这篇文章主要讲解了“如何配置工作流引擎Activiti集成JPA持久化保存流程数据”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“如何配置工作流引擎Activiti集成JPA持久化保存流程数据”吧！
Activiti中JPA简介
可以使用JPA实体作为流程变量, 并进行操作:
基于流程变量更新已有的JPA实体,可以在用户任务的表单中填写或者由服务任务生成
重用已有的领域模型,不需要编写显示的服务获取实体或者更新实体的值
根据已有实体的属性做出判断(网关即分支聚合)
JPA实体要求
JPA配置
引擎必须有一个对EntityManagerFactory的引用才能够使用JPA的实体,这样可以通过配置引用或者提供一个持久化单元名称
作为变量的JPA实体将会被自动检测并进行相应的处理
使用jpaPersistenceUnitName配置:
<bean id="processEngineConfiguration" class="org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration">
<!-- 数据库的配置 -->
<property name="databaseSchemaUpdate" value="true" />
<property name="jdbcUrl" value="jdbc:h3:mem:JpaVariableTest;DB_CLOSE_DELAY=1000" />
<property name="jpaPersistenceUnitName" value="activiti-jpa-pu" />
<property name="jpaHandleTransaction" value="true" />
<property name="jpaCloseEntityManager" value="true" />
<!-- job executor configurations -->
<property name="jobExecutorActivate" value="false" />
<!-- mail server configurations -->
<property name="mailServerPort" value="5025" />
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitManager" ref="pum"/>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.OpenJpaVendorAdapter">
<property name="databasePlatform" value="org.apache.openjpa.jdbc.sql.H2Dictionary" />
</bean>
</property>
</bean>
<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
<property name="dataSource" ref="dataSource" />
<property name="transactionManager" ref="transactionManager" />
<property name="databaseSchemaUpdate" value="true" />
<property name="jpaEntityManagerFactory" ref="entityManagerFactory" />
<property name="jpaHandleTransaction" value="true" />
<property name="jpaCloseEntityManager" value="true" />
<property name="jobExecutorActivate" value="false" />
</bean>
ProcessEngine processEngine = ProcessEngineConfiguration
.createProcessEngineConfigurationFromResourceDefault()
.setJpaPersistenceUnitName("activiti-pu")
.buildProcessEngine();配置的属性有:
jpaPersistenceUnitName: 使用持久化单元的名称:
要确保该持久化单元在类路径下是可用的,默认的路径是 /META-INF/persistence.xml
要么使用jpaEntityManagerFactory要么或者是jpaPersistenceUnitName
jpaEntityManagerFactory: 一个实现了javax.persistence.EntityManagerFactory的bean的引用:
jpaHandleTransaction: 在被使用的EntityManager实例上,该标记表示流程引擎是否需要开始和提交或者回滚事务:
jpaCloseEntityManager: 该标记表示流程引擎是否应该关闭从 EntityManagerFactory获取的EntityManager的实例:
JPA用法
简单示例
首先,需要创建一个基于META-INF/persistence.xml的EntityManagerFactory作为持久化单元:包含持久化单元中所有的类和一些供应商特定的配置
使用一个简单的实体作为测试,其中包含有一个id和String类型的value属性,也将会被持久化
在测试之前,创建一个实体并且保存:
@Entity(name = "JPA_ENTITY_FIELD")
public class FieldAccessJPAEntity {
@Id
@Column(name = "ID_")
private Long id;
private String value;
public FieldAccessJPAEntity() {
// Empty constructor needed for JPA
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}Map<String, Object> variables = new HashMap<String, Object>();
variables.put("entityToUpdate", entityToUpdate);
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("UpdateJPAValuesProcess", variables);<serviceTask id='theTask' name='updateJPAEntityTask' activiti:expression="${entityToUpdate.setValue('updatedValue')}" />// Servicetask in process 'UpdateJPAValuesProcess' should have set value on entityToUpdate.
Object updatedEntity = runtimeService.getVariable(processInstance.getId(), "entityToUpdate");
assertTrue(updatedEntity instanceof FieldAccessJPAEntity);
assertEquals("updatedValue", ((FieldAccessJPAEntity)updatedEntity).getValue())查询JPA流程变量
以查询某一JPA实体作为变量的ProcessInstances和Executions
在ProcessInstanceQuery和ExecutionQuery查询中仅仅variableValueEquals(name, entity) 支持JPA实体变量:
[variableValueNotEquals],[variableValueGreaterThan],[variableValueGreaterThanOrEqual],[variableValueLessThan],[variableValueLessThanOrEqual]不被支持并且传递JPA实体值的时候会抛出一个ActivitiException
ProcessInstance result = runtimeService.createProcessInstanceQuery().variableValueEquals("entityToQuery", entityToQuery).singleResult();使用Spring beans和JPA结合的高级例子
<?xml version="1.0" encoding="UTF-8"?>
<definitions id="taskAssigneeExample"
xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:activiti="http://activiti.org/bpmn"
targetNamespace="org.activiti.examples">
<process id="LoanRequestProcess" name="Process creating and handling loan request">
<startEvent id='theStart' />
<sequenceFlow id='flow1' sourceRef='theStart' targetRef='createLoanRequest' />
<serviceTask id='createLoanRequest' name='Create loan request'
activiti:expression="${loanRequestBean.newLoanRequest(customerName, amount)}"
activiti:resultVariable="loanRequest"/>
<sequenceFlow id='flow2' sourceRef='createLoanRequest' targetRef='approveTask' />
<userTask id="approveTask" name="Approve request" />
<sequenceFlow id='flow3' sourceRef='approveTask' targetRef='approveOrDissaprove' />
<serviceTask id='approveOrDissaprove' name='Store decision'
activiti:expression="${loanRequest.setApproved(approvedByManager)}" />
<sequenceFlow id='flow4' sourceRef='approveOrDissaprove' targetRef='exclusiveGw' />
<exclusiveGateway id="exclusiveGw" name="Exclusive Gateway approval" />
<sequenceFlow id="endFlow1" sourceRef="exclusiveGw" targetRef="theEnd">
<conditionExpression xsi:type="tFormalExpression">${loanRequest.approved}</conditionExpression>
</sequenceFlow>
<sequenceFlow id="endFlow2" sourceRef="exclusiveGw" targetRef="sendRejectionLetter">
<conditionExpression xsi:type="tFormalExpression">${!loanRequest.approved}</conditionExpression>
</sequenceFlow>
<userTask id="sendRejectionLetter" name="Send rejection letter" />
<sequenceFlow id='flow5' sourceRef='sendRejectionLetter' targetRef='theOtherEnd' />
<endEvent id='theEnd' />
<endEvent id='theOtherEnd' />
</process>
</definitions>感谢各位的阅读，以上就是“如何配置工作流引擎Activiti集成JPA持久化保存流程数据”的内容了，经过本文的学习后，相信大家对如何配置工作流引擎Activiti集成JPA持久化保存流程数据这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是天达云，小编将为大家推送更多相关知识点的文章，欢迎关注！