我有一个从本地主机加载文本文件的代码，我正在使用xampp，我将文件放在htdocs下的xampp文件夹中。这是我的代码：
public class MainActivity extends Activity {
TextView httpStuff;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
httpStuff = (TextView)findViewById(R.id.tvHttp);
try {
URL url = new URL("http://10.0.2.2/name.txt");
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String str = in.readLine();
in.close();
httpStuff.setText(str);
} catch (MalformedURLException e) {
e.printStackTrace();
}catch (IOException e) {
// TODO: handle exception
}
}}
我得到了这个错误。我不知道怎么了我还在androidmanifest.xml文件中添加了Internet权限。
10-24 17:17:45.024: E/AndroidRuntime(7544): FATAL EXCEPTION: main
10-24 17:17:45.024: E/AndroidRuntime(7544): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.name.in.a.textfile/com.example.name.in.a.textfile.MainActivity}: android.os.NetworkOnMainThreadException
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread.access$600(ActivityThread.java:130)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.os.Handler.dispatchMessage(Handler.java:99)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.os.Looper.loop(Looper.java:137)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread.main(ActivityThread.java:4745)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.lang.reflect.Method.invokeNative(Native Method)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.lang.reflect.Method.invoke(Method.java:511)
10-24 17:17:45.024: E/AndroidRuntime(7544): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-24 17:17:45.024: E/AndroidRuntime(7544): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-24 17:17:45.024: E/AndroidRuntime(7544): at dalvik.system.NativeStart.main(Native Method)
10-24 17:17:45.024: E/AndroidRuntime(7544): Caused by: android.os.NetworkOnMainThreadException
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.io.IoBridge.connect(IoBridge.java:112)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.net.Socket.connect(Socket.java:842)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:76)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:341)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:315)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpEngine.connect(HttpEngine.java:310)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
10-24 17:17:45.024: E/AndroidRuntime(7544): at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
10-24 17:17:45.024: E/AndroidRuntime(7544): at java.net.URL.openStream(URL.java:462)
10-24 17:17:45.024: E/AndroidRuntime(7544): at com.example.name.in.a.textfile.MainActivity.onCreate(MainActivity.java:27)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.Activity.performCreate(Activity.java:5008)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-24 17:17:45.024: E/AndroidRuntime(7544): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
10-24 17:17:45.024: E/AndroidRuntime(7544): ... 11 more
最佳答案
您的问题显示在此行中android.os.NetworkOnMainThreadException 10-24 17:07:44.745: E/AndroidRuntime(7143)
在android中，您无法在主线程中执行网络操作，因为它可能会阻止UI更新超过5秒钟，从而导致应用程序无法响应。
您应该做这样的事情（未经测试）try块应为：
Thread t = new Thread(new Runnable() {
@Override
public void run() {
URL url = new URL("http://10.0.2.2/name.txt");
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String str = in.readLine();
in.close();
runOnUIThread(new Runnable() {
@Override
public void run() {
httpStuff.setText(str);
}
});
});
t.start();
这样，您可以在其他线程上执行联网，但是由于联网完成后需要更新UI，因此需要使用
runOnUIThread，因为在UI线程上可以更新UI组件。另一个可能更好的选择是
AsyncTask您可以将网络任务放在其
doInBackground方法中，并在onPostExecute方法中更新UI，这样就不必弄乱线程了。基本上AsyncTask会执行我上面描述的操作。您应该考虑一下这一点，因为所有联网都应在与UI不同的线程中完成，并且AsyncTask是一个很好的选择。关于android - ANDROID-从本地主机读取文件(错误)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/13045053/