sqlite - Android SQLiteOpenHelper NullPointerException on getwritabledatabase() -


i'm search hours solution following problem:

i'm using sqlite database androidapplication:

openhelper extends sqliteopenhelper

public openhelper(context context) {     super(context, "ukra.db", null, 1); }  @override public void oncreate(sqlitedatabase database) {     database.execsql("create table client_version (integer myid primary key)");     database.execsql("insert client_version values ('0')"); }

the openhelper used class databaseloader:

private context context; private sqlitedatabase db; private openhelper openhelper;  public databaseloader(context context){     //constructor     this.context = context;     this.opendb(); }  public void opendb(){     this.openhelper = new openhelper(this.context);     system.out.println("database = " +openhelper);     try{         db = this.openhelper.getwritabledatabase();     }catch(exception ex){         ex.printstacktrace();     }     system.out.println("database = " +db); }

i create databaseloader in levelcoordinator:

private levelcoordinator(context context) {     this.context = context;     this.dbloader = new databaseloader(this.context);     this.level = new boolean[] { true, false, false }; }  public static levelcoordinator getinstance(context context) {     if (instance == null){         instance = new levelcoordinator(context);     }     return instance; }

the levelcoordinator gets context activity:

public class ukra extends activity { private levelcoordinator lc = levelcoordinator.getinstance(this); //... }

the problem nullpointerexception wich thrown call getwritabledatabase

w/system.err(  359): java.lang.nullpointerexception w/system.err(  359):    @ android.content.contextwrapper.openorcreatedatabase(contextwrapper.java:203) w/system.err(  359):    @ android.database.sqlite.sqliteopenhelper.getwritabledatabase(sqliteopenhelper.java:98) w/system.err(  359):    @ de.htw.f4.ai.s4.logic.database.databaseloader.opendb(databaseloader.java:28) w/system.err(  359):    @ de.htw.f4.ai.s4.logic.database.databaseloader.<init>(databaseloader.java:21) w/system.err(  359):    @ de.htw.f4.ai.s4.logic.levelcoordinator.<init>(levelcoordinator.java:26) w/system.err(  359):    @    de.htw.f4.ai.s4.logic.levelcoordinator.getinstance(levelcoordinator.java:35) w/system.err(  359):    @ de.htw.f4.ai.s4.ukra.<init>(ukra.java:17) w/system.err(  359):    @ java.lang.class.newinstanceimpl(native method) w/system.err(  359):    @ java.lang.class.newinstance(class.java:1429) w/system.err(  359):    @ android.app.instrumentation.newactivity(instrumentation.java:1021) w/system.err(  359):    @ android.app.activitythread.performlaunchactivity(activitythread.java:2577) w/system.err(  359):    @ android.app.activitythread.handlelaunchactivity(activitythread.java:2679) w/system.err(  359):    @ android.app.activitythread.access$2300(activitythread.java:125) w/system.err(  359):    @ android.app.activitythread$h.handlemessage(activitythread.java:2033) w/system.err(  359):    @ android.os.handler.dispatchmessage(handler.java:99) w/system.err(  359):    @ android.os.looper.loop(looper.java:123) w/system.err(  359):    @ android.app.activitythread.main(activitythread.java:4627) w/system.err(  359):    @ java.lang.reflect.method.invokenative(native method) w/system.err(  359):    @ java.lang.reflect.method.invoke(method.java:521) w/system.err(  359):    @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:868) w/system.err(  359):    @ com.android.internal.os.zygoteinit.main(zygoteinit.java:626) w/system.err(  359):    @ dalvik.system.nativestart.main(native method)

has idea why there nullpointer , how can solve it?


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