Activity workflow engine

Hello everyone , I meet you again , I'm your friend, Quan Jun .

workflow activity Engine introduction case

1、 What is workflow ？ In short, workflow is to put a piece of information according to roles 、 Division of labor 、 The conditions are different, and the upward transmission is fixed , Data is transmitted in a fixed direction , Pass it on level by level , This kind of scene is OA , CRM / ERP There are many applications in . Usually, this operation itself can also be realized through logic , But the complexity is very high . And it's not easy to maintain . Therefore, the third-party engine framework is usually used to realize , Out of the engine itself simplifies the operation . More importantly, it is easy to maintain .

2、activity Workflow engine activity It is a relatively simple and easy workflow , The main operations are divided into the following steps

• utilize activity The plug-in draws the required logic flow chart
• Deployment process
• Start process
• Iterative processing flow
• End of the process

3、activity Environment building 1、 Create a new one maven project

2、 Import maven rely on

  <dependencies> 
    <dependency> 
      <groupId>org.mortbay.jetty</groupId>  
      <artifactId>jetty-util</artifactId>  
      <version>${jetty.version}</version>  
      <scope>provided</scope> 
    </dependency>  
    <dependency> 
      <groupId>org.mortbay.jetty</groupId>  
      <artifactId>jetty-management</artifactId>  
      <version>${jetty.version}</version>  
      <scope>provided</scope> 
    </dependency>  
    <dependency> 
      <groupId>org.activiti</groupId>  
      <artifactId>activiti-engine</artifactId>  
      <version>5.21.0</version> 
    </dependency>  
    <dependency> 
      <groupId>org.activiti</groupId>  
      <artifactId>activiti-spring</artifactId>  
      <version>5.21.0</version> 
    </dependency>  
    <dependency> 
      <groupId>org.codehaus.groovy</groupId>  
      <artifactId>groovy-all</artifactId>  
      <version>2.4.3</version> 
    </dependency>  
    <dependency> 
      <groupId>org.slf4j</groupId>  
      <artifactId>slf4j-api</artifactId>  
      <version>1.7.6</version> 
    </dependency>  
    <dependency> 
      <groupId>org.slf4j</groupId>  
      <artifactId>slf4j-jdk14</artifactId>  
      <version>1.7.6</version> 
    </dependency>  
    <dependency> 
      <groupId>junit</groupId>  
      <artifactId>junit</artifactId>  
      <version>3.8.1</version>  
      <scope>test</scope> 
    </dependency>  
    <dependency> 
      <groupId>mysql</groupId>  
      <artifactId>mysql-connector-java</artifactId>  
      <version>5.1.38</version> 
    </dependency> 
  </dependencies>  

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3、 Install the drawing plug-in , This operation is relatively simple , Baidu can receive , Offline installation is recommended A little ........... 4、activity It is a complete system , Various operations and database tables are provided by the framework itself , So the first step is to import ativity Table structure required stay resources Under the new activiti.cfg.xml file ：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
                http://www.springframework.org/schema/beans/spring-beans.xsd">
	<bean id="processEngineConfiguration" class="org.activiti.engine.impl.cfg.StandaloneInMemProcessEngineConfiguration">
        <property name="databaseSchemaUpdate" value="true"/>
		<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/activiti"/>
        <property name="jdbcDriver" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUsername" value="root" />
        <property name="jdbcPassword" value="root" />
    </bean>
</beans>

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Create a new one java class 【CreateTable.java】

package com.test.activity.TestActi;

import org.activiti.engine.ProcessEngine;
import org.activiti.engine.ProcessEngineConfiguration;

public class CreateTable {
	 
	  public static void main(String args[]){
	 
	      ProcessEngine processEngine = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource("activiti.cfg.xml")
	 
	              .buildProcessEngine();
	 
	      System.out.println("processEngine="+processEngine);
	 
	  }
}

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Then the run will appear in the database as follows ：

With the drawing plug-in and the table structure of the database , Even if the basic environment is built .

