Android refresh image in viewpager -

i developing application show images using viewpager. in app, have 5 pages , each page showing 1 image. , have button can refresh 5 pages (means images different). here code:

imageadapter.java

public class imageadapter extends pageradapter {     private context context;     private list<integer> todayimage;      imageadapter(context context, list<integer> todayimage) {         this.context = context;         this.todayimage = todayimage;     }      public void setimage(list<integer> todayimage) {         this.todayimage = todayimage;     }      @override     public int getcount() {         return todayimage.size();     }      @override     public boolean isviewfromobject(view view, object object) {         return view == ((imageview) object);     }      @override     public object instantiateitem(viewgroup container, int position) {         imageview imageview = new imageview(context);         file imgfile = new file("data/data/com.project.project/"                 + todayimage.get(position) + ".jpg");         bitmap shufflebit = bitmapfactory.decodefile(imgfile.getabsolutepath());         imageview.setimagebitmap(shufflebit);         ((viewpager) container).addview(imageview, 0);         return imageview;     }      @override     public void destroyitem(viewgroup container, int position, object object) {         ((viewpager) container).removeview((imageview) object);     }      @override     public int getitemposition(object object) {         return position_none;     }      @override     public void destroyitem(view collection, int position, object view) {         ((viewpager) collection).removeview((view) view);     }  } 

this button use renew images:

shuffle.setonclicklistener(new onclicklistener() {     public void onclick(view v) {         adapter.setimage(newimage); }); 

this logcat:

05-03 01:17:50.793: e/androidruntime(716): fatal exception: main 05-03 01:17:50.793: e/androidruntime(716): java.lang.nullpointerexception 05-03 01:17:50.793: e/androidruntime(716):  @ com.example.project.main$1.onclick(main.java:201) 05-03 01:17:50.793: e/androidruntime(716):  @ android.view.view.performclick(view.java:4084) 05-03 01:17:50.793: e/androidruntime(716):  @ android.view.view$performclick.run(view.java:16966) 05-03 01:17:50.793: e/androidruntime(716):  @ android.os.handler.handlecallback(handler.java:615) 05-03 01:17:50.793: e/androidruntime(716):  @ android.os.handler.dispatchmessage(handler.java:92) 05-03 01:17:50.793: e/androidruntime(716):  @ android.os.looper.loop(looper.java:137) 05-03 01:17:50.793: e/androidruntime(716):  @ android.app.activitythread.main(activitythread.java:4745) 05-03 01:17:50.793: e/androidruntime(716):  @ java.lang.reflect.method.invokenative(native method) 05-03 01:17:50.793: e/androidruntime(716):  @ java.lang.reflect.method.invoke(method.java:511) 05-03 01:17:50.793: e/androidruntime(716):  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:786) 05-03 01:17:50.793: e/androidruntime(716):  @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 05-03 01:17:50.793: e/androidruntime(716):  @ dalvik.system.nativestart.main(native method) 

the app crashes when press button, can me how fix it? found answer using settag(), have no idea how it.