H2 JDBC Example

H2JDBC

package com.volnoboy;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class H2JDBC {

        //To start h2 server uncomment next two lines:
        //String arguments[] = {"-tcpAllowOthers", "-tcpPort", "9092"};
        //Server server = Server.createTcpServer(arguments).start();

    // JDBC driver name and database URL
    static final String JDBC_DRIVER = "org.h2.Driver";
    static final String DB_URL = "jdbc:h2:~/test";

    //  Database credentials
    static final String USER = "sa";
    static final String PASS = "sa";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try{
            //STEP 2: Register JDBC driver
            Class.forName(JDBC_DRIVER);

            //STEP 3: Open a connection
            System.out.println("Connecting to database...");
            conn = DriverManager.getConnection(DB_URL, USER, PASS);


            //STEP 4: Execute a query
            System.out.println("Creating statement...");
            stmt = conn.createStatement();
            String sql = "Select * from persons";
            ResultSet rs = stmt.executeQuery(sql);

            //STEP 5: Extract data from result set
            while(rs.next()){
                //Retrieve by column name
                String address  = rs.getString("address");
                String city  = rs.getString("city");

                //Display values
                System.out.print("ADDRESS: " + address);
                System.out.print(", CITY: " + city);
            }
            //To start h2 web console uncomment next line:
            //org.h2.tools.Server.startWebServer(conn);
            //STEP 6: Clean-up environment
            rs.close();
            stmt.close();
            conn.close();
        }catch(SQLException se){
            //Handle errors for JDBC
            se.printStackTrace();
        }catch(Exception e){
            //Handle errors for Class.forName
            e.printStackTrace();
        }finally{
            //finally block used to close resources
            try{
                if(stmt!=null)
                    stmt.close();
            }catch(SQLException se2){
            }// nothing we can do
            try{
                if(conn!=null)
                    conn.close();
            }catch(SQLException se){
                se.printStackTrace();
            }//end finally try
        }//end try
        System.out.println("Goodbye!");
    }//end main


}