CheckJDBCInstallation_MySQL.java Source code

Introduction

Here is the source code for CheckJDBCInstallation_MySQL.java

Source

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

public class CheckJDBCInstallation_MySQL {
    public static Connection getConnection() throws Exception {
        String driver = "org.gjt.mm.mysql.Driver";
        String url = "jdbc:mysql://localhost/databaseName";
        String username = "root";
        String password = "root";
        Class.forName(driver); // load MySQL driver
        Connection conn = DriverManager.getConnection(url, username, password);
        return conn;
    }

    /**
     * Test Validity of JDBC Installation
     * 
     * @param conn
     *          a JDBC connection object
     * @return true if a given connection object is a valid one; otherwise return
     *         false.
     * @throws Exception
     *           Failed to determine if a given connection is valid.
     */
    public static boolean isValidConnection(Connection conn) throws Exception {
        if (conn == null) {
            // null connection object is not valid
            return false;
        }

        if (conn.isClosed()) {
            // closed connection object is not valid
            return false;
        }

        // for MySQL database:
        // you may use the connection object
        // with query of "select 1"; if the
        // query returns the result, then it
        // is a valid connection object.
        return testConnection(conn, "select 1");
    }

    /**
     * Test Validity of a Connection
     * 
     * @param conn
     *          a JDBC connection object
     * @param query
     *          a sql query to test against database connection
     * @return true if a given connection object is a valid one; otherwise return
     *         false.
     */
    public static boolean testConnection(Connection conn, String query) {

        ResultSet rs = null;
        Statement stmt = null;
        try {
            stmt = conn.createStatement();
            if (stmt == null) {
                return false;
            }

            rs = stmt.executeQuery(query);
            if (rs == null) {
                return false;
            }

            if (rs.next()) {
                // connection object is valid: we were able to
                // connect to the database and return something useful.
                return true;
            }

            // there is no hope any more for the validity
            // of the connection object
            return false;

        } catch (Exception e) {
            //
            // something went wrong: connection is bad
            //
            return false;
        } finally {
            try {
                rs.close();
                stmt.close();
                conn.close();
            } catch (Exception e) {
            }
        }
    }

    public static void main(String[] args) {

        Connection conn = null;
        try {
            conn = getConnection();
            System.out.println("conn=" + conn);
            System.out.println("valid connection = " + isValidConnection(conn));
        } catch (Exception e) {
            // handle the exception
            e.printStackTrace();
            System.exit(1);
        } finally {
            // release database resources
            try {
                conn.close();
            } catch (Exception e) {
            }
        }
    }
}