Question

在我的应用程序中，我有一个方法，它接受一个地址字符串并获取有关它的信息，并使用Google Geocode将其转换为JSONObject。方法如下：

public static JSONObject getLocationInfo(String address) {

    StringBuilder stringBuilder = new StringBuilder();

    try {
        address = address.replaceAll(" ","%20");    

        HttpPost httppost = new HttpPost("http://maps.google.com/maps/api/geocode/json?address=" + address + "&sensor=false");
        HttpClient client = new DefaultHttpClient();
        HttpResponse response;
        stringBuilder = new StringBuilder();


        response = client.execute(httppost);
        HttpEntity entity = response.getEntity();
        InputStream stream = entity.getContent();
        int b;
        while ((b = stream.read()) != -1) {
            stringBuilder.append((char) b);
        }
    } catch (ClientProtocolException e) {
    } catch (IOException e) {
    }

    JSONObject jsonObject = new JSONObject();
    try {
        jsonObject = new JSONObject(stringBuilder.toString());
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    return jsonObject;
}

当我在设备上通过Eclipse运行应用程序时，这很好用。但是，当我制作APK并将其安装在设备上时，应用程序会在上面的代码中崩溃。我的日志cat输出如下：

 04-14 21:43:19.677: E/AndroidRuntime(21560): FATAL EXCEPTION: main
 04-14 21:43:19.677: E/AndroidRuntime(21560): Process: com.example.carpool, PID: 21560
 04-14 21:43:19.677: E/AndroidRuntime(21560): android.os.NetworkOnMainThreadException
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at java.net.InetAddress.getAllByName(InetAddress.java:214)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at com.example.carpool.Book.getLocationInfo(Book.java:421)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at com.example.carpool.Book$8.onItemClick(Book.java:236)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AutoCompleteTextView.performCompletion(AutoCompleteTextView.java:902)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AutoCompleteTextView.access$500(AutoCompleteTextView.java:91)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AutoCompleteTextView$DropDownItemClickListener.onItemClick(AutoCompleteTextView.java:1192)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AdapterView.performItemClick(AdapterView.java:299)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.widget.AbsListView$3.run(AbsListView.java:3638)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.os.Handler.handleCallback(Handler.java:733)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.os.Handler.dispatchMessage(Handler.java:95)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.os.Looper.loop(Looper.java:136)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at android.app.ActivityThread.main(ActivityThread.java:5017)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at java.lang.reflect.Method.invokeNative(Native Method)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at java.lang.reflect.Method.invoke(Method.java:515)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
 04-14 21:43:19.677: E/AndroidRuntime(21560):   at dalvik.system.NativeStart.main(Native Method)

崩溃的确切行是response = client.execute(httppost);行。我不知道为什么会这样，以及如何纠正？

Answer 1

您正在从Main Thread访问网络。您只能在后台Thread

中进行网络操作

像这样使用AsyncTask

 new AsyncTask<URL, Integer, Long>(){
            @Override
            protected Long doInBackground(URL... params) {
                try {

                    // call you method here

                } catch (Exception ex) {
                    // handle the exception here
                }
                return null;
            }
        }.execute();

Answer 2

android.os.NetworkOnMainThreadException表示您正在主（ui）线程上执行网络。你不能在主线程上执行网络操作.android不允许这样做。这就是崩溃的原因。在asyntask中移动你的http请求，所以它将在单独的线程中运行，你的应用程序不会崩溃。

在调试模式下应用程序工作正常，但apk崩溃

2 个答案: