Activiti-01

1, Activiti官网：http://www.activiti.org/  主页可以看到jar包的下载.

2, 进入http://www.activiti.org/userguide/index.html 用户指导页进行学习研究.

3, 在maven中引入activiti jar 文件的

To include the activiti engine in your project, add following dependency (note that you need to change the version to the latest release):

<dependency>
  <groupId>org.activiti</groupId>
  <artifactId>activiti-engine</artifactId>
  <version>5.x</version>
</dependency>
      

And if you use Activiti with the Spring integration, then your dependencies could look like this:

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>spring.version</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-jdbc</artifactId>
  <version>spring.version</version>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-tx</artifactId>
  <version>spring.version</version>
</dependency>

4, 如果不使用maven，可以在下载的zip包的libs文件夹中看到所有的jar文件（包括源文件jar）必须的依赖包

org.activiti:activiti-engine:jar:5.12.1+- org.apache.commons:commons-email:jar:1.2:compile|  +- javax.mail:mail:jar:1.4.1:compile|  \- javax.activation:activation:jar:1.1:compile+- commons-lang:commons-lang:jar:2.4:compile+- org.mybatis:mybatis:jar:3.1.1:compile+- org.springframework:spring-beans:jar:3.1.2.RELEASE:compile|  \- org.springframework:spring-core:jar:3.1.2.RELEASE:compile|     +- org.springframework:spring-asm:jar:3.1.2.RELEASE:compile|     \- commons-logging:commons-logging:jar:1.1.1:compile\- joda-time:joda-time:jar:2.1:compile  
 
Note: the mail jars are only needed if you are using the mail service task
 
得到ProcessEngine对象是很容易的，会去classpath中找 activiti.cfg.xml文件.

ProcessEngine processEngine =ProcessEngines.getDefaultProcessEngine();

<beans xmlns="http://www.springframework.org/schema/beans"        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">
 
  <bean id="processEngineConfiguration"       class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">      <propertyname="jdbcUrl"value="jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000"/>    <propertyname="jdbcDriver"value="org.h2.Driver"/>    <propertyname="jdbcUsername"value="sa"/>    <propertyname="jdbcPassword"value=""/>        <propertyname="databaseSchemaUpdate"value="true"/>        <propertyname="jobExecutorActivate"value="false"/>        <propertyname="mailServerHost"value="mail.my-corp.com"/>     <propertyname="mailServerPort"value="5025"/>      </bean>
 
</beans>

5  这是一个基于Spring的xml文件，但是并不意味着它只能在spring中配置

ProcessEngineConfiguration 对象可以使用配置文件创建也可以指定自己的bean名称，如

ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault();ProcessEngineConfiguration.createProcessEngineConfigurationFromResource(String resource);ProcessEngineConfiguration.createProcessEngineConfigurationFromResource(String resource,String beanName);ProcessEngineConfiguration.createProcessEngineConfigurationFromInputStream(InputStream inputStream);ProcessEngineConfiguration.createProcessEngineConfigurationFromInputStream(InputStream inputStream,String beanName);

所有ProcessEngineConfiguration.createXXX() 方法返回ProcessEngineConfiguration对象，再调用buildProcessEngine()方法即可返回ProcessEngine 对象。

　activiti.cfg.xml 必须有一个bean的id为  'processEngineConfiguration'.，这个bean是用来构造ProcessEngine的

<bean id="processEngineConfiguration"

class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration"> ，class可以指定的类

• org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration: the process engine is used in a standalone way. Activiti will take care of the transactions. By default, the database will only be checked when the engine boots (and an exception is thrown if there is no Activiti schema or the schema version is incorrect).

• org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration: this is a convenience class for unit testing purposes. Activiti will take care of the transactions. An H2 in-memory database is used by default. The database will be created and dropped when the engine boots and shuts down. When using this, probably no additional configuration is needed (except when using for example the job executor or mail capabilities).

• org.activiti.spring.SpringProcessEngineConfiguration:To be used when the process engine is used in a Spring environment. See the Spring integration section for more information.

• org.activiti.engine.impl.cfg.JtaProcessEngineConfiguration: To be used when the engine runs in standalone mode, with JTA transactions.

有两种方式配置Activiti引擎用到的数据库，第一种是jdbc方式

<propertyname="jdbcUrl"value="jdbc:h2:mem:activiti;DB_CLOSE_DELAY=1000"/><propertyname="jdbcDriver"value="org.h2.Driver"/><propertyname="jdbcUsername"value="sa"/><propertyname="jdbcPassword"value=""/>

The data source that is constructed based on the provided JDBC properties will have the default MyBatis connection pool settings. The following attributes can optionally be set to tweak that connection pool (taken from the MyBatis documentation):

基于JDBC属性构造数据源的方式默认使用Mybatis连接池设置，下面属性可以设置调整连接池

• jdbcMaxActiveConnections: 最大活动连接数. Default is 10.

•  jdbcMaxIdleConnections:  空闲连接数

• jdbcMaxCheckoutTime: 一个连接在返回之前被检查的时间 . Default is 20000 (20 seconds).

• jdbcMaxWaitTime: 这是一个低级设置，一般都是默认不修改 Default is 20000 (20 seconds).

