listview - list view makes android app crash -

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i working on health related android app. in this, using floating action button in indexpage.java switch activity foodentry.java(having listview food items). in whenever click on floating button app crashes. 1 thing found out app crashing due listview. please me find solution of it.

this indexpage.java

public class indexpage extends appcompatactivity {  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_index_page);     toolbar toolbar = (toolbar) findviewbyid(r.id.toolbar);     setsupportactionbar(toolbar);      floatingactionbutton fab = (floatingactionbutton) findviewbyid(r.id.fab);     fab.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view view) {             intent in = new intent(indexpage.this, foodentry.class);             startactivity(in);          }     }); } }

foodentry.java

public class foodentry extends appcompatactivity {  // array of strings... string[] food = {"naan","pav bhaji","chole tikiya", "rice", "soyabean", "milk", "curd", "abc", "def", "dfadf", "fasdfa", "fsadf", "fdsfa", "fga"};  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);       arrayadapter adapter = new arrayadapter<>(this, r.layout.activity_item, food);     listview listviewfooditems = (listview)findviewbyid(r.id.listviewfood);     listviewfooditems.setadapter(adapter); } }

error on logcat

03-31 15:30:58.555 13732-13732/com.praval.healthfreak w/dalvikvm: threadid=1: calling uncaughtexceptionhandler 03-31 15:30:58.556 13732-13732/com.praval.healthfreak e/androidruntime: fatal exception: main                                                                         process: com.praval.healthfreak, pid: 13732                                                                         java.lang.runtimeexception: unable start activity componentinfo{com.praval.healthfreak/com.praval.healthfreak.foodentry}: java.lang.nullpointerexception                                                                             @ android.app.activitythread.performlaunchactivity(activitythread.java:2389)                                                                             @ android.app.activitythread.handlelaunchactivity(activitythread.java:2441)                                                                             @ android.app.activitythread.access$900(activitythread.java:151)                                                                             @ android.app.activitythread$h.handlemessage(activitythread.java:1354)                                                                             @ android.os.handler.dispatchmessage(handler.java:110)                                                                             @ android.os.looper.loop(looper.java:193)                                                                             @ android.app.activitythread.main(activitythread.java:5345)                                                                             @ java.lang.reflect.method.invokenative(native method)                                                                             @ java.lang.reflect.method.invoke(method.java:515)                                                                             @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:828)                                                                             @ com.android.internal.os.zygoteinit.main(zygoteinit.java:644)                                                                             @ dalvik.system.nativestart.main(native method)                                                                          caused by: java.lang.nullpointerexception                                                                             @ com.praval.healthfreak.foodentry.oncreate(foodentry.java:20)                                                                             @ android.app.activity.performcreate(activity.java:5343)                                                                             @ android.app.instrumentation.callactivityoncreate(instrumentation.java:1088)                                                                             @ android.app.activitythread.performlaunchactivity(activitythread.java:2343)                                                                             @ android.app.activitythread.handlelaunchactivity(activitythread.java:2441)                                                                              @ android.app.activitythread.access$900(activitythread.java:151)                                                                              @ android.app.activitythread$h.handlemessage(activitythread.java:1354)                                                                              @ android.os.handler.dispatchmessage(handler.java:110)                                                                              @ android.os.looper.loop(looper.java:193)                                                                              @ android.app.activitythread.main(activitythread.java:5345)                                                                              @ java.lang.reflect.method.invokenative(native method)                                                                              @ java.lang.reflect.method.invoke(method.java:515)                                                                              @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:828)                                                                              @ com.android.internal.os.zygoteinit.main(zygoteinit.java:644)                                                                              @ dalvik.system.nativestart.main(native method)

you forget add 

setcontentview(r.layout.activity_layout);

in foodentry activity


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