camunda_04_quickstart

目标

• 设计和部署第一个简单流程
• 使用Java实现流程处理
• 完成流程启动测试

设计第一个流程

建模注意事项

• 模型文件和部署名其实并不重要,最重要是流程的​​Id​​, ProcessEngine是按照这个Id管理流程.
• 流程要设定为​​Executable​​.

步骤

2. 使用Model新建一个 camunda 7的模型文件, 命名为payment.bpm , 流程Id 设定为​​payment-retrieval（231, 243, 237); padding: 0px 3px; border-radius: 4px; overflow-wrap: break-word; text-indent: 0px;">​External​​,Topic设定为​​charge-card​​
3. 
   



4. BPMN xml 代码

<?xml version="1.0" encoding="UTF-8"?>
<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:camunda="http://camunda.org/schema/1.0/bpmn" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:modeler="http://camunda.org/schema/modeler/1.0" id="Definitions_1xvrd7w" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="5.2.0" modeler:executionPlatform="Camunda Platform" modeler:executionPlatformVersion="7.17.0">
  <bpmn:process id="payment-retrieval（232, 232, 232); background: rgb(249, 249, 249);">
<mirrors>
         <mirror>
            <id>aliyun</id>
            <name>mirror from maven aliyun</name>
            <url>https://maven.aliyun.com/repository/central</url>
            <mirrorOf>central</mirrorOf>
        </mirror>
  </mirrors>
pom.xml
</dependency>
        <dependency>
            <groupId>org.camunda.bpm</groupId>
            <artifactId>camunda-external-task-client</artifactId>
            <version>7.17.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.6.1</version>
        </dependency>
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.1</version>
        </dependency>
</dependencies>
java 业务代码
camunda 的 ExternalTaskClient 是一个Listener类, 我们程序使用 ExternalTaskClient 就可以成为一个后台daemon程序, 后面再专门写个博客分析一下 camunda-external-task-client jar.

在我们的程序中, 使用ExternalTaskClient可以非常方便监听流程中的External Task Service设定的 topic, 完成业务处理, 并标记该Task为结束.
package javatest;

import java.text.MessageFormat;
import java.util.logging.Logger;

import org.camunda.bpm.client.ExternalTaskClient;

public class ChargeCardWorker {
  private final static Logger logger = Logger.getLogger(ChargeCardWorker.class.getName());

  public static void main(String[] args) {
    logger.info("ExternalTaskClient setup");
    ExternalTaskClient client = ExternalTaskClient.create().baseUrl("http://localhost:8080/engine-rest")
        .asyncResponseTimeout(10000).build();

    // 订阅并处理第1个ExternalTask的topic
    client.subscribe("charge-card").lockDuration(1000).handler((externalTask, externalTaskService) -> {
      // 获取流程信息
      String item = (String) externalTask.getVariable("item");
      Long amount = (Long) externalTask.getVariable("amount");

      // 业务逻辑
      logger.info(
          MessageFormat.format("Charging credit card with an amount of {0} for the item {1}", amount, item));

      // 完成 Task
      externalTaskService.complete(externalTask);
    }).open();

    // 订阅并处理第2个ExternalTask的topic
    // 省略

    logger.info("Listening topics...");
  }
}
启动流程
确保java程序提前运行, 然后使用VS code+Rest Client 发起一个启动流程命令:
POST http://localhost:8080/engine-rest/process-definition/key/payment-retrieval/start HTTP/1.1
Content-Type: application/json

{
    "variables": {
        "amount": {
            "value":555,
            "type":"long"
        },
        "item": {
            "value": "item-xyz"
        }
    }
}
Rest API的返回信息:

Java程序端的输出: