Java question help (applying binary search)

Question

please show me how do i apply a binary search inside this program where i can use the binary serach to search for the book author or book title
// objectSort.java
// demonstrates sorting objects (uses bubble sort)
// to run this program: C>java libmainsys
class libary
private String booktitle;
private String bookauthor;
private String publisher;
private int yearpublished;
private int edition;
private int nofcop;
public libary(String title, String author, String pub, int yrpub, int edt, int nfcp)
{                // constructor
booktitle = title;
bookauthor = author;
publisher = pub;
yearpublished = yrpub;
edition = edt;
nofcop = nfcp;
public void displaylibary()
System.out.print(" Book Title: " + booktitle);
System.out.print(", Book Author: " + bookauthor);
System.out.print(", Book Publisher: " + publisher);
System.out.print(", Year Published: " + yearpublished);
System.out.print(", Edition: " + edition);
System.out.println(",No Of Copies : " + nofcop);
public String getLast() // get title
{ return booktitle; }
} // end class libary
class ArrayInOb
private libary[] nfcp; // ref to array ypub
private int nElems; // number of data items
public ArrayInOb(int max) // constructor
nfcp = new libary[max]; // create the array
nElems = 0; // no items yet
// put libary into array
public void insert(String title, String author, String pub, int yrpub, int edt, int nofcop)
nfcp[nElems] = new libary(title, author, pub, yrpub, edt, nofcop);
nElems++; // increment size
public void display() // displays array contents
for(int j=0; j<nElems; j++) // for each element,
nfcp[j].displaylibary(); // display it
System.out.println("");
public void bubbleSort()
int i, j;
libary temp;
for (i = nElems-1; i >= 0; i--)
for (j = 1; j <= i; j++)
if (nfcp[j-1].getLast().compareTo(nfcp[j].getLast())>0)
temp = nfcp[j-1];
nfcp[j-1] = nfcp[j];
nfcp[j] = temp;
} // end class ArrayInOb
class libmainsys
public static void main(String[] args)
int maxSize = 1000; // array size
ArrayInOb arr; // reference to array
arr = new ArrayInOb(maxSize); // create the array
arr.insert("Java_how__to_program", "Patty_John", "Deitel", 2001, 1, 430);
arr.insert("System_Design", "Dexter_Smith", "Thomson", 2002, 3, 450);
arr.insert("Program_Design", "Lorraine_Paul", "About", 1996, 2, 196);
arr.insert("Computer_Architecture", "Paul_Andrew","Dzone", 2006, 5, 199);
arr.insert("Visual_Basic_How_To_ Program", "Tom_Jones", "Jeffereson_publication", 2007, 4, 207);
arr.insert("Information_ Management", "William_Peter", "Mcgraw_Hill", 1995, 3, 204);
arr.insert("Sofware_ Application", "Henry_Sam", "Pearson", 2001, 6, 278);
arr.insert("English", "Samantha_Julia", "James_Hill", 2005, 1, 200);
arr.insert("Web_Publishing", "Audrey_Cynthia", "Surg", 2004, 3, 201);
arr.insert("Human_Computer_Interaction", "Tony_Edward", "Telde", 2003, 3, 199);
System.out.println("Before sorting:");
arr.display(); // display items
arr.bubbleSort(); // insertion-sort them
System.out.println("After sorting:");
arr.display(); // display them again
} // end main()
} // end class libmainsys

Answer 1

I see you haven't worked out bubbleSort either. Since binary search only works on sorted arrays, I suggest you start there. Do you have the algorithms somewhere?
If you really need to be able to search using either author or title, I suggest you create 2 Comparators that compare using the desired property. Comparator is just an interface that defines methods to compare 2 objects. You have to write your own implementation of it to compare library objects. You'll always have to sort and search using the same Comparator.