我在运行RssReader的Android项目时出错。

代码:

URL url = new URL(urlToRssFeed);
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
XMLReader xmlreader = parser.getXMLReader();
RssHandler theRSSHandler = new RssHandler();
xmlreader.setContentHandler(theRSSHandler);
InputSource is = new InputSource(url.openStream());
xmlreader.parse(is);
return theRSSHandler.getFeed();

它显示以下错误:

android.os.NetworkOnMainThreadException

如何解决此问题?


当前回答

截至2018年,我建议在Kotlin中使用RxJava进行网络获取。下面是一个简单的例子。

Single.fromCallable {
        // Your Network Fetching Code
        Network.fetchHttp(url) 
    }
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe {
        // What you need to do with your result on the view 
        result -> view.updateScreen(result) 
    }

其他回答

使用以下代码禁用严格模式:

if (android.os.Build.VERSION.SDK_INT > 9) {
    StrictMode.ThreadPolicy policy = 
        new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
}

不建议使用AsyncTask接口。

两种方法的完整代码

在活动中使用此项

    btnsub.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new Thread(new Runnable() {

                @Override
                public void run() {
                    // TODO Auto-generated method stub

                    //Initialize soap request + add parameters
                    SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME1);

                    //Use this to add parameters
                    request.addProperty("pincode", txtpincode.getText().toString());
                    request.addProperty("bg", bloodgroup.getSelectedItem().toString());

                    //Declare the version of the SOAP request
                    SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);

                    envelope.setOutputSoapObject(request);
                    envelope.dotNet = true;

                    try {
                        HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

                        //this is the actual part that will call the webservice
                        androidHttpTransport.call(SOAP_ACTION1, envelope);

                        // Get the SoapResult from the envelope body.
                        SoapObject result = (SoapObject) envelope.getResponse();
                        Log.e("result data", "data" + result);
                        SoapObject root = (SoapObject) result.getProperty(0);
                        // SoapObject s_deals = (SoapObject) root.getProperty(0);
                        // SoapObject s_deals_1 = (SoapObject) s_deals.getProperty(0);
                        //

                        System.out.println("********Count : " + root.getPropertyCount());

                        value = new ArrayList<Detailinfo>();

                        for (int i = 0; i < root.getPropertyCount(); i++) {
                            SoapObject s_deals = (SoapObject) root.getProperty(i);
                            Detailinfo info = new Detailinfo();

                            info.setFirstName(s_deals.getProperty("Firstname").toString());
                            info.setLastName(s_deals.getProperty("Lastname").toString());
                            info.setDOB(s_deals.getProperty("DOB").toString());
                            info.setGender(s_deals.getProperty("Gender").toString());
                            info.setAddress(s_deals.getProperty("Address").toString());
                            info.setCity(s_deals.getProperty("City").toString());
                            info.setState(s_deals.getProperty("State").toString());
                            info.setPinecode(s_deals.getProperty("Pinecode").toString());
                            info.setMobile(s_deals.getProperty("Mobile").toString());
                            info.setEmail(s_deals.getProperty("Email").toString());
                            info.setBloodgroup(s_deals.getProperty("Bloodgroup").toString());
                            info.setAdddate(s_deals.getProperty("Adddate").toString());
                            info.setWaight(s_deals.getProperty("waight").toString());
                            value.add(info);
                        }

                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    Intent intent = new Intent(getApplicationContext(), ComposeMail.class);
                    //intent.putParcelableArrayListExtra("valuesList", value);

                    startActivity(intent);
                }
            }).start();
        }
    });

这个问题有两种解决方案。

不要在主UI线程中使用网络调用。为此使用异步任务。在setContentView(R.layout.activity_main)之后,将以下代码写入MainActivity文件:如果(android.os.Build.VERSION.SDK_INT>9){StrictMode.ThreadPolicy policy=new StrictMode.SthreadPolicy.Builder().permitAll().build();StrictMode.setThreadPolicy(策略);}

以及下面的import语句到Java文件中。

import android.os.StrictMode;

您不应该在主线程(UI线程)上执行任何耗时的任务,如任何网络操作、文件I/O或SQLite数据库操作。因此,对于这种操作,您应该创建一个工作线程,但问题是您不能直接从工作线程执行任何与UI相关的操作。为此,您必须使用Handler并传递消息。

为了简化所有这些事情,Android提供了各种方式,如AsyncTask、AsyncTaskLoader、CursorLoader或IntentService。因此,您可以根据您的要求使用任何这些。

我使用新线程解决了这个问题。

Thread thread = new Thread(new Runnable() {

    @Override
    public void run() {
        try  {
            //Your code goes here
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
});

thread.start();