java - FlatFileItemReader cannot be cast when being accessed from custom ItemReader -

i have application i'm attempting diagnose in setup i've done incorrectly, , not having luck in determining why it's not working outside of specific situations.

first code i'm using.

configuration.java

@enablebatchprocessing @springbootapplication(scanbasepackages="com.lcbo") @enableintegration public class config {      @autowired     private jobbuilderfactory jobbuilderfactory;      @autowired     private stepbuilderfactory stepbuilderfactory;      @autowired     private lcboinventorytrackerproperties inventorytrackerproperties;      @bean     public job processlcboinventory(@qualifier("getlcbostoredatastep") final step getlcbostoredatastep) {         return jobbuilderfactory                 .get("processlcboinventory")                 .incrementer(new runidincrementer())                 .start(getlcbostoredatastep)                 .build();      }      /**      * tasklet downloads .zip file, unzips, , saves in appropriate folder under resources.      * execute @ 6am daily      *      //     * @param acquiredatafiletasklet acquiredatafiles      * @return step - returns step status; either success or failure      */      @bean     public step getcurrentlcbodatastep(final acquiredatafiletasklet acquiredatafiles,                                        final executioncontextpromotionlistener listener) {         return stepbuilderfactory                 .get("getcurrentlcbodatastep")                 .tasklet(acquiredatafiles)                 .allowstartifcomplete(true)                 .listener(listener)                 .build();     }      @bean     public step getlcbostoredatastep(final lcbostorereader lcbostorereader,                                      final lcbostorewriter lcbostorewriter) {          return stepbuilderfactory                 .get("getlcbostoredatastep")                 .<lcbostore, lcbostore>chunk(inventorytrackerproperties.getdefaults().getchunksize())                 .reader(lcbostorereader)                 .writer(lcbostorewriter)                 .build();     } } 

the reader class

@component public class lcbostorereader extends abstractlcboreader implements itemreader, interstepdataretriever {      private static final logger log = loggerfactory.getlogger(lcbostorereader.class);      @override     public itemreader<lcbostore> read() throws unexpectedinputexception, parseexception, nontransientresourceexception {         class<lcbostore> classtype = lcbostore.class;          return createcsvreader(classtype, currentcsvfilepath, inventorytrackerproperties.getlcbofilpropertiess().getstores());     } /*     @override     public void beforestep(final stepexecution stepexecution) {         jobexecution jobexecution = stepexecution.getjobexecution();         executioncontext jobcontext = jobexecution.getexecutioncontext();         this.currentworkingdate = (string) jobcontext.get("currentworkingdatekey");     } */     @override     public void retrieveinterstepdatafromjobcontext(final executioncontext jobcontext) {         this.currentcsvfilepath = (string) jobcontext.get("currentcsvfilepathkey");     } } 

and class extends (because flatfileitemreader setup used multiple readers)

public abstract class abstractlcboreader {      @autowired     protected lcboinventorytrackerproperties inventorytrackerproperties;      protected string currentcsvfilepathkey;     protected string currentcsvfilepath;      private static final logger log = loggerfactory.getlogger(abstractlcboreader.class);      protected <t> itemreader<t> createcsvreader(final class<t> classtype,                                                  final string currentcsvfilepath,                                                  final lcbofiledetailsproperties properties) {          flatfileitemreader<t> reader = new flatfileitemreader<>();         // skip line ignore header information in these files         reader.setlinestoskip(properties.getnumberoflinestoskipinfile());         reader.setresource(new filesystemresource(currentcsvfilepath + file.separator + properties.getfilename()));         reader.setlinemapper(createlinemapper(classtype, properties));         reader.setrecordseparatorpolicy(new defaultrecordseparatorpolicy());         reader.setencoding("utf8");          return reader;     }      private <t> linemapper<t> createlinemapper(final class<t> classtype, final lcbofileproperties.lcbofiledetailsproperties properties) {         defaultlinemapper<t> linemapper = new defaultlinemapper<>();         linemapper.setlinetokenizer(createlinetokenizer(properties));         linemapper.setfieldsetmapper(createfieldsetmapper(classtype));          return linemapper;     }      private <t> fieldsetmapper<t> createfieldsetmapper(final class<t> classtype) {         beanwrapperfieldsetmapper<t> fieldsetmapper = new beanwrapperfieldsetmapper<>();         fieldsetmapper.settargettype(classtype);          return fieldsetmapper;     }      private linetokenizer createlinetokenizer(final lcbofileproperties.lcbofiledetailsproperties properties) {         lcbofileproperties.column[] columns = properties.getcolumns();         int[] columnindexes = new int[columns.length];         string[] columnnames = new string[columns.length];          // populating columnindexes         (int = 0; < columns.length; i++) {             columnindexes[i] = columns[i].getcolumnindex();             columnnames[i] = columns[i].getcolumnname();         }          delimitedlinetokenizer linetokenizer = new delimitedlinetokenizer();         linetokenizer.setincludedfields(columnindexes);         linetokenizer.setnames(columnnames);         linetokenizer.setdelimiter(",");         linetokenizer.setquotecharacter('"');          return linetokenizer;     } } 

