Arrays: Partial Search terms

Question

Hello and thanks for taking the time to read this question!
I've been working on a simple college search program for my APCS class, a quick description of the program: Basically it takes a specially formated text file called collegeDatabase.dat and loads it into an array of blankCollege Objects (which extend collegeAbstract, code is below)
blankCollege
public class blankCollege extends collegeAbstract
     public blankCollege()
          super();
}collegeAbstract
//Abstract College Type
//Copyright aolszowka 2006
abstract public class collegeAbstract implements collegeInterface
     protected String collegeName;
     protected String collegeTypePP; //Private or Public?
     protected int collegeSize;
     protected String collegeMascot;
     protected String collegeCityType;
     protected int collegeCost;
     protected String collegeLocation;
     //DEBUG MODE?
     protected boolean debugMode = false;
     public collegeAbstract()
          collegeName = "null";
          collegeTypePP = "null"; //Private or Public?
          collegeSize = 0;
          collegeMascot = "null";
          collegeCityType = "null";
          collegeCost = 0;
          collegeLocation = "null";
     //College Constuctor
     public void setCollege(String college_Name, String college_Location, String college_TypePP, int college_Size, String college_Mascot, String college_CityType, int college_Cost)
          collegeName = college_Name;
          collegeTypePP = college_TypePP;
          collegeSize = college_Size;
          collegeMascot = college_Mascot;
          collegeCityType = college_CityType;
          collegeCost = college_Cost;
          collegeLocation = college_Location;
     //Recall Variables
       (edited out for space sake)
     //DEBUG GOODIES
     public String toStringDebug()
          return (collegeName+" "+collegeLocation+" "+collegeTypePP+" "+collegeSize+" "+collegeMascot+" "+collegeCityType+" "+collegeCost);
}Now I figured this would be the hardest part (but thanks to the power of google and the Java Docs it wasn't :D)! So at this point I can load the database and do basic seraches like this one
searchCollege
import java.util.ArrayList;
public class searchCollege
     collegeAbstract[] collegeArray = {null};
     public searchCollege(collegeAbstract[] collegeDatabase)
          collegeArray = collegeDatabase; //This is the Database loaded from loadColleges
     public String[] searchNames(String collegeName)
          //Create Search Array
          ArrayList<String> searchingColleges = new ArrayList<String>(0);
          int answerArraySize = 0;
          for(int i=0;i<collegeArray.length;i++)
               if((collegeArray.collegeName.toUpperCase()).equals(collegeName.toUpperCase()))
                    searchingColleges.add(answerArraySize,(collegeArray[i].collegeName));
                    answerArraySize++;
          //Create Return Array
          String[] foundColleges = (String[])searchingColleges.toArray(new String[searchingColleges.size()]);
          return foundColleges;
The problem with this is that the user needs to enter in the exact name of the college, is there a way to get partial matches? Now I found a previous post about partial matches @ http://forum.java.sun.com/thread.jspa?threadID=653541&messageID=3841115 but from my understanding the array needs to be sorted, and when I attempt to sort my collegeDatabase I can't, it throws the exception "ClassCastException" so I guess I can't perform a binary search (because the array cant be sorted)?
Once again thanks for taking the time to read my problem, if you need any more information (or the whole project file) just please request and I would be happy to post it.

Answer 1

I do not understand the use of an abstract class at
all. If the abstract class implements all the methods
of the interfaces it implements then why is it
abstract?Well one of two reasons, the project(Actually the teacher) calls for 4 parts:
1. Must have an Abstract Class
2. Must have an Interface
3. Must have a child class that extends the abstract class
4. Must have a child of a child class that extends the abstract class
The Second Reason is:
From my understanding of java I want to make abstract classes when I have a problem where the data is similar across all classes that require it, thus saving work, plus it would inherited the methods defined in the abstract class saving more typing. There is also a bit more to this program I have a few "static colleges" that each have extra methods, abstracting the general college template allowed me to simply extend it, and then add additional methods for those "static colleges".
From what I also understand (although I am very new to java and programming in general) the Interface is just a list of methods that at one point or another must be defined in the class that it interfaces with?
Your array should be of the interface type and not
the implementation type most likely.Im sorry, I don't understand what you mean by this, I want the array to be of colleges in which I've defined in the abstract class, but their values are modfied by another method which loads a database with that information in it.
Here is the code of the Interface class
interface collegeInterface
     String getCollegeName();
     String getCollegeTypePP(); //Private (p) or Public (u)?
     int getCollegeSize();
     String getCollegeMascot();
     String getCollegeCityType();
     int getCollegeCost();
     String getCollegeLocation();
You do not need to sort the array to search strings
for a substring. You don't even need regex for that.
You can just use String.indexOf(String str) for that.The Variable String in this case, what is it? Is it the Array of colleges? because it is storing more data than just the name of the college?
Im sorry if I've misunderstood your answer, please bear with me I want to learn :D