java - Null pointer exception, taking data form lists and arrays -

i've checked several time, can't wrong..

main class:

    try     {         file productdata = new file("productdata.txt");         product [] consideredrange = inputfiledata                                           .readproductdatafile(productdata);          electronicsequipmentsupplier management =                     new electronicsequipmentsupplier(1, 12, consideredrange);             file customerdata = new file("customerdata.txt");         scanner filescan = new scanner(customerdata);          while(filescan.hasnext())             management.addnewcustomer(inputfiledata.                                                 readcustomerdata(filescan));                 management.addnewpurchaseorder("21/01/12", "psc-1235", "kd/9767", 50);                  }     catch(exception e)     {         system.out.println(e);         e.printstacktrace();     }    

inputfiledata class works perfectly. have created object of electronicsequipmentsupplier consideredrange of products. added customers customerslist.

here electronicsequipmentsupplier class:

    public class electronicsequipmentsupplier      {          private int currentmonth;          private int currentyear;          private product [] productrange;          private customerdetailslist customerslist;          private purchaseorderlist currentyearlist;          private purchaseorderlist lastyearlist;       public electronicsequipmentsupplier(int currentmonth, int currentyear, product [] range)     {          this.currentmonth = currentmonth;          this.currentyear = currentyear;          productrange = new product[range.length];          customerslist = new customerdetailslist();          currentyearlist = new purchaseorderlist();          lastyearlist = new purchaseorderlist();     }      public void addnewpurchaseorder(string datestr, string customerid,           string productcode, int qty) throws incorrectpurchaseorderexception     {     // check positive order quantity     if(qty < 1)         throw new incorrectpurchaseorderexception("order quantity must be"                                                             + " positive!");      // check product code in given range , product      product foundproduct = null;      for(int = 0; < productrange.length; i++)     {            if(productrange[i].getproductcode().equals(productcode))         {                foundproduct = productrange[i];             break;         }     }     if(foundproduct == null)         throw new incorrectpurchaseorderexception("product code not in"                                                    + " product range!");     try     {            // creating orderdate object , getting appropriate discount         orderdate newdate = new orderdate(datestr);         int discount = customerslist.findcustomer(customerid).                                                           getdiscountrate();          // creating purchase order , adding list         purchaseorder givenorder = new purchaseorder(newdate, customerid,                                                 foundproduct, qty, discount);          currentyearlist.addpurchaseorder(givenorder);          // updating record of purchasing customer         int pricevalue = givenorder.getfullpricevalue();         customerslist.findcustomer(customerid)                                         .updatetotalordersvalue(pricevalue);     }     catch(exception e)     {            throw new incorrectpurchaseorderexception("the problem with: "                                                                 + "\n" + e);     } } 

it shows i've got nullpointerexception at: if(productrange[i].getproductcode().equals(productcode))

and in main class at:

management.addnewpurchaseorder("21/01/12", "psc-1235", "kd/9767", 50);

can't why, have required info..

thank you!

update 1:

added main method solve first issue:

            for(int = 0; < consideredrange.length; i++)             management.getproductrange()[i] = consideredrange[i]; 

but id of customer cannot found... that's method in customerdetailslist class, throws exception:

public customerdetails findcustomer(string givenid)                                             throws customernotfoundexception {        int = 0;     boolean match = false;      while(!match && < listofcustomerdetails.size())     {         match = listofcustomerdetails.get(i).getcustomerid()                                                            .equals(givenid);          i++;     }      if(!match)         throw new customernotfoundexception("the provided id has not been"                                                                 + " found");     else         return listofcustomerdetails.get(i); }  

update 2: updated .findcustomer() sma suggested

you trying initialize product in constructor like

productrange = new product[range.length]; 

and using like:

if(productrange[i].getproductcode().equals(productcode)) 

now allocated space array individual array elements i.e. products not initialized , hence nullpointerexception. resolve issue, like:

productrange[i] = new product(..);//and use