GlueSequence 개발 예

다음은 sequence incrementer를 지원하지 않는 Phoenix 을 사용하는 경우의 예시입니다.

1. applicationContext.xml : dao 의 sequence 설정

   <beans ...>
       <bean id="dao" class="com.poscoict.glueframework.dao.jdbc.GlueJdbcDao">
           <property name="dataSource"><ref local="dataSource"/></property>
           <property name="queryManager"><ref local="queryManager"/></property>
           <property name="sequence"><ref local="sequence"/></property>
       </bean>
       <bean id="sequence" class="PhoenixSequence">
           <constructor-arg><ref local="dataSource"/></constructor-arg>
       </bean>
       <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
           <property name="driverClassName" value="org.apache.phoenix.jdbc.PhoenixDriver"/>
           <property name="url" value="jdbc:phoenix:0.0.0.0:2181"/>  
       </bean>
   </beans>
   

2. GlueSequence 구현

   import java.sql.Connection;
   import java.sql.ResultSet;
   import java.sql.SQLException;
   import java.sql.Statement;
   
   import javax.sql.DataSource;
   
   import org.springframework.dao.DataAccessException;
   import org.springframework.dao.DataAccessResourceFailureException;
   import org.springframework.jdbc.datasource.DataSourceUtils;
   import org.springframework.jdbc.support.JdbcUtils;
   
   public class PhoenixSequence implements GlueSequence
   {
       private DataSource dataSource;
   
       public GluePhoenixSequence( DataSource ds )
       {
           this.dataSource = ds;
       }
   
       public DataSource getDataSource()
       {
           return this.dataSource;
       }
   
       @Override
       public long getNextLongValue( String sequenceName )
       {
           return getNextKey( sequenceName );
       }
   
       @Override
       public int getNextIntValue( String sequenceName )
       {
           return (int) getNextKey( sequenceName );
       }
   
       @Override
       public String getNextStringValue( String sequenceName )
       {
           return Long.toString( getNextKey( sequenceName ) );
       }
   
       private String getSequenceQuery( String sequenceName )
       {
           return "select NEXT VALUE FOR " + sequenceName + " from SYSTEM.\"SEQUENCE\" limit 1";
       }
   
       private long getNextKey( String sequenceName ) throws DataAccessException
       {
           Connection con = DataSourceUtils.getConnection( getDataSource() );
           Statement stmt = null;
           ResultSet rs = null;
           try
           {
               stmt = con.createStatement();
               DataSourceUtils.applyTransactionTimeout( stmt, getDataSource() );
               rs = stmt.executeQuery( this.getSequenceQuery( sequenceName ) );
               if ( rs.next() )
               {
                   return rs.getLong( 1 );
               } else
               {
                   throw new DataAccessResourceFailureException( "Sequence query did not return a result" );
               }
           } catch ( SQLException ex )
           {
               throw new DataAccessResourceFailureException( "Could not obtain sequence value", ex );
           } finally
           {
               JdbcUtils.closeResultSet( rs );
               JdbcUtils.closeStatement( stmt );
               DataSourceUtils.releaseConnection( con, getDataSource() );
           }
       }
   }