【整合篇】Activiti业务与流程整合之查询（二）

继上篇博客：【整合篇】JBPM4.4业务与流程整合之查询 应用第二种方式：申请实体中加入需要的相应的工作流的属性

package com.tgb.itoo.basic.entity;

import java.util.Date;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.Transient;

import org.activiti.engine.history.HistoricProcessInstance;
import org.activiti.engine.repository.ProcessDefinition;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.task.Task;
import org.codehaus.jackson.annotate.JsonIgnore;
import org.springframework.format.annotation.DateTimeFormat;

/**
 * Entity: Leave
 *
 * @author hejingyuan IdEntity implements Serializable
 */
@Entity
@Table(name = "OA_LEAVE")
public class Leave  extends IdEntity { 

    /**
 * 
 */
private static final long serialVersiOnUID= 1L;
private String processInstanceId;
    private String userId;
    private String testId;
    private String oldCourse;
    private String applyCourse;
    @Column
    public String getApplyCourse() {
return applyCourse;
}

public void setApplyCourse(String applyCourse) {
this.applyCourse = applyCourse;
}

@Column
    public String getOldCourse() {
return oldCourse;
}

public void setOldCourse(String oldCourse) {
this.oldCourse = oldCourse;
}
@Column
public String getNewCourse() {
return newCourse;
}

public void setNewCourse(String newCourse) {
this.newCourse = newCourse;
}

private String newCourse;
   
    @Column
    public String getTestId() {
return testId;
}

public void setTestId(String testId) {
this.testId = testId;
}

@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm")
    private Date startTime;

    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm")
    private Date endTime;

   /* @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm")
    private Date realityStartTime;

    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm")
    private Date realityEndTime;*/
    private Date applyTime;
    private String leaveType;
    private String reason;

    //-- 临时属性 --//

    // 流程任务
    private Task task;

    private Map variables;

    // 运行中的流程实例
    private ProcessInstance processInstance;

    // 历史的流程实例
    private HistoricProcessInstance historicProcessInstance;

    // 流程定义
    private ProcessDefinition processDefinition;

    @Column
    public String getProcessInstanceId() {
        return processInstanceId;
    }

    public void setProcessInstanceId(String processInstanceId) {
        this.processInstanceId = processInstanceId;
    }

    @Column
    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "START_TIME")
    public Date getStartTime() {
        return startTime;
    }

    public void setStartTime(Date startTime) {
        this.startTime = startTime;
    }

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "END_TIME")
    public Date getEndTime() {
        return endTime;
    }

    public void setEndTime(Date endTime) {
        this.endTime = endTime;
    }

    @Column
    @Temporal(TemporalType.TIMESTAMP)
    public Date getApplyTime() {
        return applyTime;
    }

    public void setApplyTime(Date applyTime) {
        this.applyTime = applyTime;
    }

    @Column
    public String getLeaveType() {
        return leaveType;
    }

    public void setLeaveType(String leaveType) {
        this.leaveType = leaveType;
    }

    @Column
    public String getReason() {
        return reason;
    }

    public void setReason(String reason) {
        this.reason = reason;
    }
   
    /**
 * 学生基础信息
 */
@ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER, targetEntity = StudentCourseInfo.class)
@JoinColumn(name = "studentCourseInfoId", nullable = true)
private StudentCourseInfo studentCourseInfo;

    public StudentCourseInfo getStudentCourseInfo() {
return studentCourseInfo;
}

public void setStudentCourseInfo(StudentCourseInfo studentCourseInfo) {
this.studentCourseInfo = studentCourseInfo;
}

@Transient
    public Task getTask() {
        return task;
    }

    public void setTask(Task task) {
        this.task = task;
    }

    @Transient
    public Map getVariables() {
        return variables;
    }

    public void setVariables(Map variables) {
        this.variables = variables;
    }

    @Transient
    public ProcessInstance getProcessInstance() {
        return processInstance;
    }

    public void setProcessInstance(ProcessInstance processInstance) {
        this.processInstance = processInstance;
    }

