Series #3, mga tropa.
- ire-refactor pa natin ng isa pang beses para lang mas simple and madaling basahin ang code.
- it's optional pero ang CONCEPT dito ay readability ng code, madaling intindihin at saka ilagay na natin sa isang sulok ang mga code hindi na kailangan galawin.
(TAKE NOTE: marami pang puwedeng gawin na refactoring ng DB connection like using PROPERTIES, etc o kaya ilagay sa isang utility class, etc, etc..... but for now, this is sufficient)
***Heto yung code*****
***i-compare and MainApp2 from series #2 to this MainApp3***
***para makita ang difference ng refactoring****
******NEXT TOPIC, same project, we will look at using OBJECTS para mas malinis ang ating codes. Abangan!
- ire-refactor pa natin ng isa pang beses para lang mas simple and madaling basahin ang code.
- it's optional pero ang CONCEPT dito ay readability ng code, madaling intindihin at saka ilagay na natin sa isang sulok ang mga code hindi na kailangan galawin.
(TAKE NOTE: marami pang puwedeng gawin na refactoring ng DB connection like using PROPERTIES, etc o kaya ilagay sa isang utility class, etc, etc..... but for now, this is sufficient)
***Heto yung code*****
***i-compare and MainApp2 from series #2 to this MainApp3***
***para makita ang difference ng refactoring****
Code:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
public class MainApp3 {
static Connection con;
static Statement statement;
static ResultSet resultSet;
static ResultSetMetaData rm;
static String format = "%-5s %-15s %-15s %-35s %-15s %-15s"; //pampaganda lang
/****************** This is the main entry of application ***************/
/************Let's keep it clean and easy to read ***********************/
/*******So ilagay natin sa ibat ibang methods and mga tools natin *******/
public static void main(String[] args) throws SQLException {
initDB();
String query = "SELECT * from students";
performQuery(query);
//output: print natin yung mga column names (optional)
printColumNames();
//output: loop and print ang data ng students per row
while(resultSet.next()){
System.out.println(String.format(format, resultSet.getLong(1), resultSet.getString(2),
resultSet.getString(3), resultSet.getString(4), resultSet.getString(5), resultSet.getString(6) ) );
}
}
/*************************end of Main area********************************/
/*************************************************************************/
static void initDB() throws SQLException {
String url = "jdbc:mysql://localhost/phpcorner_db";
String user = "cody";
String password = "secret";
con = DriverManager.getConnection(url, user, password);
}
static void performQuery(String query) throws SQLException {
statement = con.createStatement();
resultSet = statement.executeQuery(query);
}
static void printColumNames() throws SQLException {
rm = resultSet.getMetaData();
System.out.println(String.format(format, rm.getColumnLabel(1), rm.getColumnLabel(2),
rm.getColumnLabel(3),rm.getColumnLabel(4),rm.getColumnLabel(5),rm.getColumnLabel(6)));
}
}
******NEXT TOPIC, same project, we will look at using OBJECTS para mas malinis ang ating codes. Abangan!