ArrayList problem ....how can i remove my object.

Question

i am going to insert a cd to the arrayList , remove a cd from the arrayList, searchTheTitle, and display it...But i stuck on my remove function...i can `t remove the data that i want from the array..pls help..
//MusicCd enscaslaute the cd data
public class MusicCd
     private String musicCdsTitle;
        private int yearOfRelease;
     public MusicCd()
          musicCdsTitle = "";
          yearOfRelease = 1900;
     public MusicCd(String newMusicCdsTitle)
          musicCdsTitle = newMusicCdsTitle;
          //yearOfRelease = newYearOfRelease;
     public MusicCd(String newMusicCdsTitle, int newYearOfRelease)
          musicCdsTitle = newMusicCdsTitle;
          yearOfRelease = newYearOfRelease;
     public String getTitle()
          return musicCdsTitle;
     public int getYearOfRelease()
          return yearOfRelease;
     public void setTitle(String newMusicCdsTitle)
          musicCdsTitle = newMusicCdsTitle;
     public void setYearOfRelease(int newYearOfRelease)
          yearOfRelease = newYearOfRelease;
     public boolean equalsName(MusicCd otherCd)
          if(otherCd == null)
               return false;
          else
               return (musicCdsTitle.equals(otherCd.musicCdsTitle));
     public String toString()
          return("Music Cd`s Title: " + musicCdsTitle + "\t"
                 + "Year of release: " + yearOfRelease + "\t");
import java.util.ArrayList;
import java.io.*;
public class MusicCdStore
   ArrayList<MusicCd> MusicCdList;
   public void insertCd()
        MusicCdList = new ArrayList<MusicCd>( ); 
        readOperation theRo = new readOperation();
        MusicCd theCd;
        int muiseCdsYearOfRelease;
        String muiseCdsTitle;
          while(true)
                String continueInsertCd = "Y";
               do
                    muiseCdsTitle = theRo.readString("Please enter your CD`s title : ");
                    muiseCdsYearOfRelease = theRo.readInt("Please enter your CD`s year of release : ");
                    MusicCdList.add(new MusicCd(muiseCdsTitle, muiseCdsYearOfRelease));
                    MusicCdList.trimToSize();
                    continueInsertCd = theRo.readString("Do you have another Cd ? (Y/N) : ");
               }while(continueInsertCd.equals("Y") || continueInsertCd.equals("y") );
               if(continueInsertCd.equals("N") || continueInsertCd.equals("n"));
                                                //MusicCdList.add(new MusicCd(muiseCdsTitle, muiseCdsYearOfRelease));                              
                              break;
                  //System.out.println("You `ve an invalid input " + continueInsertCd + " Please enter (Y/N) only!!");
   public void displayAllCd()
                System.out.println("\nOur CD collection is: \n" );
          System.out.println(toString());
   public String toString( )
        String result= " ";
        for( MusicCd tempCd : MusicCdList)
             result += tempCd.toString() + "\n";
        return result;
   public void searchingMusicCd()
        readOperation theRo = new readOperation();
        String keyword = theRo.readString("Enter a CD `s Title you are going to search : ") ;
        ArrayList<MusicCd> results = searchForTitle(keyword );
          System.out.println("The search results for " + keyword + " are:" );
          for(MusicCd tempCd : results)
               System.out.println( tempCd.toString() );
   //encapsulate the A
   public void removeCd()
        readOperation theRo = new readOperation();
        String keyword = theRo.readString("Please enter CD `s title you are going to remove : ") ;
        ArrayList<MusicCd> removeMusicCdResult =searchForRemoveCdsTitle(keyword);
              System.out.println("The CD that you just removed  is " + keyword );
          for(MusicCd tempCd : removeMusicCdResult)
               System.out.println( tempCd.toString() );
   private ArrayList<MusicCd> searchForTitle(String searchString)
        ArrayList<MusicCd> searchResult = new ArrayList<MusicCd>();
        for(MusicCd currentMusicCd : MusicCdList)
             if((currentMusicCd.getTitle()).indexOf(searchString) != -1)
                  searchResult.add(currentMusicCd);
        searchResult.trimToSize();
        return searchResult;
   private ArrayList<MusicCd> searchForRemoveCdsTitle(String searchString)
        MusicCd tempCd = new MusicCd();
        tempCd.setTitle(searchString);
        ArrayList<MusicCd> removeCdsResult = new ArrayList<MusicCd>();
        for(MusicCd currentMusicCd : MusicCdList)
             if((currentMusicCd.getTitle()).equals(tempCd.getTitle()))
                  removeCdsResult.remove(currentMusicCd);
        removeCdsResult.trimToSize();
        return removeCdsResult;
private ArrayList<MusicCd> searchForRemoveCdsTitle(String searchString)
        ArrayList<MusicCd> removeCdsResult = new ArrayList<MusicCd>();
        for(MusicCd currentMusicCd : MusicCdList)
             if((currentMusicCd.getTitle()).indexOf(searchString) != -1)
                  removeCdsResult.remove(currentMusicCd);
        removeCdsResult.trimToSize();
        return removeCdsResult;
import java.util.*;
public class readOperation{
     public String readString(String userInstruction)
          String aString = null;
          try
                     Scanner scan = new Scanner(System.in);
               System.out.print(userInstruction);
               aString = scan.nextLine();
          catch (NoSuchElementException e)
               //if no line was found
               System.out.println("\nNoSuchElementException error occurred (no line was found) " + e);
          catch (IllegalStateException e)
               // if this scanner is closed
               System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
          return aString;
     public char readTheFirstChar(String userInstruction)
          char aChar = ' ';
          String strSelection = null;
          try
               //char charSelection;
                     Scanner scan = new Scanner(System.in);
               System.out.print(userInstruction);
               strSelection = scan.next();
               aChar =  strSelection.charAt(0);
          catch (NoSuchElementException e)
               //if no line was found
               System.out.println("\nNoSuchElementException error occurred (no line was found) " + e);
          catch (IllegalStateException e)
               // if this scanner is closed
               System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
          return aChar;
     public int readInt(String userInstruction) {
          int aInt = 0;
          try {
               Scanner scan = new Scanner(System.in);
               System.out.print(userInstruction);
               aInt = scan.nextInt();
          } catch (InputMismatchException e) {
               System.out.println("\nInputMismatchException error occurred (the next token does not match the Integer regular expression, or is out of range) " + e);
          } catch (NoSuchElementException e) {
               System.out.println("\nNoSuchElementException error occurred (input is exhausted)" + e);
          } catch (IllegalStateException e) {
               System.out.println("\nIllegalStateException error occurred (scanner is closed)" + e);
          return aInt;
import java.util.*;
public class MusicCdStoreEngine{
     public static void main(String[] args)
          MusicCdStore mcs = new MusicCdStore( );
          mcs.insertCd();
          //display the Cd that you just insert
          mcs.displayAllCd();
          mcs.removeCd();
          mcs.displayAllCd();
          //mcs.searchingMusicCd();
//Acutally result
//Please enter your CD`s title : ivan
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : y
//Please enter your CD`s title : hero
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : n
//Our CD collection is:
// Music Cd`s Title: ivan     Year of release: 1992
//Music Cd`s Title: hero     Year of release: 1992     
//Please enter CD `s title you are going to remove : hero
//The CD that you just removed  is hero
//Our CD collection is:
// Music Cd`s Title: ivan     Year of release: 1992
//Music Cd`s Title: hero     Year of release: 1992     
//Enter a CD `s Title you are going to search : hero
//The search results for hero are:
//Music Cd`s Title: hero     Year of release: 1992
//>Exit code: 0
//Expected result
//Please enter your CD`s title : ivan
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : y
//Please enter your CD`s title : hero
//Please enter your CD`s year of release : 1992
//Do you have another Cd ? (Y/N) : n
//Our CD collection is:
// Music Cd`s Title: ivan     Year of release: 1992
//Music Cd`s Title: hero     Year of release: 1992     
//Please enter CD `s title you are going to remove : hero
//The CD that you just removed  is hero
//Our CD collection is:
// Music Cd`s Title: ivan     Year of release: 1992
//Music Cd`s Title: hero     Year of release: 1992<<-- it is not supposed to display cos i have deleted it from from array     
//Enter a CD `s Title you are going to search : hero
//The search results for hero are:
//Music Cd`s Title: hero     Year of release: 1992<<-- i should have get this reuslt...cos it is already delete from my array
//>Exit code: 0

