Student.java

public class Student {
	private String Search;
	
	public void setSearch(String keyword) {
		keyword = Search;
	}
	
	public String getSearch() {
		return Search;
	}
}

StudentInformation.java

import java.util.*;
import java.io.IOException;

public class StudentInformation {

	public static void main(String[] args) throws IOException {
		int choice;
		StudentSearch student = new StudentSearch();
		Scanner scan = new Scanner(System.in);
		
		System.out.print("Select menu to search (1 = ID, 2 =  Front name, 3 = Name, 4 = LastName) : ");
		
		try {
			choice = scan.nextInt();
			
			if (choice == 1) {
				System.out.print("Enter ID : ");
				
				if (student.SearchByID(scan.next())) {
					student.show();
				}
				else {
					System.out.println("Data not found.");
				}
				
			}
			else if (choice == 2) {
				System.out.print("Enter Frontname : ");
				
				if (student.SearchByFrontName(scan.next())) {
					student.show();
				}
				else {
					System.out.println("Data not found.");
				}
				
			}
			else if (choice == 3) {
				System.out.print("Enter Name : ");
				
				if (student.SearchByName(scan.next())) {
					student.show();
				}
				else {
					System.out.println("Data not found.");
				}
				
			}
			else if (choice == 4) {
				System.out.print("Enter Lastname : ");
				
				if (student.SearchByID(scan.next())) {
					student.show();
				}
				else {
					System.out.println("Data not found.");
				}
				
			}
			else {
				System.out.println("Choice wrong.");
			}
		}
		catch (Exception ex) {
			System.out.println(ex.getMessage());
		}
		finally {
			scan.close();
		}
	}

}

StudentSearch.java

import java.io.*;
import java.util.*;

public class StudentSearch extends Student {
	private String ID;
	private String FrontName;
	private String Name;
	private String Lastname;
	private String[][] StudentInfo;
	private String[] StudentInfoByFront;
	
	public StudentSearch() throws IOException {
		int lineNumber = 0;
		Scanner findLineNumber = new Scanner(new File("D:/Student List.txt"));
		
		while (findLineNumber.hasNextLine()) {
			findLineNumber.nextLine();
			lineNumber++;
		}
		
		findLineNumber.close();
		StudentInfo = new String[lineNumber][4];
		Scanner in = new Scanner(new File("D:/Student List.txt"));
		
		for (int i = 0; i < lineNumber; i++) {
			StudentInfo[i][0] = in.next();
			StudentInfo[i][1] = in.next();
			StudentInfo[i][2] = in.next();
			StudentInfo[i][3] = in.next();
		}
		
		in.close();
	}
	
	public boolean SearchByID(String id) {
		for (int i = 0; i < StudentInfo.length; i++) {
			if (id.equalsIgnoreCase(StudentInfo[i][0])) {
				ID = StudentInfo[i][0];
				FrontName = StudentInfo[i][1];
				Name = StudentInfo[i][2];
				Lastname = StudentInfo[i][3];
				
				return true;
			}
		}
		
		return false;
	}
	
	public boolean SearchByFrontName(String front) {
		if (!front.equalsIgnoreCase("miss") && !front.equals("mr.")) {
			return false;
		}
		
		int lineNumber = 0;
		
		for (int i = 0; i < StudentInfo.length; i++) {
			if (front.equalsIgnoreCase(StudentInfo[i][1])) {
				lineNumber++;
			}
		}
		
		StudentInfoByFront = new String[lineNumber];
		lineNumber = 0;
		
		for (int i = 0; lineNumber < StudentInfoByFront.length; i++) {
			if (front.equalsIgnoreCase(StudentInfo[i][1])) {
				StudentInfoByFront[lineNumber] = StudentInfo[i][0] + " " 
						+ StudentInfo[i][1] + " " + StudentInfo[i][2] + " " + StudentInfo[i][3];
				lineNumber++;
			}
		}
		
		return true;
	}
	
	public boolean SearchByName(String name) {
		for (int i = 0; i < StudentInfo.length; i++) {
			if (name.equalsIgnoreCase(StudentInfo[i][2])) {
				ID = StudentInfo[i][0];
				FrontName = StudentInfo[i][1];
				Name = StudentInfo[i][2];
				Lastname = StudentInfo[i][3];
				
				return true;
			}
		}
		
		return false;
	}
	
	public boolean SearchByLastname(String lastname) {
		for (int i = 0; i < StudentInfo.length; i++) {
			if (lastname.equalsIgnoreCase(StudentInfo[i][3])) {
				ID = StudentInfo[i][0];
				FrontName = StudentInfo[i][1];
				Name = StudentInfo[i][2];
				Lastname = StudentInfo[i][3];
				
				return true;
			}
		}
		
		return false;
	}
	
	public void show() {
		if (ID != null) {
			System.out.println("Data Found : " + ID + " " + FrontName + " " + Name + " " + Lastname);
		}
		else {
			System.out.println("Data Found : " + StudentInfoByFront[0]);
			
			for (int i = 1; i < StudentInfoByFront.length; i++) {
				System.out.println("\t   : " + StudentInfoByFront[i]);
			}
		}
	}

}