databasefilemgr.java

一个java工作流引擎

package org.jbpm.persistence.filemgr;

import org.apache.commons.logging.*;
import org.jbpm.*;
import org.jbpm.model.definition.impl.*;
import org.jbpm.persistence.*;

public class DatabaseFileMgr implements FileMgr {

  protected PersistenceSessionFactory persistenceSessionFactory = null;
  
  public DatabaseFileMgr( JbpmConfiguration jbpmConfiguration ) {
    persistenceSessionFactory = (PersistenceSessionFactory) jbpmConfiguration.instantiate( "jbpm.persistence.session.factory", PersistenceSessionFactory.class );
  }

	public void storeBytes(Long definitionId, String fileName, byte[] bytes) {
    FileImpl file = new FileImpl( definitionId, fileName, bytes );
    
    PersistenceSessionTx sessionTx = null;
    try {
      log.info( "storing file '" + fileName + "' for definition '" + definitionId + "'..." );

      // get a persistence session with a transaction
      sessionTx = persistenceSessionFactory.createPersistenceSessionTx();

      // save all changes made in the process instance
      sessionTx.save( file );
      
      // commit the transaction
      sessionTx.commitAndClose();
      sessionTx = null;

      if ( log.isDebugEnabled() ) log.debug( "stored file '" + fileName + "' successfully" );
      
    } finally {
      if ( sessionTx != null ) {
        sessionTx.rollbackAndClose();
      }
    }
  }

	public byte[] retrieveBytes(Long definitionId, String fileName) {
    byte[] bytes = null;
    PersistenceSession session = null;
    try {
      if ( log.isDebugEnabled() ) log.info( "retrieving file '" + fileName + "' for definition '" + definitionId + "' from database..." );

      // get a persistence session with a transaction
      session = persistenceSessionFactory.createPersistenceSession();

      // save all changes made in the process instance
      FileImpl file = session.findFile( definitionId, fileName );
      if ( file != null ) {
        bytes = file.getBytes();
      }
      
      if ( log.isDebugEnabled() ) log.debug( "retrieved file '" + fileName + "' successfully" );
      
    } finally {
      if ( session != null ) {
        session.close();
      }
    }
		return bytes;
	}

  private static Log log = LogFactory.getLog(DatabaseFileMgr.class);
}