Answer 1

(1) searchForRemoveCdsTitle() removes rather than adds the CDs that it finds to
the list that it returns.So searchForRemoveCdsTitle() should be:private ArrayList<MusicCd> searchForRemoveCdsTitle(String searchString)
        MusicCd tempCd = new MusicCd();
        tempCd.setTitle(searchString);
        ArrayList<MusicCd> removeCdsResult = new ArrayList<MusicCd>();
        for(MusicCd currentMusicCd : MusicCdList)
            if((currentMusicCd.getTitle()).equals(tempCd.getTitle()))
                //removeCdsResult.remove(currentMusicCd);
                removeCdsResult.add(currentMusicCd); // <-- changed
        removeCdsResult.trimToSize();
        return removeCdsResult;
(2) In removeCd() you never actually remove the CDs from the array list, you just
print them to System.outSo removeCd() should be:public void removeCd()
        readOperation theRo = new readOperation();
        String keyword = theRo.readString("Please enter CD `s title you are going to remove : ") ;
        ArrayList<MusicCd> removeMusicCdResult =searchForRemoveCdsTitle(keyword);
        System.out.println("The CD that you just removed  is " + keyword );
        for(MusicCd tempCd : removeMusicCdResult)
            //System.out.println( tempCd.toString() );
            MusicCdList.remove(tempCd); // <-- changed
    }With these changes we get:Please enter your CD`s title : ivan
Please enter your CD`s year of release : 1234
Do you have another Cd ? (Y/N) : y
Please enter your CD`s title : hero
Please enter your CD`s year of release : 4321
Do you have another Cd ? (Y/N) : n
Our CD collection is:
Music Cd`s Title: ivan     Year of release: 1234     
Music Cd`s Title: hero     Year of release: 4321     
Please enter CD `s title you are going to remove : hero
The CD that you just removed  is hero
Our CD collection is:
Music Cd`s Title: ivan     Year of release: 1234     This "works", but I can't do more than hope that it helps. Really if something is unclear about either of these points it might be more productive to ask about that.