Android : Error in single item click in listview android

I follow this to create list view using json. On selecting single Iten in listview I got following error

08-05 11:50:42.957: E/AndroidRuntime(367): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.bulidersapp/com.example.bulidersapp.SingleViewNews}: java.lang.NullPointerException
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1569)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread.access$1500(ActivityThread.java:117)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.os.Looper.loop(Looper.java:123)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread.main(ActivityThread.java:3683)
08-05 11:50:42.957: E/AndroidRuntime(367):  at java.lang.reflect.Method.invokeNative(Native Method)
08-05 11:50:42.957: E/AndroidRuntime(367):  at java.lang.reflect.Method.invoke(Method.java:507)
08-05 11:50:42.957: E/AndroidRuntime(367):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
08-05 11:50:42.957: E/AndroidRuntime(367):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
08-05 11:50:42.957: E/AndroidRuntime(367):  at dalvik.system.NativeStart.main(Native Method)
08-05 11:50:42.957: E/AndroidRuntime(367): Caused by: java.lang.NullPointerException
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.content.ContextWrapper.getCacheDir(ContextWrapper.java:188)
08-05 11:50:42.957: E/AndroidRuntime(367):  at com.example..FileCache.<init>(FileCache.java:19)
08-05 11:50:42.957: E/AndroidRuntime(367):  at com.example..ImageLoader.<init>(ImageLoader.java:34)
08-05 11:50:42.957: E/AndroidRuntime(367):  at com.example..SingleViewNews.<init>(SingleViewNews.java:17)
08-05 11:50:42.957: E/AndroidRuntime(367):  at java.lang.Class.newInstanceImpl(Native Method)
08-05 11:50:42.957: E/AndroidRuntime(367):  at java.lang.Class.newInstance(Class.java:1409)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
08-05 11:50:42.957: E/AndroidRuntime(367):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)
08-05 11:50:42.957: E/AndroidRuntime(367):  ... 11 more

Please help me to resolve this issue