java - Populate an array of objects using hashmap -

i new hashmaps , though trying read it, couldn't solve issue.

this part of code have issue.

public heatmapdata(hashmap<node, arraylist<oddata>> ods) {     /* of origins */     node [] row = ods.keyset().toarray(new node[0]);     node [] column = new node[row.length];     system.arraycopy(row, 0, column, 0, row.length);      oddata [] routes = new oddata[routes_size];           (int i=0; i<routes_size; i++)     {         oddata temp = new oddata();         // node n = row[i];          routes[i] = temp;          //routes = (oddata[]) ods.get(n).toarray(new oddata[0]);                 } 

as can see can't find way copy data original hashmap array of objects.

i need find first node in array "row", find values hashmpap, populate array "routes[]", , same second node in array "row". seems every time try have miss match error or null value.

the program reads 2 files follows:

first:

100001 200002 6 100001 200003 9 ............... 

second:

100001 -97.5489 30.5846 100002 -97.6958 30.5986 ............... 

my node class consists of

int id; double longititude; double lattitude; 

and oddata class consists of

node origin; node destination; double value; 

each 10000 number has many 20000 numbers relating it.

using hashmap being send function, need populate oddata routes[] array these oddata objects original file (the first one).

any idea how can done? i'll appreciate help!

nikita

you have iterate hash map , value of map , convert arraylist (value of hash map) array using toarray() of arraylist. in design routes array has limited size, have memory wastage.

public class fetchmapdata {

static final int routes_size = 10;  public void heatmap(hashmap<string, arraylist<oddata>> map) {      int totallength = 0;      arraylist<oddata> alist = new arraylist<oddata>();      oddata[] routes = new oddata[routes_size];     oddata[] tmproutes = new oddata[routes_size];      (string key : map.keyset()) {         alist = map.get(key);         // have impact array size limited         // routes_size         tmproutes = alist.toarray(new oddata[alist.size()]);         system.arraycopy(tmproutes, 0, routes, totallength,                 tmproutes.length);         totallength = totallength + tmproutes.length;     }     (int = 0, length = routes.length; < length; i++) {         if (routes[i] != null) {             system.out.println(routes[i].getorigin() + "        "                     + routes[i].getdestination() + "        "                     + routes[i].getvalue());         }     } }  public static void main(string[] args) {     hashmap<string, arraylist<oddata>> heatmap = new hashmap<string, arraylist<oddata>>();      arraylist<oddata> list1 = new arraylist<oddata>();     arraylist<oddata> list2 = new arraylist<oddata>();     oddata obj1 = new oddata("s1", "s2", 1.1);     oddata obj2 = new oddata("s3", "s4", 2.1);     oddata obj3 = new oddata("s5", "s6", 3.1);     oddata obj4 = new oddata("s7", "s8", 4.1);     list1.add(obj1);     list1.add(obj2);     list2.add(obj3);     list2.add(obj4);     heatmap.put("key1", list1);     heatmap.put("key2", list2);      fetchmapdata fetchmapdataobj = new fetchmapdata();     fetchmapdataobj.heatmap(heatmap); } 

}

output:

s5      s6      3.1 s7      s8      4.1 s1      s2      1.1 s3      s4      2.1 

you modify string in hashmap node per requirement. if want maintain sorting order use treemap instead of hashmap.