我正在尝试在我的应用程序中使用带有通知的远程视图。但是当我运行我的应用程序时，我得到了E/AndroidRuntime(11337): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.jeema.HWDTest/net.jeema.HWDTest.HWDTestActivity}: java.lang.NullPointerException。不知道为什么会发生。我是 android 新手。请帮助我。无法提示为什么我在这里遇到运行时异常。
我的代码：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
notification.flags = notification.flags | Notification.FLAG_ONGOING_EVENT;
final RemoteViews contentView = new RemoteViews(getPackageName(),
R.layout.upload_progress_bar);
contentView.setProgressBar(R.id.progress_bar, MAX_PROGRESS,
mProgressStatus, false);
notification=new Notification();
notification.contentView = contentView;
// Start file upload in a background thread
new Thread(new Runnable() {
public void run() {
while (mProgressStatus < MAX_PROGRESS) {
mProgressStatus = doWork();
// Update the progress bar
mHandler.post(new Runnable() {
public void run() {
contentView.setProgressBar(R.id.progress_bar,
MAX_PROGRESS, mProgressStatus, false);
}
});
}
}
private int doWork() {
HttpURLConnection conn = null;
DataOutputStream dos = null;
DataInputStream inStream = null;
String lineEnd = "\r\n";
String twoHyphens = "--";
String boundary = "*****";
int bytesRead;
byte[] buffer;
String urlString = "http://xxxxx/xxxx/xxx.php";
try {
UUID uniqueKey = UUID.randomUUID();
fname = uniqueKey.toString();
Log.e("UNIQUE NAME", fname);
FileInputStream fileInputStream = new FileInputStream(
new File(selectedPath));
URL url = new URL(urlString);
conn = (HttpURLConnection) url.openConnection();
int length = fileInputStream.available();
System.out.println("Video Length--->>>>" + length);
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Content-Type",
"multipart/form-data;boundary=" + boundary);
dos = new DataOutputStream(conn.getOutputStream());
dos.writeBytes(twoHyphens + boundary + lineEnd);
dos.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
+ fname + "" + lineEnd);
dos.writeBytes(lineEnd);
buffer = new byte[8192];
bytesRead = 0;
while ((bytesRead = fileInputStream.read(buffer)) > 0) {
dos.write(buffer, 0, bytesRead);
}
dos.writeBytes(lineEnd);
dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
Log.e("Debug", "File is written");
fileInputStream.close();
dos.flush();
dos.close();
} catch (MalformedURLException ex) {
Log.e("Debug", "error: " + ex.getMessage(), ex);
} catch (IOException ioe) {
Log.e("Debug", "error: " + ioe.getMessage(), ioe);
}
// ------------------ read the SERVER RESPONSE
try {
inStream = new DataInputStream(conn.getInputStream());
String str;
while ((str = inStream.readLine()) != null) {
Log.e("Debug", "Server Response " + str);
}
inStream.close();
} catch (IOException ioex) {
Log.e("Debug", "error: " + ioex.getMessage(), ioex);
}
return 0;
}
}).start();
}
我的日志猫：
08-26 14:15:49.542: E/AndroidRuntime(12359): FATAL EXCEPTION: main
08-26 14:15:49.542: E/AndroidRuntime(12359): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.jeema.HWDTest/net.jeema.HWDTest.HWDTestActivity}: java.lang.NullPointerException
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.os.Handler.dispatchMessage(Handler.java:99)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.os.Looper.loop(Looper.java:123)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread.main(ActivityThread.java:3683)
08-26 14:15:49.542: E/AndroidRuntime(12359): at java.lang.reflect.Method.invokeNative(Native Method)
08-26 14:15:49.542: E/AndroidRuntime(12359): at java.lang.reflect.Method.invoke(Method.java:507)
08-26 14:15:49.542: E/AndroidRuntime(12359): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-26 14:15:49.542: E/AndroidRuntime(12359): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-26 14:15:49.542: E/AndroidRuntime(12359): at dalvik.system.NativeStart.main(Native Method)
08-26 14:15:49.542: E/AndroidRuntime(12359): Caused by: java.lang.NullPointerException
08-26 14:15:49.542: E/AndroidRuntime(12359): at net.jeema.HWDTest.HWDTestActivity.onCreate(HWDTestActivity.java:36)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-26 14:15:49.542: E/AndroidRuntime(12359): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
08-26 14:15:49.542: E/AndroidRuntime(12359): ... 11 more
我的清单.xml：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="net.jeema.HWDTest"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".HWDTestActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>