小编ASM*_*RTI的帖子

我正在编写Android应用程序,其中我通过使用以下代码获取当月的那些生日朋友列表:

Calendar c = Calendar.getInstance();
int month = c.get(Calendar.MONTH) + 1;
String query = "select name, birthday, uid, pic_square from user 
where  (substr(birthday_date, 0, 2) =" + month +") AND uid IN 
(SELECT uid2 FROM friend WHERE uid1 = me()) order by birthday_date ASC";

但现在我想在接下来的30天内获取Facebook朋友的那些生日列表,我知道使用下面的当前日期获得接下来30天的java代码:

    Date today = new Date();
    Calendar cal = new GregorianCalendar();
    cal.setTime(today);
    cal.add(Calendar.DAY_OF_MONTH, +30);
    Date today30 = cal.getTime();

我知道Python查询会在接下来的30天内获取生日,但我不知道我需要在Java中使用什么代码,如果可能的话请为我替换以下用Java编写的查询: -

 query = "SELECT username …

我正在编写一个应用程序,其中我允许用户进行登录,但每当我点击登录按钮获取遗憾应用程序已停止,错误:

            java.lang.NullPointerException

引起:

DetailActivity,行号:127

   btnDisplay.setOnClickListener(new OnClickListener() 

DetailActivity,行号:62

   showInfo();

Logcat说::

04-12 10:52:06.250: E/AndroidRuntime(991): FATAL EXCEPTION: main
04-12 10:52:06.250: E/AndroidRuntime(991): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.smart.restaurant.versionoct/com.smart.restaurant.versionoct.cart.DetailActivity}: java.lang.NullPointerException
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.os.Handler.dispatchMessage(Handler.java:99)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.os.Looper.loop(Looper.java:137)
04-12 10:52:06.250: E/AndroidRuntime(991):  at android.app.ActivityThread.main(ActivityThread.java:5039)
04-12 10:52:06.250: E/AndroidRuntime(991):  at java.lang.reflect.Method.invokeNative(Native Method)
04-12 10:52:06.250: E/AndroidRuntime(991):  at java.lang.reflect.Method.invoke(Method.java:511)
04-12 10:52:06.250: E/AndroidRuntime(991):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) …