ExwpkADH

1import java.util.*;
2import java.sql.*;
3
4public class prime {
5
6	public static void main(String[] args) {
7		
8		/*
9		 * post
10		 */
11		
12		// Creating database connection
13		String db_location_mac = "jdbc:sqlite:/Users/ShaunHo/Desktop/primes.db";
14		Connection conn = null;
15		try {
16			conn = DriverManager.getConnection(db_location_mac);
17			if (conn != null) {
18				System.out.println("Created new database primes.db");
19			}
20			
21			// Wipe the table, and create a new table of primes
22			Statement stmt = conn.createStatement();
23			stmt.executeUpdate("drop table if exists primes");
24			stmt.executeUpdate("create table if not exists primes (prime integer)");
25			
26			// Use our function to get the prime numbers and store them
27			addPrimesToDB(stmt);
28			
29			// Print out all of the numbers in our 'primes' table
30			ResultSet rs = stmt.executeQuery("select prime from primes");
31			while (rs.next()) {
32				System.out.println(rs.getString(1));
33			}
34			
35		} catch (SQLException e) {
36			System.out.println(e.getMessage());
37		}
38		
39		
40	}
41	
42	/*
43	 * @pre Takes a Statement from SQLite database and adds primes to the database
44	 */
45	
46	public static void addPrimesToDB(Statement stmt) throws SQLException {
47		Scanner keyboard = new Scanner(System.in);
48		
49		System.out.print("Enter number greater than 1: ");
50		int n = keyboard.nextInt();
51		
52		boolean[] primeNumbers = new boolean[n + 1];
53		
54		for(int i = 2; i < primeNumbers.length; i++ ) {
55			primeNumbers[i] = true;}
56		
57		for(int i = 2; i < primeNumbers.length; i++) {
58			if(primeNumbers[i] == true)
59			{
60				for(int x = 0;  ; x++) 
61				{
62				int indexFalse = (int) (Math.pow(i, 2) + i*x);
63					if(indexFalse >= primeNumbers.length)
64						break;
65				primeNumbers[indexFalse] = false;
66				}
67			}
68				
69		}
70		
71		for(int i = 2; i <= n; i++ )
72		{
73			if(primeNumbers[i]) {
74				String sql_command = String.format("insert into primes (prime) values (%d)", i);
75				stmt.executeUpdate(sql_command);
76			}
77		}
78		
79	}
80
81}