Liferay7 BPM门户开发之5: Activiti和Spring集成

参考文档：

https://github.com/jbarrez/spring-boot-with-activiti-example
https://github.com/sxyx2008/spring-activiti-webapp
http://www.cnblogs.com/hongwz/p/5548473.html

Spring典型配置

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"><bean id="dataSource" class="org.springframework.jdbc.datasource.SimpleDriverDataSource">
<property name="driverClass" value="org.h2.Driver" />
<property name="url" value="jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000" />
<property name="username" value="sa" />
<property name="password" value="" />
</bean><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</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="jobExecutorActivate" value="false" />
</bean><bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
<property name="processEngineConfiguration" ref="processEngineConfiguration" />
</bean><bean id="repositoryService" factory-bean="processEngine" factory-method="getRepositoryService" />
<bean id="runtimeService" factory-bean="processEngine" factory-method="getRuntimeService" />
<bean id="taskService" factory-bean="processEngine" factory-method="getTaskService" />
<bean id="historyService" factory-bean="processEngine" factory-method="getHistoryService" />
<bean id="managementService" factory-bean="processEngine" factory-method="getManagementService" />...

自定义的实体类可以这么设置：

<beans>
...
<tx:annotation-driven transaction-manager="transactionManager"/><bean id="userBean" class="org.activiti.spring.test.UserBean">
<property name="runtimeService" ref="runtimeService" />
</bean><bean id="printer" class="org.activiti.spring.test.Printer" /></beans>

写注解：

@ContextConfiguration("classpath:org/activiti/spring/test/transaction/SpringTransactionIntegrationTest-context.xml")

然后就可以访问Activiti的工厂类和自定义的实体类，
比如RepositoryService的实例这样获得，同时这也是Spring集成环境下的bpmn文件的部署方式：

RepositoryService repositoryService =
(RepositoryService) applicationContext.getBean("repositoryService");
String deploymentId = repositoryService
.createDeployment()
.addClasspathResource("org/activiti/spring/test/hello.bpmn20.xml")
.deploy()
.getId();

new 一个自定义的实体类实例：

UserBean userBean = (UserBean) applicationContext.getBean("userBean");
userBean.hello();

自定义的实体类：

public class UserBean {/** Spring 注入 */
private RuntimeService runtimeService;@Transactional
public void hello() {
runtimeService.startProcessInstanceByKey("helloProcess");
}public void setRuntimeService(RuntimeService runtimeService) {
this.runtimeService = runtimeService;
}
}

表达式

在流程定义文件bpmn20.xml使用表达式

表达式可以灵活动态的使用类的方法，他可以实现流程计算逻辑和实体类的解耦，说具体些就是流程定义文件可以不用Hardcode了，直接通过接口调用的形式访问具体的类，
举例，定义一个输出打印的类，

public class Printer {public void printMessage() {System.out.println("hello world");
}
}

在Spring里注册：

<beans>
...<bean id="printer" class="org.activiti.examples.spring.Printer" /></beans>

建立关联配置：

<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
...
<property name="beans">
<map>
<entry key="printer" value-ref="printer" />
</map>
</property>
</bean>

最后，就可以在流程定义文件bpmn20.xml使用表达式，定义了一个serviceTask：
这种调用方法非常灵活，也是集成Spring高效和方便的地方

<definitions id="definitions"><process id="helloProcess"><startEvent id="start" />
<sequenceFlow id="flow1" sourceRef="start" targetRef="print" /><serviceTask id="print" activiti:expression="#{printer.printMessage()}" />
<sequenceFlow id="flow2" sourceRef="print" targetRef="end" /><endEvent id="end" /></process></definitions>

使用Spring自动部署bpmn20.xml
仅当文件变化的时候，才会被重新部署，特别方便用于系统调试，程序员必备

<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
...
<property name="deploymentResources"
value="classpath*:/org/activiti/spring/test/autodeployment/autodeploy.*.bpmn20.xml" />
</bean><bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
<property name="processEngineConfiguration" ref="processEngineConfiguration" />
</bean>

可以使用通配符

<property name="deploymentResources" value="classpath*:/activiti/*.bpmn" />
<property name="deploymentMode" value="single-resource" />

Hibernate 4.2.x集成

POM：

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${org.springframework.version}</version>
</dependency><dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<version>1.4.183</version>
</dependency>

配置是不是很简单？

然后就可以开发了

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;@Configuration
@ComponentScan
@EnableAutoConfiguration
public class MyApplication {public static void main(String[] args) {
SpringApplication.run(MyApplication.class, args);
}@Bean
public CommandLineRunner init(final RepositoryService repositoryService,
final RuntimeService runtimeService,
final TaskService taskService) {return new CommandLineRunner() {
@Override
public void run(String... strings) throws Exception {
System.out.println("Number of process definitions : "
+ repositoryService.createProcessDefinitionQuery().count());
System.out.println("Number of tasks : " + taskService.createTaskQuery().count());
runtimeService.startProcessInstanceByKey("oneTaskProcess");
System.out.println("Number of tasks after process start: " + taskService.createTaskQuery().count());
}
};}
}

使用MySQL数据库
POM：

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.34</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
<version>8.0.15</version>
</dependency>

