activiti6.0整合springboot2.x以及bug解
springboot在整合activiti时，会有一些官方bug。那么接下来将讲述如何springboot2.x完美整合activiti。
如果想直接看如何解决以及整合步骤不需要知道原理，请直接看末尾总结
一、引入pom文件
<dependency>
<groupId>org.activiti</groupId>
<artifactId>activiti-spring-boot-starter-basic</artifactId>
<version>6.0.0</version>
</dependency>
二、配置数据源
spring:
datasource:
url: jdbc:mysql://localhost:3306/db_activiti
username: root
password: 1234
driver-class-name: com.mysql.jdbc.Driver
至此一般来讲，应该是可以启动项目的。接下来启动试一试
发现启动出错，这里放一些出错代码
Failed to introspect annotations on class org.activiti.spring.boot.SecurityAutoConfiguration$$EnhancerBySpringCGLIB$$d26f5901
Failed to introspect annotations on class org.activiti.spring.boot.SecurityAutoConfiguration$$EnhancerBySpringCGLIB$$d26f5901
从上述代码可知是在初始化SecurityAutoConfiguration的时候出现错误，那么我们一般也不需要Security这个框架，直接将此配置类给排除掉，就可以了。
@SpringBootApplication(exclude = {org.activiti.spring.boot.SecurityAutoConfiguration.class})
我们再来启动，发现还是有问题，那么这次问题是什么呢？
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.activiti.spring.SpringProcessEngineConfiguration]
Caused by: java.io.FileNotFoundException: class path resource [processes/] cannot be resolved to URL because it does not exist
看起来好像是由于根目录下的processes文件夹没有找到而报错，顾名思义，一看这应该是activiti默认将根目录下的processes文件夹作为统一放置流程资源文件的地方。
那么如何解决呢？这里有两种解决办法
- 第一种
第一种当然很简单了，既然processes文件夹找不到，直接创建一个就好了呗
- 第二种
通过源码来分析，既然是org.activiti.spring.SpringProcessEngineConfiguration构建失败，那么继续看出错：
at org.activiti.spring.boot.DataSourceProcessEngineAutoConfiguration$DataSourceProcessEngineConfiguration.springProcessEngineConfiguration(DataSourceProcessEngineAutoConfiguration.java:57) ~[activiti-spring-boot-starter-basic-6.0.0.jar:na]
可知org.activiti.spring.SpringProcessEngineConfiguration是由org.activiti.spring.boot.DataSourceProcessEngineAutoConfiguration来构建，那么我们在这个类中打个断点，查看构建逻辑。
- DataSourceProcessEngineAutoConfiguration.java
@Bean
@ConditionalOnMissingBean
public SpringProcessEngineConfiguration springProcessEngineConfiguration(DataSource dataSource, PlatformTransactionManager transactionManager, SpringAsyncExecutor springAsyncExecutor) throws IOException {
return this.baseSpringProcessEngineConfiguration(dataSource, transactionManager, springAsyncExecutor);
}
进入这个方式之后走到了AbstractProcessEngineAutoConfiguration的baseSpringProcessEngineConfiguration逻辑中
- AbstractProcessEngineAutoConfiguration.java
protected SpringProcessEngineConfiguration baseSpringProcessEngineConfiguration(DataSource dataSource, PlatformTransactionManager platformTransactionManager, SpringAsyncExecutor springAsyncExecutor) throws IOException {
List<Resource> procDefResources = this.discoverProcessDefinitionResources(this.resourceLoader, this.activitiProperties.getProcessDefinitionLocationPrefix(), this.activitiProperties.getProcessDefinitionLocationSuffixes(), this.activitiProperties.isCheckProcessDefinitions());
.......
...
..
}
查看discoverProcessDefinitionResources实现
public List<Resource> discoverProcessDefinitionResources(ResourcePatternResolver applicationContext, String prefix, List<String> suffixes, boolean checkPDs) throws IOException {
if (!checkPDs) {
return new ArrayList();
} else {
List<Resource> result = new ArrayList();
Iterator var6 = suffixes.iterator();
while(true) {
Resource[] resources;
do {
do {
if (!var6.hasNext()) {
if (result.isEmpty()) {
logger.info(String.format("No process definitions were found for autodeployment"));
}
return result;
}
String suffix = (String)var6.next();
String path = prefix + suffix;
resources = applicationContext.getResources(path);
} while(resources == null);
} while(resources.length <= 0);
Resource[] var10 = resources;
int var11 = resources.length;
for(int var12 = 0; var12 < var11; ++var12) {
Resource resource = var10[var12];
result.add(resource);
}
}
}
}
首先对调用上述discoverProcessDefinitionResources方式时的参数的值进行说明
this.processDefinitionLocationPrefix = "classpath:/processes/";
this.processDefinitionLocationSuffixes = Arrays.asList("**.bpmn20.xml", "**.bpmn");
private boolean checkProcessDefinitions = true;
所以也就是当checkProcessDefinitions为true时，将获取所有根目录下processes文件下后缀.bpmn20.xml和.bpmn的所有资源，否则直接返回一个空的resource集合。到这里想必已经知道怎么改了，直接设置checkProcessDefinitions为false，让它在初始化启动时不从processes文件夹下加载资源就可以了。
只需要在application.yml添加
spring:
activiti:
check-process-definitions: false
此时查看数据库中，activiti的表已经创建好啦！
三、总结
springboot2.x整合activiti6.0步骤
- 第一步：加入pom依赖
<dependency>
<groupId>org.activiti</groupId>
<artifactId>activiti-spring-boot-starter-basic</artifactId>
<version>6.0.0</version>
</dependency>
-
第二步：排除org.activiti.spring.boot.SecurityAutoConfiguration的构建
启动类注解上添加配置
@SpringBootApplication(exclude = {org.activiti.spring.boot.SecurityAutoConfiguration.class})
- 第三步：在classpath下添加processes文件夹或者在application.yml中添加配置
spring:
activiti:
check-process-definitions: false
