Java Programming Forums - The Java Community - Collections and Generics

Java 1.4 Array issues - controlling array size for dynamic usage

doonan79 — Mon, 17 Jun 2013 16:14:46 GMT

I am working on a system and restricted to using Java 1.4
I have some working code but when declaring an Array I am having to set an Array size large enough to provide for now and the future (as Generics such as ArrayLists and Collections don't seem possible until 1.5). The issue is then when I read through the Array my code crashes at the first null value.

Now I can program to check for the null value and exit the read through, but is there a better way in 1.4? How would you best go about a dynamically sized array in 1.4?

Snippet:

String query = "select Partition.* from Partition where Name like 'SS%'";
if(debug) jcsOut.println("Finding Partitions");

String[][] partitions = new String[800][3];
int i = 0;

for (Iterator it = jcsSession.executeObjectQuery(query, null); it.hasNext();)
{
Partition p = (Partition) it.next();

if(debug) jcsOut.println(p.getName());
partitions[i][0] = p.getName();

if(p.getName().substring(2,4).equals("BA"))
{
//jcsOut.println("MATCH");
if(debug) jcsOut.println(p.getName().substring(2,4));
partitions[i][1] = p.getName().substring(2,4);
if(debug) jcsOut.println(p.getName().substring(5,9).replace( "_","")+p.getName().substring(9).replace("_","-"));
partitions[i][2] = p.getName().substring(5,9).replace("_","")+p.getNa me().substring(9).replace("_","-");
} else if (p.getName().substring(0,2).equals("SS"))
{
//jcsOut.println("MATCH");
if(debug) jcsOut.println(p.getName().substring(0,2));
partitions[i][1] = p.getName().substring(0,2);
}

if(debug) jcsOut.println(" ");

i++;
}

Binding object

marcobelli — Fri, 31 May 2013 15:41:34 GMT

I have an Object A that contains more elements, and i have an object B that is equal to A.
If A elements contains value, how can set B with same value?
Thanks.

How to fix this class/program

profit7 — Wed, 29 May 2013 12:01:54 GMT

Last week we received a test about Java Fundamentals and I wasn't able to finish it, I was wondering if someone could explain it to how to get it done.
The task was this:
Complete the program with collections, generics,... to get this output:

Room 11 has Hans Desmet as it's teacher
Felix De Vliegher follows basis
Koen Vanhoutte follows java
Serge Vereecke follows java
Freddy Himpe follows .net

Room 11 has Hans Desmet as it's teacher
There are 4 cursisten
Felix De Vliegher follows C++
Serge Vereecke follows java
Freddy Himpe follows .net
Alexandra Blondeel follows java

and this was given

Code Java:

 public class Main  {   
 
 
    public static void main(String[] args) {
 
       Traject traject1 = new Traject("c++");
       Traject traject2 = new Traject("java");
       Traject traject3 = new Traject(".net");
       Traject traject4 = new Traject("basis");
       Cursist cursist1 = new Cursist("Felix"   , "De Vliegher"  ,  traject4);
       Cursist cursist2 = new Cursist("Koen"    , "Vanhoutte,"   ,  traject2);
       Cursist cursist3 = new Cursist("Serge"   , "Vereecke"     ,  traject2);
       Cursist cursist4 = new Cursist("Freddy"  , "Himpe"        ,  traject3);
       Instructeur instructeur = new Instructeur("Hans","Desmet");
       Lokaal lokaal = new Lokaal(11, instructeur);
       lokaal.add(cursist1);
       lokaal.add(cursist2);
       lokaal.add(cursist3);
       lokaal.add(cursist4);
       System.out.println(lokaal);
       cursist1.setTraject(traject1);
       Cursist cursist5 = new Cursist("Alexandra" , "Blondeel", traject2);
       lokaal.remove(cursist2);
       System.out.println(lokaal);
 
 
    }
}

--- Update ---

So far I made these classes:
i think in class Lokaal is everything wrong but I have no idea how to fix it....

Code Java:

public class Traject {
    public Traject(String traject) {
        setTraject(traject);        
    }
 
    private String traject;
 
    public String getTraject() {
        return traject;
    }
 
    public void setTraject(String traject) {
        this.traject = traject;
    }
    @Override
     public String toString(){
         return traject;
     }
 
 
}

Code Java:

public class Lokaal extends Main {
 
    private int nr;
    private int aantalCursisten;
 
    public Lokaal(int nr, Cursist cursist, Traject traject){
        setNr(nr);       
    }
 
    public Lokaal(int nr, Instructeur instructeur){}
 
 
    public int getNr() {
        return nr;
    }
 
    private void setNr(int nr) {
        this.nr = nr;
    }
 
    public void aantalCursisten(int aantal){
        aantalCursisten += aantal;
    }
 
    public void toevoegen(Cursist cursist){
 
    }
     public void remove(Cursist cursist){
 
    }
 
}

Code Java:

public class Instructeur {
    public Instructeur(String naam, String familieNaam) {
        setNaam(naam);
        setFamilieNaam(familieNaam);
    }
 
    private String naam;
    private String familieNaam;
 
    public String getNaam(){
        return naam;
    }
 
    public String getFamilieNaam(){
        return familieNaam;
    }
 
    private void setFamilieNaam(String familieNaam){
        this.familieNaam = familieNaam;
    }
 
    private void setNaam(String naam) {
        this.naam = naam;
    }  
 
 
}

Code Java:

public class Cursist  {
    public Cursist(String naam, String familieNaam) {
        setNaam(naam);
        setFamilieNaam(familieNaam);
    }
    public Cursist(String naam, String familieNaam, Traject traject){}
 
    private String naam;
    private String familieNaam;
 
    public String getNaam() {
        return naam;
    }
 
    private void setNaam(String naam) {
        this.naam = naam;
    }
 
    public String getFamilieNaam() {
        return familieNaam;
    }
 
    private void setFamilieNaam(String familieNaam) {
        this.familieNaam = familieNaam;
    }
 
    public void setTraject(Traject traject) {
 
    }
 
}