package dbpackage.jdbc;

import java.sql.*;
import java.util.Properties;
import java.io.FileInputStream;
import java.io.IOException;

/**
	The purpose of this object is to test the properites required to connect
		to an arbitrary database. The properties that this object will 
		seek are :

	database.url: The URL to use in finding the database
	database.driver: The name of the Driver class to use to connect
	database.query: An example query to ensure that a connection has been established
	
	And the follow two are optional if the database type requires them:
	
	database.user: The username of the user
	database.pass: The corresponding password for this user
		
	An example for Oracle might be:
		
	database.url=jdbc:oracle:thin:@servercsdept:1521:orcl
	database.driver=oracle.jdbc.driver.OracleDriver
	database.query=select * from Student
	database.user=username
	database.pass=password
	
	@author Michael D Elder
	@version 31-Oct-2001
 */
public class JDBCTest 
{
			
	public static void main(String[] args) 
	{
		String propFile = null;
		String dbUrl = null;
		String dbDriver = null;
		String dbQuery = null;
		String dbUser = null;
		String dbPass = null;
		
		if(args.length == 0) {
			propFile = "jdbc-example.properties";
			System.out.println("No properties file was supplied, using default of \"jdbc-example.properties\".");
		} else {
			propFile = args[0];
		}
		Properties props = new Properties();
		try {
			props.load(new FileInputStream(propFile));
		} catch(IOException ioe) {
			System.out.println("Ouch! That hurt!");
			System.out.println("Did you give me a valid file, yo?");
			ioe.printStackTrace();
			return;
		}
		
		/* load the URL and the name of the Driver */
		dbUrl = props.getProperty("database.url");
		dbDriver = props.getProperty("database.driver");
		dbQuery = props.getProperty("database.query");
		dbUser = props.getProperty("database.user");
		dbPass = props.getProperty("database.pass");
		
		/* java.sql.Connection serves as the entry point 
		   to Application-scope JDBC 
		 */
		Connection dbConn = null; 

		try {
			System.out.println("Loading Driver: \""+dbDriver+"\".");
			/* load the Driver, which will cause it to register 
			   itself with the the great DriverManager god 
			 */
			Class.forName(dbDriver).newInstance();	
		} catch (Exception e) {
			System.out.println("The driver could not be loaded.");
			e.printStackTrace();
			return;
		}
		
		try {	
			/* no username/password required */
			if(dbUser == null) {
				System.out.println("Connecting to URL: \""+dbUrl+"\".");
				/* ask the great Driver Manager god for a connection */
				dbConn = DriverManager.getConnection(dbUrl);
			/* they supplied a user name and password, we'll use it*/
			} else {
				System.out.println("Connecting to URL: \""+dbUrl+"\" as user \""+
					dbUser+"\".");
				/* ask the great Driver Manager god for a connection */
				dbConn = DriverManager.getConnection(dbUrl, dbUser, dbPass);
			}
			Statement stmt = dbConn.createStatement();
			System.out.println("Executing Query: \""+dbQuery+"\".");
			ResultSet rs = stmt.executeQuery(dbQuery);
			ResultSetMetaData rsmd = rs.getMetaData();
			int numberOfColumns = rsmd.getColumnCount();
		
			/* print header */
			for(int indx=1; indx<=numberOfColumns; ++indx) 
			{
				System.out.print(rsmd.getColumnLabel(indx) + "\t\t");
			}      	       
			System.out.println();
			System.out.println("---------------------------------------------------------");


			/* the spec defines the first call of next() to 
				aim the scroller at the first row 
      	                */
			while(rs.next()) 
			{
				for(int indx=1; indx<=numberOfColumns; ++indx) 
				{
					System.out.print(rs.getString(indx) + "\t");
				}
				System.out.println();
			}

			System.out.println("Done!");
		} catch (SQLException sqle) {
			System.out.println("Ouch! That hurt!");
			System.out.println("SQLException: " + sqle.getMessage());
			System.out.println("SQLState:     " + sqle.getSQLState());
			System.out.println("VendorError:  " + sqle.getErrorCode());			
		} catch (Exception e) {
			System.out.println("Ouch! That hurt!");
			e.printStackTrace();
		}
	}

}