Netbeans：如何以编程方式启动Derby数据库

Question

I have developed a Java project in Netbeans. Now I have the problem that the following code is only executeable if i start the specified database first:

private boolean DriverIsLoaded()
{
    try
    {
        Class.forName("org.apache.derby.jdbc.ClientDriver");
        return true;
    }
    catch(ClassNotFoundException e)
    {
        e.printStackTrace();
        return false;
    }
}
private boolean openConnectionAndCheck()
{
    try
    {
         connection = DriverManager.getConnection("jdbc:derby://localhost:1527/myDatabase;create=true", "Administrator", "Administrator");
         return true;
    }
    catch(SQLException e)
    {
        e.printStackTrace();
        return false;
    }
}

The I have created the database inside of Netbeans. My question is, how can I start the jdbc Database programatically?

Answer 1

The whole point of the Derby client-server configuration (ie, using the Derby ClientDriver and specifying a JDBC Connection URL of the form jdbc:derby://host:port/path/to/database ) is that the client and server are operated independently, typically on different computers, and typically there are multiple clients, but only a single server.

That is, the notion that the client will "start the jdbc Database programmatically" is not the expected behavior for this sort of configuration; the client and server aren't even on the same computer!

Perhaps what you want is the Derby "embedded" configuration.

Read more about the types of Derby deployment configurations here: http://db.apache.org/derby/docs/10.14/getstart/cgstutorialintro.html

And perhaps what you are really looking for is information about how to deploy, configure, and operate the Derby Network Server, for which start here: http://db.apache.org/derby/docs/10.14/adminguide/index.html

Answer 2

You are looking for programming Derby in embedded mode . Here is a code snippet:

package com.zetcode;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;

public class CreateCars {

    public static void main(String[] args) {

        Connection con = null;
        Statement st = null;

        String url = "jdbc:derby:testdb;user=USER12";

        try {

            System.setProperty("derby.system.home", "/home/janbodnar/.derby");

            con = DriverManager.getConnection(url);
            st = con.createStatement();
            st.executeUpdate("CREATE TABLE CARS(ID INT PRIMARY KEY,"
                    + "NAME VARCHAR(30), PRICE INT)");
            st.executeUpdate("INSERT INTO CARS VALUES(1, 'Audi', 52642)");
            st.executeUpdate("INSERT INTO CARS VALUES(2, 'Mercedes', 57127)");
            st.executeUpdate("INSERT INTO CARS VALUES(3, 'Skoda', 9000)");
            st.executeUpdate("INSERT INTO CARS VALUES(4, 'Volvo', 29000)");
            st.executeUpdate("INSERT INTO CARS VALUES(5, 'Bentley', 350000)");
            st.executeUpdate("INSERT INTO CARS VALUES(6, 'Citroen', 21000)");
            st.executeUpdate("INSERT INTO CARS VALUES(7, 'Hummer', 41400)");
            st.executeUpdate("INSERT INTO CARS VALUES(8, 'Volkswagen', 21600)");
            DriverManager.getConnection("jdbc:derby:;shutdown=true");

        } catch (SQLException ex) {

            Logger lgr = Logger.getLogger(CreateCars.class.getName());

            if (((ex.getErrorCode() == 50000)
                    && ("XJ015".equals(ex.getSQLState())))) {

                lgr.log(Level.INFO, "Derby shut down normally", ex);

            } else {

                lgr.log(Level.SEVERE, ex.getMessage(), ex);
            }

        } finally {

            try {

                if (st != null) {
                    st.close();
                }
                if (con != null) {
                    con.close();
                }

            } catch (SQLException ex) {
                Logger lgr = Logger.getLogger(CreateCars.class.getName());
                lgr.log(Level.WARNING, ex.getMessage(), ex);
            }
        }
    }
}

For a full tutorial, have a look at my Programming Derby with JDBC tutorial.