springboot在整合activiti時(shí)，會(huì)有一些官方bug。那么接下來將講述如何springboot2.x完美整合activiti。

如果想直接看如何解決以及整合步驟不需要知道原理，請直接看末尾總結(jié)

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、配置數(shù)據(jù)源

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/db_activiti
    username: root
    password: 1234
    driver-class-name: com.mysql.jdbc.Driver

至此一般來講，應(yīng)該是可以啟動(dòng)項(xiàng)目的。接下來啟動(dòng)試一試
發(fā)現(xiàn)啟動(dòng)出錯(cuò)，這里放一些出錯(cuò)代碼

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

從上述代碼可知是在初始化SecurityAutoConfiguration的時(shí)候出現(xiàn)錯(cuò)誤，那么我們一般也不需要Security這個(gè)框架，直接將此配置類給排除掉，就可以了。

@SpringBootApplication(exclude = {org.activiti.spring.boot.SecurityAutoConfiguration.class})

我們再來啟動(dòng)，發(fā)現(xiàn)還是有問題，那么這次問題是什么呢？

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

看起來好像是由于根目錄下的processes文件夾沒有找到而報(bào)錯(cuò)，顧名思義，一看這應(yīng)該是activiti默認(rèn)將根目錄下的processes文件夾作為統(tǒng)一放置流程資源文件的地方。
那么如何解決呢？這里有兩種解決辦法

- 第一種

第一種當(dāng)然很簡單了，既然processes文件夾找不到，直接創(chuàng)建一個(gè)就好了唄

- 第二種

通過源碼來分析，既然是org.activiti.spring.SpringProcessEngineConfiguration構(gòu)建失敗，那么繼續(xù)看出錯(cuò)：

    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來構(gòu)建，那么我們在這個(gè)類中打個(gè)斷點(diǎn)，查看構(gòu)建邏輯。

• DataSourceProcessEngineAutoConfiguration.java

        @Bean
        @ConditionalOnMissingBean
        public SpringProcessEngineConfiguration springProcessEngineConfiguration(DataSource dataSource, PlatformTransactionManager transactionManager, SpringAsyncExecutor springAsyncExecutor) throws IOException {
            return this.baseSpringProcessEngineConfiguration(dataSource, transactionManager, springAsyncExecutor);
        }

進(jìn)入這個(gè)方式之后走到了AbstractProcessEngineAutoConfiguration的baseSpringProcessEngineConfiguration邏輯中

• 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實(shí)現(xiàn)

    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);
                }
            }
        }
    }

首先對調(diào)用上述discoverProcessDefinitionResources方式時(shí)的參數(shù)的值進(jìn)行說明

        this.processDefinitionLocationPrefix = "classpath:/processes/";
        this.processDefinitionLocationSuffixes = Arrays.asList("**.bpmn20.xml", "**.bpmn");
        private boolean checkProcessDefinitions = true;

所以也就是當(dāng)checkProcessDefinitions為true時(shí)，將獲取所有根目錄下processes文件下后綴.bpmn20.xml和.bpmn的所有資源，否則直接返回一個(gè)空的resource集合。到這里想必已經(jīng)知道怎么改了，直接設(shè)置checkProcessDefinitions為false，讓它在初始化啟動(dòng)時(shí)不從processes文件夾下加載資源就可以了。

只需要在application.yml添加

spring:
  activiti:
    check-process-definitions: false

此時(shí)查看數(shù)據(jù)庫中，activiti的表已經(jīng)創(chuàng)建好啦！

三、總結(jié)

springboot2.x整合activiti6.0步驟

• 第一步：加入pom依賴

        <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的構(gòu)建
  啟動(dòng)類注解上添加配置

@SpringBootApplication(exclude = {org.activiti.spring.boot.SecurityAutoConfiguration.class})

• 第三步：在classpath下添加processes文件夾或者在application.yml中添加配置

spring:
  activiti:
    check-process-definitions: false