the error when executing object cannot cast flatfileitemreader object passed first parameter in createcsvreader. here's example.

public class lcbostore {      private long id;     private string addresslineone;     private string addresslinetwo;     private string city;     private string postalcode;     private string latitude;     private string longitude;     private string updatedat; //convert date      public lcbostore(final long id, final string addresslineone, final string addresslinetwo, final string city,                      final string postalcode, final string latitude, final string longitude, final string updatedat) {         this.id = id;         this.addresslineone = addresslineone;         this.addresslinetwo = addresslinetwo;         this.city = city;         this.postalcode = postalcode;         this.latitude = latitude;         this.longitude = longitude;         this.updatedat = updatedat;     }      public long getid() {         return id;     }      public string getaddresslineone() {         return addresslineone;     }      public string getaddresslinetwo() {         return addresslinetwo;     }      public string getcity() {         return city;     }      public string getpostalcode() {         return postalcode;     }      public string getlatitude() {         return latitude;     }      public string getlongitude() {         return longitude;     }      public string getupdatedat() {         return updatedat;     }      public void setid(final long id) {         this.id = id;     }      public void setaddresslineone(final string addresslineone) {         this.addresslineone = addresslineone;     }      public void setaddresslinetwo(final string addresslinetwo) {         this.addresslinetwo = addresslinetwo;     }      public void setcity(final string city) {         this.city = city;     }      public void setpostalcode(final string postalcode) {         this.postalcode = postalcode;     }      public void setlatitude(final string latitude) {         this.latitude = latitude;     }      public void setlongitude(final string longitude) {         this.longitude = longitude;     }      public void setupdatedat(final string updatedat) {         this.updatedat = updatedat;     }      @override     public string tostring() {         return "storedbmodel [id=" + id + ", addresslineone=" + addresslineone + ", city=" + city                  + ", postalcode=" + postalcode + ", latitude=" + latitude + ", longitude="                 + longitude + ", updatedat=" + updatedat + "]";     } } 

now if move flatfileitemreader mode exists in createcsvreader constructor of custom reader class, or have it's in configuration file, works fine. however, couldn't figure out how work job , step context in configurations (the constructor executes before can access step , jobcontext seems testing, , never figure how access when put in config class.). plus me @ least, looks cleaner have reader code in it's own file not being stuffed in constructor.

so in nutshell, there way fix os having in it's own reader class work? doing incorrectly , using bad practices? maybe mix of two? if there's missing please ask away , i'll attempt clarify.

so found answer simple in comments. here's solution.

first, add bolded code abstract class createcsvwriter method

**protected <t> t** createcsvreader(final class<t> classtype,                                 final string currentcsvfilepath,                                 final lcbofiledetailsproperties properties) throws exception {      flatfileitemreader<t> reader = new flatfileitemreader<>();     // skip line ignore header information in these files     reader.setlinestoskip(properties.getnumberoflinestoskipinfile());     reader.setresource(new filesystemresource(currentcsvfilepath + file.separator + properties.getfilename()));     reader.setlinemapper(createlinemapper(classtype, properties));     reader.setrecordseparatorpolicy(new defaultrecordseparatorpolicy());     reader.setencoding("utf8");      **return reader.read();** } 

doing read call manually prevent returning more needed reader class. in reader class edit following

@override public **lcbostore** read() throws **exception**, unexpectedinputexception, parseexception, nontransientresourceexception {     class<lcbostore> classtype = lcbostore.class;      return createcsvreader(classtype, currentcsvfilepath, inventorytrackerproperties.getlcbofilpropertiess().getstores()); } 

this returns object you've created , hence issue resolved.