com.shigengyu.hyperion.core.WorkflowInstance.java Source code

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/*******************************************************************************
 * Copyright 2013-2014 Gengyu Shi
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.shigengyu.hyperion.core;

import java.io.IOException;

import javax.annotation.Resource;

import org.apache.commons.io.IOUtils;
import org.springframework.stereotype.Service;

import com.google.common.base.Function;
import com.google.common.collect.Lists;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.nio.serialization.DataSerializable;
import com.shigengyu.hyperion.entities.WorkflowInstanceEntity;
import com.shigengyu.hyperion.entities.WorkflowStateEntity;

public class WorkflowInstance implements DataSerializable {

    @Service
    public static class WorkflowInstanceFactory {

        @Resource
        private WorkflowContextSerializer workflowContextSerializer;

        public WorkflowInstance create(WorkflowDefinition workflowDefinition) {

            WorkflowInstance workflowInstance = new WorkflowInstance(workflowDefinition);
            workflowInstance.workflowContextSerializer = workflowContextSerializer;
            return workflowInstance;
        }

        public WorkflowInstance create(WorkflowDefinition workflowDefinition, WorkflowInstanceEntity entity) {

            WorkflowInstance workflowInstance = new WorkflowInstance(workflowDefinition, entity);
            workflowInstance.workflowContextSerializer = workflowContextSerializer;
            workflowInstance.workflowContext = WorkflowContextSerializers.get()
                    .deserialize(workflowDefinition.getWorkflowContextType(), entity.getWorkflowContext());
            return workflowInstance;
        }
    }

    private WorkflowContextSerializer workflowContextSerializer;

    private final TransitionParameterSet parameters = TransitionParameterSet.create();

    private WorkflowDefinition workflowDefinition;

    private int workflowInstanceId;

    private WorkflowStateSet workflowStateSet;

    private WorkflowContext workflowContext;

    private WorkflowInstance() {
    }

    /**
     * Creates a new workflow instance with the specified workflow definition
     * 
     * @param workflowDefinition
     */
    private WorkflowInstance(WorkflowDefinition workflowDefinition) {
        this.workflowDefinition = workflowDefinition;
        workflowStateSet = WorkflowStateSet.from(workflowDefinition.getInitialState());
        try {
            workflowContext = workflowDefinition.getWorkflowContextType().newInstance();
        } catch (Exception e) {
            throw new WorkflowContextException("Failed to create new workflow context of type ["
                    + workflowDefinition.getWorkflowContextType().getName() + "]");
        }
    }

    /**
     * Create a {@link WorkflowInstance} object from an existing workflow instance
     * 
     * @param workflowDefinition
     * @param entity
     */
    private WorkflowInstance(WorkflowDefinition workflowDefinition, WorkflowInstanceEntity entity) {
        this(workflowDefinition);

        workflowInstanceId = entity.getWorkflowInstanceId();

        workflowStateSet = WorkflowStateSet.from(
                Lists.transform(entity.getWorkflowStateEntities(), new Function<WorkflowStateEntity, String>() {

                    @Override
                    public String apply(WorkflowStateEntity input) {
                        return input.getWorkflowStateId();
                    }
                }));
    }

    private WorkflowInstance(WorkflowInstance workflowInstance) {
        workflowInstanceId = workflowInstance.workflowInstanceId;
        workflowDefinition = workflowInstance.workflowDefinition;
        workflowStateSet = WorkflowStateSet.from(workflowInstance.workflowStateSet);
    }

    @Override
    public WorkflowInstance clone() {
        WorkflowInstance workflowInstance = new WorkflowInstance(this);
        return workflowInstance;
    }

    public String debugString() {
        return "Workflow Instance <" + workflowDefinition.getName() + ">" + IOUtils.LINE_SEPARATOR + "ID = "
                + workflowInstanceId + IOUtils.LINE_SEPARATOR + "State = " + workflowStateSet;
    }

    public <T> T getParameter(final Class<T> clazz, String name) {
        return parameters.get(clazz, name);
    }

    public final <T extends WorkflowContext> T getWorkflowContext() {
        return (T) workflowDefinition.getWorkflowContextType().cast(workflowContext);
    }

    public WorkflowDefinition getWorkflowDefinition() {
        return workflowDefinition;
    }

    public int getWorkflowInstanceId() {
        return workflowInstanceId;
    }

    public WorkflowStateSet getWorkflowStateSet() {
        return workflowStateSet;
    }

    @Override
    public void readData(ObjectDataInput in) throws IOException {
        workflowInstanceId = in.readInt();
        workflowDefinition = in.readObject();
        workflowStateSet = in.readObject();
        workflowContext = WorkflowContextSerializers.get().deserialize(workflowDefinition.getWorkflowContextType(),
                in.readUTF());
    }

    public void restoreFrom(WorkflowInstance workflowInstance) {
        workflowInstanceId = workflowInstance.workflowInstanceId;
        workflowDefinition = workflowInstance.workflowDefinition;
        workflowStateSet = workflowInstance.workflowStateSet;
    }

    public <T> WorkflowInstance setParameter(String name, T value) {
        parameters.set(name, value);
        return this;
    }

    public void setWorkflowDefinition(WorkflowDefinition workflowDefinition) {
        this.workflowDefinition = workflowDefinition;
    }

    public void setWorkflowInstanceId(int workflowInstanceId) {
        this.workflowInstanceId = workflowInstanceId;
    }

    public void setWorkflowStateSet(WorkflowStateSet workflowStateSet) {
        this.workflowStateSet = workflowStateSet;
    }

    public WorkflowInstanceEntity toEntity() {
        WorkflowInstanceEntity entity = new WorkflowInstanceEntity();
        entity.setWorkflowDefinitionEntity(workflowDefinition.toEntity());
        entity.setWorkflowInstanceId(workflowInstanceId);
        entity.setWorkflowStateEntities(workflowStateSet.toEntityList());
        entity.setWorkflowContext(WorkflowContextSerializers.get().serialize(workflowContext));
        return entity;
    }

    @Override
    public String toString() {
        return "<" + workflowDefinition.getName() + "> (" + workflowInstanceId + ")";
    }

    @Override
    public void writeData(ObjectDataOutput out) throws IOException {
        out.writeInt(workflowInstanceId);
        out.writeObject(workflowDefinition);
        out.writeObject(workflowStateSet);
        out.writeUTF(WorkflowContextSerializers.get().serialize(workflowContext));
    }
}