我想从异步任务中恢复数据而不是直接使用阅读器上的get方法，因为它会阻止UI。所以我已经实现了一个简单的接口，它提供了一个回调函数，wicth传递来自Url的数据。但是当我启动应用程序时，它会崩溃。这是我的代码：
MAIN ACTIVITY:
public class MainActivity extends ActionBarActivity implements OnTaskComplete{
String result = null;
@Override
public void callBackFunction(String s) {
result = s;
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String handler = null;
try {
URL address = new URL("http://www.youth-stories.com/api/focusOnAll.php");
MyAsync reader = new MyAsync(this, this, handler);
reader.execute(address);
} catch (MalformedURLException e) {
e.printStackTrace();
}
Toast.makeText(this, handler, Toast.LENGTH_LONG).show();
}
}
ASYNC TASK:
public class MyAsync extends AsyncTask<URL, Void, String> {
ProgressDialog dialog = null;
Context context = null;
private OnTaskComplete mlistener;
private String myString;
public MyAsync(Context context, OnTaskComplete mlistener, String contents) {
this.mlistener = mlistener;
myString = contents;
dialog = new ProgressDialog(context);
}
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog.setMessage("Loading...");
dialog.show();
}
String result = null;
@Override
protected String doInBackground(URL... params) {
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(
params[0].openStream()
)
);
result = reader.readLine();
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
mlistener.callBackFunction(s);
myString = s;
dialog.dismiss();
}
}
INTERFACE:
public interface OnTaskComplete {
public void callBackFunction(String s);
}
03-09 09:21:04.975 24825-24853/com.example.callbackdata D/OpenGLRenderer﹕ Render dirty regions requested: true
03-09 09:21:04.981 24825-24825/com.example.callbackdata D/Atlas﹕ Validating map...
03-09 09:21:05.004 24825-24858/com.example.callbackdata E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
Process: com.example.callbackdata, PID: 24825
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.SecurityException: Permission denied (missing INTERNET permission?)
at java.net.InetAddress.lookupHostByName(InetAddress.java:451)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190)
at java.net.URL.openStream(URL.java:470)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:44)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:12)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: android.system.GaiException: android_getaddrinfo failed: EAI_NODATA (No address associated with hostname)
at libcore.io.Posix.android_getaddrinfo(Native Method)
at libcore.io.ForwardingOs.android_getaddrinfo(ForwardingOs.java:55)
at java.net.InetAddress.lookupHostByName(InetAddress.java:438)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190)
at java.net.URL.openStream(URL.java:470)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:44)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:12)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: android.system.ErrnoException: android_getaddrinfo failed: EACCES (Permission denied)
at libcore.io.Posix.android_getaddrinfo(Native Method)
at libcore.io.ForwardingOs.android_getaddrinfo(ForwardingOs.java:55)
at java.net.InetAddress.lookupHostByName(InetAddress.java:438)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190)
at java.net.URL.openStream(URL.java:470)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:44)
at com.example.callbackdata.MyAsync.doInBackground(MyAsync.java:12)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
03-09 09:23:57.001 25225-25225/com.example.callbackdata I/art﹕ Late-enabling -Xcheck:jni
03-09 09:23:57.174 25225-25260/com.example.callbackdata D/OpenGLRenderer﹕ Render dirty regions requested: true
03-09 09:23:57.179 25225-25225/com.example.callbackdata D/Atlas﹕ Validating map...
03-09 09:23:57.224 25225-25260/com.example.callbackdata I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: QUALCOMM Build: 10/24/14, 167c270, I68fa98814b
03-09 09:23:57.225 25225-25260/com.example.callbackdata I/OpenGLRenderer﹕ Initialized EGL, version 1.4
03-09 09:23:57.237 25225-25260/com.example.callbackdata D/OpenGLRenderer﹕ Enabling debug mode 0
03-09 09:25:29.852 25621-25639/com.example.callbackdata D/OpenGLRenderer﹕ Render dirty regions requested: true
03-09 09:25:29.862 25621-25621/com.example.callbackdata D/Atlas﹕ Validating map...
03-09 09:25:29.927 25621-25639/com.example.callbackdata I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:410>: QUALCOMM Build: 10/24/14, 167c270, I68fa98814b
03-09 09:25:29.927 25621-25639/com.example.callbackdata I/OpenGLRenderer﹕ Initialized EGL, version 1.4
03-09 09:25:29.940 25621-25639/com.example.callbackdata D/OpenGLRenderer﹕ Enabling debug mode 0
答案 0 :(得分：0)
Caused by: java.lang.SecurityException: Permission denied (missing INTERNET permission?)
您需要在清单中添加此行：
<uses-permission android:name="android.permission.INTERNET" />
编辑： 您似乎已经完成了它，是否可以将您的清单文件添加到您的帖子中？