BPMN2.0（Business Process Model and Notation）是一套业务流程模型与符号建模标准，以XML为载体，以符号可视化业务，支持精准的执行语义来描述元素的操作。
Flowable诞生于Activiti，是一个使用Java编写的轻量级业务流程引擎。Flowable流程引擎可用于部署BPMN 2.0流程定义，可以十分灵活地加入你的应用/服务/构架。
导入Maven依赖
<dependency>
<groupId>org.flowable</groupId>
<artifactId>flowable-spring-boot-starter-basic</artifactId>
<version>6.4.1</version>
</dependency>
<dependency>
<groupId>org.flowable</groupId>
<artifactId>flowable-json-converter</artifactId>
<version>6.4.1</version>
</dependency>
从流程模型导出流程定义bpmn20.xml
通过流程编辑器制作的流程模型（如下图所示），可以通过模型ID（Model.id），调用flowable 的 RepositoryService 来生成bpmn20.xml。
@Service
public class MyModelServiceImpl implements MyModelService {
@Autowired
private RepositoryService repositoryService;
/**
* 通过模型ID，生成模型BPMN20.xml
* @param guid 模型id,即model.id
* @return
* @throws Exception
*/
@Override
public ResultDTO genXml(String guid throws Exception {
/**通过ID获取模型 **/
Model modelData = repositoryService.getModel(guid;
byte[] bytes = repositoryService.getModelEditorSource(modelData.getId(;
if (bytes == null {
return ResultDTO.failureCustom("模型数据为空，请先设计流程并成功保存，再进行发布。";
}
JsonNode modelNode = new ObjectMapper(.readTree(bytes;
BpmnModel model = new BpmnJsonConverter(.convertToBpmnModel(modelNode;
if (model.getProcesses(.size( == 0 {
return ResultDTO.failureCustom("数据模型不符要求，请至少设计一条主线流程。";
}
/** 设置名称 **/
model.getMainProcess(.setName(modelData.getName(;
/** 设置 targetNamespace **/
if(StringUtils.isNotBlank(modelData.getCategory( {
model.setTargetNamespace(modelData.getCategory(;
}
byte[] bpmnBytes = new BpmnXMLConverter(.convertToXML(model;
String xml = new String(bpmnBytes, "UTF-8";
return ResultDTO.success(xml;
}
}
运行效果如下：
{% asset_img res1.gif 导出效果 %}
从流程定义导出流程定义bpmn20.xml
@RestController
@Slf4j
public class ProcessController {
@Autowired
private MyProcessService processService;
/**
* 通过processDefinition.id和resType导出流程XML或图片资源
* @param id processDefinition.id
* @param resType 取值 “image/png”或“text/xml”
* @param response
* @throws Exception
*/
@GetMapping(value = "/res/exp"
@ApiOperation("通过processDefinition.id和resType导出流程XML或图片资源"
public void resourceRead(@RequestParam("id" String id,@RequestParam("resType" String resType, HttpServletResponse response throws Exception {
/** resType取值 “image/png”或“text/xml” **/
InputStream resourceAsStream = processService.resourceRead(id,resType;
byte[] b = new byte[1024];
int len = -1;
while ((len = resourceAsStream.read(b, 0, 1024 != -1 {
response.getOutputStream(.write(b, 0, len;
}
}
}
@Service
public class MyProcessServiceImpl implements MyProcessService {
@Autowired
private RepositoryService repositoryService;
@Override
public InputStream resourceRead(String id, String resType throws Exception {
ProcessDefinition processDefinition = repositoryService.createProcessDefinitionQuery(.processDefinitionId(id.singleResult(;
String resourceName = "";
if (resType.equals("image/png" {
resourceName = processDefinition.getDiagramResourceName(;
} else if (resType.equals("text/xml" {
resourceName = processDefinition.getResourceName(;
}
InputStream resourceAsStream = repositoryService.getResourceAsStream(processDefinition.getDeploymentId(, resourceName;
return resourceAsStream;
}
}
运行效果如下：
项目源码仓库