Activiti工作流--分布式实现方案

 1 public interface ProcessEngine extends EngineServices {
 2 
 3   /** the version of the activiti library */
 4   public static String VERSION = "5.20.0.1";
 5 
 6   /** The name as specified in ‘process-engine-name‘ in 
 7    * the activiti.cfg.xml configuration file.
 8    * The default name for a process engine is ‘default */
 9   String getName();
10 
11   void close();
12 }

 1 /**
 2  * generates {@link IdBlock}s that are used to assign ids to new objects.
 3  * 
 4  * The scope of an instance of this class is process engine,
 5  * which means that there is only one instance in one process engine instance.
 6  * 
 7  * @author Tom Baeyens
 8  * @author Joram Barrez
 9  */
10 public interface IdGenerator {
11 
12   String getNextId();
13 
14 }

 1 /**
 2  * @author Tom Baeyens
 3  */
 4 public class DbIdGenerator implements IdGenerator {
 5 
 6   protected int idBlockSize;
 7   protected long nextId = 0;
 8   protected long lastId = -1;
 9   
10   protected CommandExecutor commandExecutor;
11   protected CommandConfig commandConfig;
12   
13   public synchronized String getNextId() {
14     if (lastId<nextId) {
15       getNewBlock();
16     }
17     long _nextId = nextId++;
18     return Long.toString(_nextId);
19   }
20 
21   protected synchronized void getNewBlock() {
22     IdBlock idBlock = commandExecutor.execute(commandConfig, new GetNextIdBlockCmd(idBlockSize));
23     this.nextId = idBlock.getNextId();
24     this.lastId = idBlock.getLastId();
25   }

 1 /**
 2  * @author Tom Baeyens
 3  */
 4 public class GetNextIdBlockCmd implements Command<IdBlock> {
 5   
 6   private static final long serialVersionUID = 1L;
 7   protected int idBlockSize;
 8   
 9   public GetNextIdBlockCmd(int idBlockSize) {
10     this.idBlockSize = idBlockSize;
11   }
12 
13   public IdBlock execute(CommandContext commandContext) {
14     PropertyEntity property = (PropertyEntity) commandContext
15       .getPropertyEntityManager()
16       .findPropertyById("next.dbid");
17     long oldValue = Long.parseLong(property.getValue());
18     long newValue = oldValue+idBlockSize;
19     property.setValue(Long.toString(newValue));
20     return new IdBlock(oldValue, newValue-1);
21   }
22 }

 1 /**
 2  * 分布式id生成器
 3  * 
 4  * @version 1.0
 5  * @author Pin Xiong
 6  * @date 创建时间：2016年8月12日 下午3:22:09
 7  */
 8 public class DistributedIdGenerator implements IdGenerator {
 9 
10     public DistributedIdGenerator(RedisService redisService) {
11         this.redisService = redisService;
12     }
13 
14     private RedisService redisService;
15 
16     @Override
17     public String getNextId() {
18         return String.format("%sX%s", D.formatDate(Constants.ACTIVITI_ENGINE_DISTRIBUTED_ID_PREFIX),this.redisService.incrby(Constants.ACTIVITI_ENGINE_DISTRIBUTED_ID_KEY, 1L));
20     }
21 }