我正在尝试定期运行后台服务。我使用IntentService作为后台服务以及处理程序。但是当我尝试使用Toast确认服务正在定期运行时，logcat会在死线程上向Handler发送消息。此外，当我尝试在处理程序中使用getMainLooper时，应用程序不会运行。 Logcat给出＆＃34; NetworkOnMainThreadException＆＃34;我该怎么办？
Sep 29, 2015 8:20:30 AM org.apache.catalina.core.AprLifecycleListener init
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre1.8.0_31\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Program Files/Java/jre1.8.0_31/bin/client;C:/Program Files/Java/jre1.8.0_31/bin;C:/Program Files/Java/jre1.8.0_31/lib/i386;C:\ProgramData\Oracle\Java\javapath;C:\Python34\;C:\Python34\Scripts;C:\Program Files\Common Files\ArchestrA\;\Program Files\Common Files\ArchestrA\;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Inductive Automation\Ignition;C:\Program Files\Java32\bin;C:\Program Files\Windows Live\Shared;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Program Files\Wonderware\InTouch\;C:\Program Files\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\;C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;C:\Program Files\Wonderware\InBatch\bin;C:\Program Files\Common Files\Invensys\;C:\MinGW\bin;C:\MINGW\msys;c:\OpenOPC\bin;C:\xampp\php;c:\OpenOPC\bin;c:\OpenOPC\bin;C:\Program Files\TortoiseSVN\bin;c:\Program Files\Microsoft SQL Server\110\Tools\Binn\ManagementStudio\;c:\Program Files\Microsoft SQL Server\110\DTS\Binn\;C:\Program Files\TortoiseGit\bin;C:\Program Files\eclipse;;.
Sep 29, 2015 8:20:30 AM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:Service' did not find a matching property.
Sep 29, 2015 8:20:31 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Sep 29, 2015 8:20:31 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-bio-8009"]
Sep 29, 2015 8:20:31 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1261 ms
Sep 29, 2015 8:20:31 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Sep 29, 2015 8:20:31 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.56
Sep 29, 2015 8:20:33 AM org.apache.catalina.util.SessionIdGenerator createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [222] milliseconds.
Sep 29, 2015 8:20:35 AM org.apache.catalina.core.ContainerBase startInternal
SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/Service]]
at java.util.concurrent.FutureTask.report(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:816)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/BrimJava]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 6 more
Caused by: java.lang.NoClassDefFoundError: com/sun/istack/localization/Localizable
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.sun.xml.ws.transport.http.servlet.WSServletContainerInitializer.onStartup(WSServletContainerInitializer.java:64)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5481)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
Caused by: java.lang.ClassNotFoundException: com.sun.istack.localization.Localizable
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 31 more
Sep 29, 2015 8:20:35 AM org.apache.catalina.core.ContainerBase startInternal
SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at java.util.concurrent.FutureTask.report(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:816)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 6 more
Sep 29, 2015 8:20:35 AM org.apache.catalina.startup.Catalina start
SEVERE: The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 11 more
Sep 29, 2015 8:20:35 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["http-bio-8080"]
Sep 29, 2015 8:20:35 AM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["ajp-bio-8009"]
Sep 29, 2015 8:20:35 AM org.apache.catalina.core.StandardService stopInternal
INFO: Stopping service Catalina
Sep 29, 2015 8:20:35 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["http-bio-8080"]
Sep 29, 2015 8:20:35 AM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["ajp-bio-8009"]
答案 0 :(得分：0)
这是由于Android框架中AsyncTask中的错误。
它期望在主线程上初始化它，但是这不能保证，因为它将在导致类运行其静态初始化器的任何线程上初始化。我重现了Handler引用工作线程的问题。
试试这段代码：
public class Background extends IntentService
{
Handler mMainThreadHandler = null;
public Background() {
super("This is the simple background classes");
mMainThreadHandler = new Handler();
}
@Override
protected void onHandleIntent(Intent intent)
{
mMainThreadHandler.post(new Runnable()
{
@Override
public void run()
{
Toast.makeText(getApplicationContext(), "Finally can I do it", Toast.LENGTH_SHORT).show();
Log.v("message","This is simple background services");
Db db =new Db(Background.this,"simple",null,4);
Cursor c= db.getData();
if( c.moveToFirst())
{
List<Map<String, String>> contacts = new ArrayList<Map<String, String>>();
do
{
String num,dater;
int integer;
integer=c.getInt (c.getColumnIndex(Base.Identifier));
num = c.getString(c.getColumnIndex(Base.CONTACTS));
dater =c.getString(c.getColumnIndex(Base.DATE));
Map<String, String> contact = new HashMap<String, String>();
contact.put("date", dater);
contact.put("contact", num);
contact.put("id",String.valueOf(integer));
contacts.add(contact);
}
while (c.moveToNext());
try
{
new Thread(new Runnable() {
@Override
public void run() {
try {
sendData(contacts);
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
} catch (ClientProtocolException e)
{
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e)
{
e.printStackTrace();
}
}
handler.postDelayed(this, 10000);
}
});
}
修改
您的sendData()正在执行网络通话。当应用程序尝试在其主线程上执行网络操作时，将引发此异常。你需要在另一个线程中调用sendData()方法。
答案 1 :(得分：0)
这是由于您尝试在主线程上执行的网络操作
只做一件事
public class SendContacts extends AsyncTask<Void,Void,Void>{
List<Map<String, String>> contacts;
public SendContacts(List<Map<String, String>> contacts) {
this.contacts = contacts;
}
public SendContacts() {
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
@Override
protected Void doInBackground(Void... voids) {
sendData(contacts);
return null;
}
}
您正在致电sendData(contacts);
替换为
new SendContacts(contacts).execute();