数据源

@Bean
public DataSource database() {
return DataSourceBuilder.create()
.url("jdbc:mysql://127.0.0.1:3306/activiti-spring-boot?characterEncoding=UTF-8")
.username("alfresco")
.password("alfresco")
.driverClassName("com.mysql.jdbc.Driver")
.build();
}

REST开发扩展

Spring Boot可以快速开发web api接口，REST对集成第三方应用非常重要
POM：

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>${spring.boot.version}</version>
</dependency>

开发服务类，服务类是用于控制器的重复调用，即帮助类

@Service
public class MyService {@Autowired
private RuntimeService runtimeService;@Autowired
private TaskService taskService;@Transactional
public void startProcess() {
runtimeService.startProcessInstanceByKey("oneTaskProcess");
}@Transactional
public List<Task> getTasks(String assignee) {
return taskService.createTaskQuery().taskAssignee(assignee).list();
}}

控制器：
注意：启动流程使用POST，获取任务使用了GET，在输出时自动把实体类（TaskRepresentation）转换为JSON格式

@RestController
public class MyRestController {@Autowired
private MyService myService;@RequestMapping(value="/process", method= RequestMethod.POST)
public void startProcessInstance() {
myService.startProcess();
}@RequestMapping(value="/tasks", method= RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
public List<TaskRepresentation> getTasks(@RequestParam String assignee) {
List<Task> tasks = myService.getTasks(assignee);
List<TaskRepresentation> dtos = new ArrayList<TaskRepresentation>();
for (Task task : tasks) {
dtos.add(new TaskRepresentation(task.getId(), task.getName()));
}
return dtos;
}static class TaskRepresentation {private String id;
private String name;public TaskRepresentation(String id, String name) {
this.id = id;
this.name = name;
}public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}}}

需要注意@ComponentScan一定在加在application类的注解

测试：
curl -X POST http://localhost:8080/process
curl http://localhost:8080/tasks?assignee=kermit
[{"id":"10004","name":"my task"}]

JPA支持

默认JPA是Hibernate

POM：

<dependency>
<groupId>org.activiti</groupId>
<artifactId>activiti-spring-boot-starter-jpa</artifactId>
<version>${activiti.version}</version>
</dependency>

实体类：

@Entity
class Person {@Id
@GeneratedValue
private Long id;private String username;private String firstName;private String lastName;private Date birthDate;public Person() {
}public Person(String username, String firstName, String lastName, Date birthDate) {
this.username = username;
this.firstName = firstName;
this.lastName = lastName;
this.birthDate = birthDate;
}public Long getId() {
return id;
}public void setId(Long id) {
this.id = id;
}public String getUsername() {
return username;
}public void setUsername(String username) {
this.username = username;
}public String getFirstName() {
return firstName;
}public void setFirstName(String firstName) {
this.firstName = firstName;
}public String getLastName() {
return lastName;
}public void setLastName(String lastName) {
this.lastName = lastName;
}public Date getBirthDate() {
return birthDate;
}public void setBirthDate(Date birthDate) {
this.birthDate = birthDate;
}
}

如果不使用in-memory数据库，数据表不会自动建立，需要 application.properties 增加配置：
spring.jpa.hibernate.ddl-auto=update

增加接口：

public interface PersonRepository extends JpaRepository<Person, Long> {Person findByUsername(String username);}

服务类：

@Service
@Transactional
public class MyService {@Autowired
private RuntimeService runtimeService;@Autowired
private TaskService taskService;@Autowired
private PersonRepository personRepository;public void startProcess(String assignee) {Person person = personRepository.findByUsername(assignee);Map<String, Object> variables = new HashMap<String, Object>();
variables.put("person", person);
runtimeService.startProcessInstanceByKey("oneTaskProcess", variables);
}public List<Task> getTasks(String assignee) {
return taskService.createTaskQuery().taskAssignee(assignee).list();
}public void createDemoUsers() {
if (personRepository.findAll().size() == 0) {
personRepository.save(new Person("jbarrez", "Joram", "Barrez", new Date()));
personRepository.save(new Person("trademakers", "Tijs", "Rademakers", new Date()));
}
}}

在CommandLineRunner 初始化的时候，添加用户持久化数据（createDemoUsers()）

@Bean
public CommandLineRunner init(final MyService myService) {return new CommandLineRunner() {
public void run(String... strings) throws Exception {myService.createDemoUsers();
}
};}

控制器：

@RestController
public class MyRestController {@Autowired
private MyService myService;@RequestMapping(value="/process", method= RequestMethod.POST)
public void startProcessInstance(@RequestBody StartProcessRepresentation startProcessRepresentation) {
myService.startProcess(startProcessRepresentation.getAssignee());
}...static class StartProcessRepresentation {private String assignee;public String getAssignee() {
return assignee;
}public void setAssignee(String assignee) {
this.assignee = assignee;
}
}

流程定义再一次使用了表达式：

<userTask id="theTask" name="my task" activiti:assignee="${person.id}"/>

测试：POST一个流程启动者的username
curl -H "Content-Type: application/json" -d '{"assignee" : "jbarrez"}' http://localhost:8080/process
curl http://localhost:8080/tasks?assignee=1

[{"id":"12505","name":"my task"}]

更高级的内容可以自行研究：

Actuator support
Spring Integration support
Rest API integration
Spring Security support