How to sort a object vector by its integer item ?

Question

hi everybody,
[there were few topics on this in the forum, but nothing could solve my problem yet. so, please instruct me]
I have to sort a vector which contains objects, where each object represents, different data types of values,
ex: {obj1, obj2, obj3, ....}
obj1---->{String name, int ID, String[] departments}
i have to sort this vector at three times, once by name, then by ID and then by departments.
Leaving name and department , first i want to sort the ID of each object and then re-arrange the order of objects in the array according to new order.
what i did was, copied the vector all objects' ID values to an integer array then i sorted it using selection sort. but now i want to re-arrange the vector, but i still can't. please guide.
here is the sort i did, and the
int[] ID = new int[mintomaxID.size()];
          for(int i=0;i<mintomaxID.size();i++)
               ObjectStore_initialData obj_id = (ObjectStore_initialData)mintomaxID.elementAt(i);
               ID[i] = obj_id.getID();
          System.out.println("Before sorting array");
          for(int i=0;i<ID.length;i++)
               System.out.println(ID);     
          System.out.println();
          int i, j, m, mi;
for (i = 0; i < ID.length - 1; i++) {
/* find the minimum */
mi = i;
for (j = i+1; j < ID.length; j++) {
if (ID[j] < ID[mi]) {
mi = j;
m = ID[mi];
/* move elements to the right */
for (j = mi; j > i; j--) {
ID[j] = ID[j-1];
ID[i] = m;
System.out.println("After sorting array");
for(int y=0;y<ID.length;y++)
               System.out.println(ID[y]);     
//*****here is where i need to re-arrange the entire vector by ID.
I do understand this is some sort of database sort type of a question. but there's no database. it's simply i just want to sort the vector.
Thank you.

Answer 1

hi camickr,
thank you for the detailed reply. but i still don't understand somethings. i tried to read the API and look for the collections.
i have ObjectStore_initialData class (similar to person class), so do i still have to do a comparable class out of this class ? please simplify that.
public class ObjectStore_initialData
     String NAME;
     int ID;
     String[] DPART;     
     public ObjectStore_initialData(String name, int id, String[] departments)
          NAME=name;
          ID=id;
          DPART = departments;
public String getName()//----
          return NAME;
public String getID()//----
          return ID;
public String getDpart()//----
          return DPART;
/*next class is the interface to collect the values from the user and put all of them at once in a vector*/
//this class is to sort the vector by ID
public class sorter
   public sorter()
   public static void sortbyID(Vector mintomaxID)
         int[] ID = new int[mintomaxID.size()];
          for(int i=0;i<mintomaxID.size();i++)
               ObjectStore_initialData obj_id = (ObjectStore_initialData)mintomaxID.elementAt(i);
               ID[i] = obj_id.getID();
          System.out.println("Before sorting array");
          for(int i=0;i<ID.length;i++)
               System.out.println(ID);     
          System.out.println();
          int i, j, m, mi;
for (i = 0; i >< ID.length - 1; i++) {
/* find the minimum */
mi = i;
for (j = i+1; j < ID.length; j++) {
if (ID[j] < ID[mi]) {
mi = j;
m = ID[mi];
/* move elements to the right */
for (j = mi; j > i; j--) {
ID[j] = ID[j-1];
ID[i] = m;
System.out.println("After sorting array");
for(int y=0;y<ID.length;y++)
               System.out.println(ID[y]);     
//*****here is where i need to re-arrange the entire vector by ID.
/*new comparable class */
public class ObjectStore_initialData implements Comparable
     String NAME;
     int ID;
     String[] DPART;     
     public ObjectStore_initialData(String name, int id, String[] departments)
          NAME=name;
          ID=id;
          DPART = departments;
public String getName()//----
          return NAME;
public String getID()//----
          return ID;
public String getDpart()//----
          return DPART;
static class IDComparator implements Comparator
          public int compare(Object o1, Object o2)
               ObjectStore_initialData p1 = (ObjectStore_initialData )o1;
               ObjectStore_initialData p2 = (ObjectStore_initialData )o2;
               return p1.getID() - p2.getID();
/*how can i put the vector here to sort? */
public sorter()
public static void sortbyID(Vector mintomaxID)
int[] ID = new int[mintomaxID.size()];
          for(int i=0;i<mintomaxID.size();i++)
               ObjectStore_initialData obj_id = (ObjectStore_initialData)mintomaxID.elementAt(i);
               ID[i] = obj_id.getID();
          System.out.println("Before sorting array");
          for(int i=0;i<ID.length;i++)
               System.out.println(ID[i]);     
          System.out.println();
          int i, j, m, mi;
for (i = 0; i >< ID.length - 1; i++) {
/* find the minimum */
mi = i;
for (j = i+1; j < ID.length; j++) {
if (ID[j] < ID[mi]) {
mi = j;
m = ID[mi];
/* move elements to the right */
for (j = mi; j > i; j--) {
ID[j] = ID[j-1];
ID[i] = m;
System.out.println("After sorting array");
for(int y=0;y<ID.length;y++)
               System.out.println(ID[y]);     
/* using collections to sort*/
Collections.sort(mintomaxID, new IDComparator());
and to check the new order i wanted to print the vector to command line.
still it doesn't do anything.
the url you mentioned is good as i see. but how can i implement that in my class ? please instruct and simplify. i know i just repeated the code, i didn't understand to do a comparable class in collections for this class. Please explain where i'm head to and where's my misleading point here.
Thank you.
Message was edited by:
ArchiEnger.711