java - Incompatible types: DetailOneFragment cannot be converted to Fragment -

i have problem in code

error

incompatible types: detailonefragment cannot converted fragment in android

incompatible types: detailtwofragment cannot converted fragment in android

which wrong?

this detailactivity.java

import android.content.intnet; import android.os.bundle; import android.support.design.widget.floatingactionbutton; import android.support.design.widget.tablayout; import android.support.v4.app.fragmentmanager; import android.support.v4.view.viewpager; import android.support.v7.app.appcompatactivity; import android.view.view; import android.widget.imageview; import android.widget.textview;  import org.adnroidtown.albaplanet.r; import org.adnroidtown.albaplanet.review_view.review1activity;  public class detailactivity extends appcompatactivity {      viewpager pager;     tablayout tablayout;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_detail);          //메인 액티비티에서 넘겨받은 인텐트 -시작-         imageview iv = (imageview) findviewbyid(r.id.detail_img);         textview tvname = (textview) findviewbyid(r.id.detail_store);          intent intent = getintent();         iv.setimageresource(intent.getintextra("img", 0));         tvname.settext(intent.getstringextra("name"));          pager = (viewpager) findviewbyid(r.id.detail_viewpager);         tablayout = (tablayout) findviewbyid(r.id.tab_layout);          fragmentmanager manager = getsupportfragmentmanager();         pageradapter adapter = new pageradapter(manager);         pager.setadapter(adapter);          tablayout.setupwithviewpager(pager);         // mtablayout.setupwithviewpager(mpager1);         pager.addonpagechangelistener(new tablayout.tablayoutonpagechangelistener(tablayout));          tablayout.settabsfrompageradapter(adapter);          floatingactionbutton fab = (floatingactionbutton) findviewbyid(r.id.fab);         fab.setonclicklistener(new view.onclicklistener() {@override             public void onclick(view view) {                 intent intent = new intent(detailactivity.this, review1activity.class);                 startactivity(intent);             }         });     } } 

this pageradapter.java

import android.support.v4.app.fragment; import android.support.v4.app.fragmentmanager; import android.support.v4.app.fragmentstatepageradapter;  public class pageradapter extends fragmentstatepageradapter {     public pageradapter(fragmentmanager fm) {         super(fm);     }      @override     public fragment getitem(int position) {          fragment frag = null;         switch (position) {         case 0:             frag = new detailonefragment();             break;         case 1:             frag = new detailtwofragment();             break;         }         return frag;     }      @override     public int getcount() {         return 2;     }      @override     public charsequence getpagetitle(int position) {         string title = " ";         switch (position) {         case 0:             title = "game";             break;         case 1:             title = "movie";             break;         }         return title;     } } 

this detailonefragment.java

import android.app.fragment; import android.os.bundle; import android.view.layoutinflater; import android.view.view; import android.view.viewgroup;  import org.adnroidtown.albaplanet.r;  public class detailonefragment extends fragment {      public detailonefragment(){     // required empty public constructor     }     @override     public view oncreateview(layoutinflater inflater, viewgroup container,                          bundle savedinstancestate) {         // inflate layout fragment         return inflater.inflate(r.layout.fragment_detail_one, container, false);     } } 

this error screenshot

replace

import android.app.fragment; 

with

import android.support.v4.app.fragment; 

in fragments