Cut file Java (2 by 2) -

i started in java , galley little (a lot). explain problem, have flat file , read through java. goal create multiple output files (one file per order).

in file, example have order number (136670 , 136609):

136670 00000000000000000 abc  136670 00000000000000000 abd  136670 00000000000000000 abe  136609 00000000000000000 abc  136609 00000000000000000 abd  136609 00000000000000000 abf  136609 00000000000000000 abe 

so created hashmap, or put order number 136670 , 136609. current hashmap:

key: 136670

values:

136670 00000000000000000 abc  136670 00000000000000000 abd  136670 00000000000000000 abe 

---

key: 136609

values:

136609 00000000000000000 abc  136609 00000000000000000 abd  136609 00000000000000000 abe  136609 00000000000000000 abf  136609 00000000000000000 abe 

code:

linkedhashmap<string, stringbuilder> order = new linkedhashmap<string, stringbuilder>(); while((line = br.readline()) != null){     string lineid = line.substring(order_start_position, order_end_position);     if(order.get(lineid) != null){         stringbuilder stringbuilder = order.get(lineid);         stringbuilder.append("\n"+(line));         order.put(lineid, stringbuilder);     }     else{         order.put(lineid, new stringbuilder(line));         } }    

i put of code. use linkedhashmap output file.

my code works not arrive 2 things necessary me:

• if number of input values in linkedhashmap greater 2, want create new hashmap, 4 want new hashmap.

• if number of input values in linkedhashmap greater 2, want increment figure of 800, if equal 4-801 on.

for example example file:

key: 136670

values:

136670 00000000000000000 abc  136670 00000000000000000 abd 

with 800.

---

key: 136670

values:

136670 00000000000000000 abe 

with code 801.

---

key: 136609

values:

136609 00000000000000000 abc  136609 00000000000000000 abd 

with 800.

---

key: 136609

values:

136609 00000000000000000 abe  136609 00000000000000000 abf 

with code 801.

---

key: 136609

values:

136609 00000000000000000 abe 

with code 802.

---

i thought go through hashmap, linkedhashmap treemap can not cut hashmap several subfiles ...

i tested way:

if (i % 2 == 0) {     } 

and list of hashmap: list<hashmap<string, stringbuilder>> maps = new arraylist<>(); doesn't work.

do have idea success division?

thank in advance.

i hope code serve example of need do

public static void main(string[] args) throws ioexception {     bufferedreader br = new bufferedreader(new filereader("input.txt"));      // map holds orders     // each order, have list of orderitems     // orderitems list of string     map<string, list<list<string>>> map = new linkedhashmap<>();     string line;     while((line = br.readline()) != null){         string orderid = line.substring(0, 6);          // find order         list<list<string>> order = map.get(orderid);         // if dont have yet, lets create         if (order == null) {             order = new arraylist<>();             map.put(orderid, order);         }          list<string> orderitems;         // if our order empty, no items @ all, create first group of items         if (order.isempty()) {             orderitems = new arraylist<>();             order.add(orderitems);         } else {             // otherwise last group of items             orderitems = order.get(order.size()-1);         }          // if group, have 2 items, create new 1         if (orderitems.size() == 2) {             orderitems = new arraylist<>();             order.add(orderitems);         }          // add item, group (orderitems)         orderitems.add(line);     }        br.close();      // lets check if worked      (string orderid: map.keyset()) {         system.out.println("orderid: "+orderid);         list<list<string>> order = map.get(orderid);         int groupid = 800;         (list<string> orderitems: order) {             system.out.println("  group: "+groupid);             (string item: orderitems)                 system.out.println("    "+item);             groupid++;         }     } } 

here's input.txt

136670 00000000000000000 abc 136670 00000000000000000 abd 136670 00000000000000000 abe 136609 00000000000000000 abc 136609 00000000000000000 abd 136609 00000000000000000 abe 136609 00000000000000000 abf 136609 00000000000000000 abe 

here's output:

orderid: 136670   group: 800     136670 00000000000000000 abc     136670 00000000000000000 abd   group: 801     136670 00000000000000000 abe orderid: 136609   group: 800     136609 00000000000000000 abc     136609 00000000000000000 abd   group: 801     136609 00000000000000000 abe     136609 00000000000000000 abf   group: 802     136609 00000000000000000 abe