Bellek içi Apache Derby

Question

bir Gömülü Server'ı başlatmak için nasıl (yani. Sürece uygulama çevrimiçi olduğu gibi sadece çevrimiçi bir veritabanı sunucusu) Ayrıca

iyi bir örnek var mı kullanan sunucu gömülü, bu mümkün sadece bellek içi olması için?

Answer 1

İndir Apache Derby ve aşağıdaki dosyaları projenizde başvuruları ekleyin:

derby.jar 
derbynet.jar 
derbyclient.jar 

Kullanım sunucusunu başlatmak ve bellek içi veritabanı oluşturmak için aşağıdaki kodu:

import java.net.InetAddress; 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.SQLNonTransientConnectionException; 
import java.util.ArrayList; 
import java.util.List; 
import org.apache.derby.drda.NetworkServerControl; 

public class DerbyInMemoryEmbeddedServer { 

    public static void main(String[] args) throws Exception { 
     NetworkServerControl server = new NetworkServerControl(InetAddress.getByName("localhost"), 1528); 
     server.start(null); 

     String connectionString = "jdbc:derby://localhost:1528/memory:hello_world_database;create=true"; 
     Connection conn = DriverManager.getConnection(connectionString); 
     System.out.println("Server started"); 

     //create the database here. The following is an example: 

     //create the users table 
     try (PreparedStatement ps = conn.prepareStatement(
       "create table users (" 
       + "id int not null generated always as identity, " 
       + "username varchar(8000), " 
       + "first_name varchar(8000), " 
       + "surname varchar(8000), " 
       + "primary key (id), " 
       + "constraint uc_username unique (username)" 
       + ")")) { 
      ps.execute(); 
     } 

     //create an index 
     try (PreparedStatement ps = conn.prepareStatement(
       "create index ix_surname on users (surname)")) { 
      ps.execute(); 
     } 

     //add some users 
     List<String> names = new ArrayList<>(); 
     names.add("jhuff|Jeffrey|Huffines"); 
     names.add("woodsey223|Sherwood|Gurule"); 
     names.add("tim_w|Tim|Woods"); 
     try (PreparedStatement ps = conn.prepareStatement("insert into users (username, first_name, surname) values (?, ?, ?)")) { 

      for (String name : names) { 
       String[] tokens = name.split("\\|"); 

       ps.setString(1, tokens[0]); 
       ps.setString(2, tokens[1]); 
       ps.setString(3, tokens[2]); 
       ps.addBatch(); 
      } 

      ps.executeBatch(); 
     } 

     //create the team table 
     try (PreparedStatement ps = conn.prepareStatement(
       "create table team (" 
       + "id int not null generated always as identity, " 
       + "name varchar(8000), " 
       + "primary key (id)," 
       + "constraint uc_team_name unique (name)" 
       + ")")) { 
      ps.execute(); 
     } 

     //insert a team 
     try (PreparedStatement ps = conn.prepareStatement(
       "insert into team (name) values (?)")) { 
      ps.setString(1, "Wombats"); 
      ps.executeUpdate(); 
     } 

     //create a many-to-many table to link teams to users. (Since a user can belong to more than one team) 
     try (PreparedStatement ps = conn.prepareStatement(
       "create table team_member (" 
       + "id int not null generated always as identity, " 
       + "team_id int not null, " 
       + "user_id int not null," 
       + "constraint fk_team_member_team foreign key (team_id) references team(id), " 
       + "constraint fl_team_member_user foreign key (user_id) references users(id), " 
       + "primary key (id)" 
       + ")")) { 
      ps.execute(); 
     } 

     //create team members 
     List<String> teamMembers = new ArrayList<>(); 
     teamMembers.add("jhuff|Wombats"); 
     teamMembers.add("tim_w|Wombats"); 

     try (PreparedStatement ps = conn.prepareStatement("insert into team_member (team_id, user_id) values (" 
       + "(select id from team where name = ?)," 
       + "(select id from users where username = ?)" 
       + ")")) { 

      for (String teamMember : teamMembers) { 
       String[] tokens = teamMember.split("\\|"); 

       ps.setString(1, tokens[1]); 
       ps.setString(2, tokens[0]); 
       ps.addBatch(); 
      } 
      ps.executeBatch(); 
     } 

     System.out.println("Server ready"); 
     System.in.read(); 

     System.out.println("Disconnecting"); 
     String shutdownConnectionString = connectionString + ";shutdown=true"; 

     try { 
      DriverManager.getConnection(shutdownConnectionString); 
     } catch (SQLNonTransientConnectionException ex) { 
      //derby throws an exception on disconnection 
     } 

     System.out.println("Disconnected"); 
    } 
} 

Eğer sonunda veritabanınızın uygulama yeniden başlatmaları arasında kalmasını istiyorsanız, bunun yerine bu bağlantı dizesini kullanın:

jdbc:derby://localhost:1528/jdbc:derby:C:\db_files\proof_of_concept;create=true;