I am trying to execute simple query using below DbQuery.java class which uses DbConnector to get a Connection from DriverManager.
note:
- I have already included "mysql-connector-java-5.1.25-bin.jar" on my classpath via: export CLASSPATH=$CLASSPATH:/home/me/ocpjp/chapter-10/mysql-connector-java-5.1.25/mysql-connector-java-5.1.25-bin.jar
- I am able to connect to mysql with "mysql -uroot -ptcial addressBook", if it matters.
- have also tried running with '-cp' argument with no avail.
- I am able to get my #3 DbConnect.java class to say "Database connection established".
- Also #4 DbQueryWorking.java has no issues and provides expected output .
Can you please help me understand what is the issue here ?
1) DbConnector.java
package com.me.ocpjp.chapter10;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class DbConnector{
public static Connection connectToDb() throws SQLException{
String url = "jdbc:mysql//localhost:3306/";
String db = "addressBook";
String username = "root";
String password = "tcial";
return DriverManager.getConnection(url+db, username, password);
}
}
2) DbQuery.java
package com.me.ocpjp.chapter10;
import java.sql.Connection ;
import java.sql.Statement ;
import java.sql.ResultSet ;
import java.sql.SQLException ;
import com.me.ocpjp.chapter10.DbConnector;
public class DbQuery{
public static void main(String[] args){
try(Connection connection = DbConnector.connectToDb();
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery("select * from contact")){
System.out.println("ID \tfName \tlName \temail \t\tphoneNo");
while(resultSet.next()){
System.out.println(resultSet.getInt("id") + "\t"
+ resultSet.getString("firstName") + "\t"
+ resultSet.getString("lastName") + "\t"
+ resultSet.getString("email") + "\t"
+ resultSet.getString("phoneNo") );
}
}catch(SQLException sqle){
sqle.printStackTrace();
System.exit(-1);
}
}
}
3) DbConnect.java
package com.me.ocpjp.chapter10;
import java.sql.Connection;
import java.sql.DriverManager;
public class DbConnect{
public static void main(String[] args){
String url = "jdbc:mysql://localhost:3306/";
String database = "addressBook";
String userName = "root";
String password = "tcial";
try(Connection connection = DriverManager.getConnection(url+database, userName, password)){
System.out.println("Database connection established");
}catch(Exception e){
System.out.println("Database connectioni NOT established");
e.printStackTrace();
}
}
}
4) DbQueryWorking.java
package com.me.ocpjp.chapter10;
import java.sql.Connection ;
import java.sql.Statement ;
import java.sql.ResultSet ;
import java.sql.SQLException ;
import java.sql.DriverManager;
public class DbQuery{
public static void main(String[] args){
String url = "jdbc:mysql://localhost:3306/";
String database = "addressBook";
String userName = "root";
String password = "tcial";
try(Connection connection = DriverManager.getConnection(url + database, userName, password);
Statement statement = connection.createStatement();
ResultSet resultSet = statement.executeQuery("select * from contact")){
System.out.println("ID \tfName \tlName \temail \t\tphoneNo");
while(resultSet.next()){
System.out.println(resultSet.getInt("id") + "\t"
+ resultSet.getString("firstName") + "\t"
+ resultSet.getString("lastName") + "\t"
+ resultSet.getString("email") + "\t"
+ resultSet.getString("phoneNo") );
}
}catch(SQLException sqle){
sqle.printStackTrace();
System.exit(-1);
}
}
}