/*
 * # How to use this script
 * 0. Place Redshift JDBC driver onto the local directory
 *   $ ls -al ./RedshiftJDBC42-1.2.10.1009.jar
 * 1. Compile
 *   $ javac connection/Connect.java
 * 2. Execute
 *   $ java -classpath .:RedshiftJDBC42-1.2.10.1009.jar connection.Connect
 */

package connection;

import java.sql.*;
import java.util.Properties;

public class Connect {
    // Redshift driver: "jdbc:redshift://x.y.us-west-2.redshift.amazonaws.com:5439/dev";
    // or "jdbc:postgresql://x.y.us-west-2.redshift.amazonaws.com:5439/dev";
    static final String dbURL = "***jdbc cluster connection string ****";
    static final String MasterUsername = "***master user name***";
    static final String MasterUserPassword = "***master user password***";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try{
           //Dynamically load driver at runtime.
           //Redshift JDBC 4.1 driver: com.amazon.redshift.jdbc41.Driver
           //Redshift JDBC 4 driver: com.amazon.redshift.jdbc4.Driver
           Class.forName("com.amazon.redshift.jdbc.Driver");

           //Open a connection and define properties.
           System.out.println("Connecting to database...");
           Properties props = new Properties();

           //Uncomment the following line if using a keystore.
           //props.setProperty("ssl", "true");
           props.setProperty("user", MasterUsername);
           props.setProperty("password", MasterUserPassword);
           conn = DriverManager.getConnection(dbURL, props);

           //Try a simple query.
           System.out.println("Listing system tables...");
           stmt = conn.createStatement();
           String sql;
           sql = "select * from information_schema.tables;";
           ResultSet rs = stmt.executeQuery(sql);

           //Get the data from the result set.
           while(rs.next()){
              //Retrieve two columns.
              String catalog = rs.getString("table_catalog");
              String name = rs.getString("table_name");

              //Display values.
              System.out.print("Catalog: " + catalog);
              System.out.println(", Name: " + name);
           }
           rs.close();
           stmt.close();
           conn.close();
        }catch(Exception ex){
           //For convenience, handle all errors here.
           ex.printStackTrace();
        }finally{
           //Finally block to close resources.
           try{
              if(stmt!=null)
                 stmt.close();
           }catch(Exception ex){
           }// nothing we can do
           try{
              if(conn!=null)
                 conn.close();
           }catch(Exception ex){
              ex.printStackTrace();
           }
        }
        System.out.println("Finished connectivity test.");
     }
}