    @Transient
    public HistoricProcessInstance getHistoricProcessInstance() {
        return historicProcessInstance;
    }

    public void setHistoricProcessInstance(HistoricProcessInstance historicProcessInstance) {
        this.historicProcessInstance = historicProcessInstance;
    }

    @Transient
    public ProcessDefinition getProcessDefinition() {
        return processDefinition;
    }

    public void setProcessDefinition(ProcessDefinition processDefinition) {
        this.processDefinition = processDefinition;
    }


}

在真正应用之前我们先来简单介绍一下在Activiti中比JBPM4.4的一处优化。

在activiti中，它为我们提供了一个businessKey字段。

在启动流程时，流程实例中会添加一条记录，而且流程实例表中会有一个businessKey字段，String businessKey = leave.getId().toString();这样我们的流程表中就始终拥有业务的id，当我们再次需要的时候可以重新查询。

下面举例说明：

 /**
     * 任务列表ERROR [stderr] (http-localhost/127.0.0.1:8080-3) ScriptEngineManager providers.next(): javax.script.ScriptEngineFactory: Provider com.sun.script.Javascript.RhinoScriptEngineFactory not found
     *
     * @param leave
     */
    @RequestMapping(value = "list/task")
    public ModelAndView taskList(HttpSession session, HttpServletRequest request) {
    List results = new ArrayList();
    String userId = UserUtil.getUserFromSession(session).getId();
    results=abstractTaskList(userId);    
    return new ModelAndView("/oa/leave/taskList","results",results);                            
         
    }

/**
     * 抽象出来的查看任务列表，与基本业务无关
     *
     * @param userId 用户id
     * @return
     */
public List abstractTaskList(String userId){
 List results = new ArrayList();
     // 根据当前人的ID查询
     TaskQuery taskQuery = taskService.createTaskQuery().taskCandidateOrAssigned(userId);        
     List tasks = taskQuery.list();     
     int i=0;
     
     // 根据流程的业务ID查询实体并关联
     for (Task task : tasks) {
         String processInstanceId = task.getProcessInstanceId();
         ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceId(processInstanceId).active().singleResult();
         String businessKey = processInstance.getBusinessKey();
         if (businessKey == null) {
             continue;
         } 
         Leave leave=updateEntity(processInstance,task,businessKey);
         results.add(leave); 
         i=i+1;
     }
return results;
}

//更新实体 
   public Leave updateEntity(ProcessInstance processInstance,Task task,String businessKey){
   Leave leave = leaveBean.findEntityById(businessKey);
   leave.setProcessInstance(processInstance);
leave.setProcessDefinition(getProcessDefinition(processInstance.getProcessDefinitionId()));                
leave.setTask(task);
return leave;
   }

对比：

    之前的JBPM的操作方式，启动流程时将业务数据存储到流程变量中，在需要查询时，将数据从流程变量中取出，然后将取出的值赋给我们的组合实体即可。这样做的弊端在于数据可能会出现不同步的情况，但是应该并不多见。

    其实使用这种方式呢，即使在实体层添加了工作流的属性，但是并不需要在真正的数据库表中添加相应的字段，那么这样做的便利在哪里呢？其实这样做主要是使得我们在返回前台数据时更加方便，我们只需要返回一个实体即可。但是弊端是什么呢，就是业务的实体中需要知道一些工作流的属性。

    而且弊端不仅如此，在大型系统中，相当于实体层需要加入所有的依赖工作流的jar包，如果这个实体还需要被其他系统所依赖，那么所有的系统都会有工作流的依赖，我们曾遇到的问题就是，当我们在当前系统的实体项目中加入工作流的依赖时，由于其他系统也依赖我们本实体，导致所有的系统均瘫痪jboss不能正常启动，报不识别工作流的类。这种影响就是深远的，所以我们要实现的还是解耦。

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