时应用程序中使用。”
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);