1、创建Springboot项目
打开IDEA,通过File -> New -> Project… -> Spring Initializr 创建一个新的Springboot项目
pom.xml文件内容:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns
xsi:schemaLocation
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>org.tntxia</groupId>
<artifactId>flowable</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>flowable-spring-boot</name>
<description>flowable-spring-boot</description>
<properties>
<java.version>17</java.version>
<flowable.version>6.7.2</flowable.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2、加入Flowable依赖包
修改pom.xml文件
"properties"属性下加入:
<flowable.version>6.7.2</flowable.version>
注意,请确保Flowable版本与Springboot版本匹配,否则会无法启动。查看Flowable不同版本对应的springboot版本,参考:https:///JinYJ2014/article/details/121530632
"dependencies"属性下加入:
<dependency>
<groupId>org.flowable</groupId>
<artifactId>flowable-spring-boot-starter</artifactId>
<version>${flowable.version}</version>
</dependency>
这个依赖会自动向classpath添加正确的Flowable与Spring依赖。
注意:有时候,依赖JAR无法自动获取,可以右键点击项目,并选择 Maven ->Reload Project以强制手动刷新。
现在可以编写Spring Boot应用了:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class FlowableExampleApplication {
public static void main(String[] args) {
SpringApplication.run(FlowableExampleApplication.class, args);
}
}
Flowable需要数据库来存储数据。运行上面的代码会得到异常提示,指出需要在classpath中添加数据库驱动依赖。
3、添加数据源
现在添加MySQL数据库依赖:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
</dependency>
注意:MySQL依赖包版本根据自己所连接的数据库版本修改,否则可能会连接失败
application.properties文件中添加数据源
spring.datasource.url=spring.datasource.url=jdbc:mysql://127.0.0.1:3306/flowable?useSSL=false&characterEncoding=UTF-8&serverTimezone=UTC&nullCatalogMeansCurrent=true
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.username=jinyangjie
spring.datasource.password=jinyangjie
应用成功启动后,查看数据库,可以看到,已经自动创建了Flowable表:
注意:如果出现“Caused by: java.lang.RuntimeException: Exception while initializing Database connection”的错误,请确保数据源的配置项正确,并检查MySQL依赖包版本是否匹配
4、REST支持
4.1 添加REST依赖
通常我们的应用会使用REST API。添加下列依赖:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>${spring.boot.version}</version>
</dependency>
下面做个Controller和Service层的简单使用示例,例子来源于Flowable官方文档。
4.2 添加流程文件
resources/processes目录下的任何BPMN 2.0流程定义都会被自动部署。创建processes目录,并在其中创建示例流程定义(命名为one-task-process.bpmn20.xml)。
<?xml version="1.0" encoding="UTF-8"?>
<definitions
xmlns
targetNamespace="Examples">
<process id="oneTaskProcess" name="The One Task Process">
<startEvent id="theStart" />
<sequenceFlow id="flow1" sourceRef="theStart" targetRef="theTask" />
<userTask id="theTask" name="my task" flowable:assignee="jinyangjie" />
<sequenceFlow id="flow2" sourceRef="theTask" targetRef="theEnd" />
<endEvent id="theEnd" />
</process>
</definitions>
4.3 serivice层代码示例
创建一个新的Spring服务类,并创建两个方法:一个用于启动流程,另一个用于获得给定任务办理人的任务列表。在这里只是简单地包装了Flowable调用,在实际使用场景中会比这复杂得多。
import org.flowable.engine.RuntimeService;
import org.flowable.engine.TaskService;
import org.flowable.task.api.Task;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;
@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();
}
}
4.4 controller层代码示例
@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;
= name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
= name;
}
}
}
Spring Boot会自动扫描组件,并找到我们添加在应用类上的@Service与@RestController。再次运行应用,现在可以与REST API交互了。例如使用cURL:
[{"id":"b6350a6d-7070-11ec-bd1b-0a0027000006","name":"my task"}]
5、小结
本篇介绍了Springboot的初步集成,很明显还有很多Spring Boot相关的内容还没有提及,比如打包WAR文件、Spring Security支持等,这些将在后面的章节中介绍。