<bean id="dataSource"class="org.apache.commons.dbcp.BasicDataSource">  <property name="driverClassName"value="com.mysql.jdbc.Driver"/>  <property name="url"value="jdbc:mysql://localhost:3306/activiti"/>  <property name="username"value="activiti"/>  <property name="password"value="activiti"/>  <property name="defaultAutoCommit"value="false"/></bean>      
 
<bean id="processEngineConfiguration"class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">      <propertyname="dataSource"ref="dataSource"/>

...>
必须确保数据源的依赖库在classpath中下面属性也应该被设置，无论是jdbc还是data source databaseType： 数据库类型  ，可能的取值 {h2, mysql, oracle, postgres, mssql, db2}

    databaseSchemaUpdate:  流程引擎启动关闭时数据库的策略.

false 默认：检查数据库schema版本，在流程引擎创建或抛异常时

           true 在部署流程引擎时，检查数据库schema，不存在就创建           create-drop 在流程引擎创建时创建数据库schema，关闭时删除数据库schema

在 activiti-5.13/database下可以看到可以看到具体的sql dll文件
 

• engine: 引擎执行必须的表. Required.

• identity:  这些表包含用户，组，用户在组中的身份，是可选的 这些表应该被使用当使用默认的身份管理引擎的装载.

• history: 包含历史和审计信息. 可选的，当历史级别设置为none时是不需要的

Activiti数据库都以ACT_开头 .

ACT_RE_*:  'RE' stands for repository. Tables with this prefix contain 'static' information such as process definitions and process resources (images, rules, etc.).

• ACT_RU_*: 'RU' stands for runtime. These are the runtime tables, that contain the runtime data of process instances, user tasks, variables, jobs, etc. Activiti only stores the runtime data during process instance execution, and removes the records when a process instance ends. This keeps the runtime tables small and fast.

• ACT_ID_*: 'ID'  stands for identity. These tables contain identity information, such as users, groups, etc.

• ACT_HI_*: 'HI' stands for history. These are the tables that contain historic data, such as past process instances, variables, tasks, etc.

• ACT_GE_*: general data, which is used in various use cases.

升级数据库需要配置databaseSchemaUpdate为true
 
<beans ... >
 
  <beanid="processEngineConfiguration"class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">    <!-- ... -->    <propertyname="databaseSchemaUpdate"value="true"/>        <!-- ... -->  </bean>
 
</beans>

任务执行器的激活

JobExecutor管理一对线程或者异步消息的组件，以为测试的复杂，被用于多线程。.因此它的api允许(ManagementService.createJobQuery) and执行(ManagementService.executeJob)  ，为了避免执行者的冲突，经常被关闭。默认情况， JobExecutor 被激活当引擎启动时.

<property name="jobExecutorActivate"value="false"/>

当你不想在引擎启动的时候激活JobExecutor ，可以设置上面的值为false

邮件服务配置

为了发送邮件，合法的SMTP 服务器是必须的，将下面属性设置到activiti.cfg.xml

Property	Required?	Description
mailServerHost	no	邮件服务器(e.g. mail.mycorp.com). 默认localhost
mailServerPort	yes, if not on the default port	The port for SMTP traffic on the mail server. The default is 25
mailServerDefaultFrom	no	The default e-mail address of the sender of e-mails, when none is provided by the user. By default this is activiti@activiti.org
mailServerUsername	如果适用您的服务器	Some mail servers require credentials for sending e-mail. By default not set.
mailServerPassword	如果适用您的服务器	Some mail servers require credentials for sending e-mail. By default not set.
mailServerUseSSL	如果适用您的服务器	Some mail servers require ssl communication. By default set to false.

定义邮件任务

<serviceTask id="sendMail"activiti:type="mail">   

邮件任务通过属性注入方式配置，. 所有的属性值都可以包含 EL 表达式,

Table 8.2. Mail server configuration

Property	Required?	Description
to	yes	The recipients if the e-mail. Multiple recipients are defined in a comma-separated list
from	no	The sender e-mail address. If not provided, the default configured from address is used.
subject	no	The subject of the e-mail.
cc	no	The cc's of the e-mail. Multiple recipients are defined in a comma-separated list
bcc	no	The bcc's of the e-mail. Multiple recipients are defined in a comma-separated list
charset	no	Allows to change the charset of the email, which is necessary for many non-English languages.
html	no	A piece of HTML that is the content of the e-mail.
text	no	The content of the e-mail, in case one needs to send plain none-rich e-mails. Can be used in combination with html, for e-mail clients that don't support rich content. The client will then fall back to this text-only alternative.

邮件任务的例子

<serviceTaskid="sendMail"activiti:type="mail">  <extensionElements>    <activiti:fieldname="from"stringValue="order-shipping@thecompany.com"/>    <activiti:fieldname="to"expression="${recipient}"/>    <activiti:fieldname="subject"expression="Your order ${orderId} has been shipped"/>    <activiti:fieldname="html">      <activiti:expression>        <![CDATA[          <html>            <body>              Hello ${male ? 'Mr.' : 'Mrs.' } ${recipientName},<br/><br/>                               As of ${now}, your order has been <b>processed and shipped</b>.<br/><br/>                                Kind regards,<br/>                                TheCompany.            </body>          </html>        ]]>      </activiti:expression>    </activiti:field>        </extensionElements></serviceTask>                               

历史的配置

<propertyname="history"value="audit"/>

所有的流程定义都会被缓存，下面是设置缓存大小

<propertyname="processDefinitionCacheLimit"value="10"/>使用的是LRU 算法进行缓存策略

日志

在Activiti 5.12, SLF4J日志框架被使用。所有日志(activiti, spring, mybatis, ...)被使用SLF4J ，允许你选择日志框架的实现
默认这个jar包没有在 activiti-engine中引入，需要自己引入。

<dependency>  <groupId>org.slf4j</groupId>  <artifactId>slf4j-log4j12</artifactId>　<version>XXX</version></dependency>

t特别重要，当使用容器commons-logging在classpath时: 为了能够路由spring-logging通过SLF4J,  一个桥要被使用

<dependency>

<groupId>org.slf4j</groupId>

<artifactId>jcl-over-slf4j</artifactId>

</dependency>