4、 Introduction case writing First step ： Draw flow chart . Flow chart is the core operation , The later data trend will be transferred according to the flow chart . Take the reimbursement form as an example ：

Pay attention when drawing , Load several modules in advance

properties Can pass window—showview Load it out , On the right is the drawing control , We all need 4 Nodes StartEvent ： Start events

Select the icon and drag it to the left blank

Then click the arrow icon on the right , It means adding a new user task [UserTask],

Similarly, add manager approval in turn 、 Financial approval 、 End the event

Then modify the attributes of each module （properties）：

Then save the flowchart , The drawing is complete . Be careful , The arrow path is the data flow . Here's the picture ：

* Note here ：* If there is no picture generated after saving , You need to start a configuration , Then save again

5、 Write code , Release 、 start-up 、 Query task 、 Processing tasks

  /**
	 *  Deployment process 
	 */
	private static ProcessEngine processEngine =ProcessEngines.getDefaultProcessEngine();
	 
	    public void delployFlow(){
	                 Deployment deployment = processEngine.getRepositoryService()
	                .createDeployment()
	                .name(" Reimbursement process ")	// Process name 
	                .addClasspathResource("baoxiao.bpmn")
	                .addClasspathResource("baoxiao.png")
	                .deploy();
	        
	        //  Exist in the database  act_re_procdef Of DEPLOYMENT_ID_
	        System.out.println(deployment.getId());
	        System.out.println(deployment.getName());
	   }

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It's easy to run , Build your own main Method: just run OK, give the result as follows ：

View the database after deployment

Pay attention to key value ： The next step is to use it 【 This is because demo, So we don't query the database , Direct value operation to view the effect 】

Start process code ：

        //  Start process 
	    public void flowStart(){
	        RuntimeService runtimeService = processEngine.getRuntimeService();
	        // use key When starting, start according to the latest version of the flowchart   [ Database table =act_re_procdef In the process definition table KEY_ Field ]
	        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey(" Employee reimbursement documents ");
	 
	    }

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Check the database after running the code act_ru_task surface The position of the red box indicates the node information

We're looking for employe The task of ：

  public void findEmployeeTask(){
	    	// Database relationships 》》》》ID【act_re_deployment】 == ID【act_ru_execution】  == ID【act_ru_task】 ==》【ASSIGNEE_(cwh)】
	        String assignee = "employee";  // Node assignee_
	        List<Task> taskList= processEngine.getTaskService()// Access to task service
	                .createTaskQuery()// Create query object 
	                .taskAssignee(assignee)// Specify the inquirer 
	                .list();
	        
	        if(taskList.size()>0){
	            for (Task task : taskList){
	                System.out.println(" To act as an agent ID:"+task.getId());
	                System.out.println(" To act as an agent name:"+task.getName());
	                System.out.println(" Creation time of the delegated task :"+task.getCreateTime());
	                System.out.println(" Agent task handler :"+task.getAssignee());
	                System.out.println(" Process instance ID:"+task.getProcessInstanceId());
	                System.out.println(" Perform object ID:"+task.getExecutionId());
	            }
	        }
	    }

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We found out employee The next one is 5004 Your task is waiting to be processed , We deal directly with

 /**
	     *  Processing flow 
	     * 
	     * @Description:
	     */
	    public void completeTask(){
	    	// ID【act_ru_task】
	        String taskId = "5004";        
	        processEngine.getTaskService().complete(taskId);// To complete the task 
	 
	        System.out.println(" To complete the task , Mission ID"+taskId);
	 
	  }

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Then check the database effect

Obviously , Process from employee Transferred to manager below , Of course, this process will be clearer if you analyze it yourself ,,

The process only needs to see ru Related tables , This is the task information table being processed . Do not participate in recording data before processing ,

The rest is Repeat the operation .. 1、 Get the agent process of the manager – Processing flow 2、 Get the agency process of finance – Processing flow – End of the process

This is just a very simple initial demo, But we can basically figure it out activity Operation process and execution logic . And will probably apply to those scene . As for the follow-up , You can view documents or other materials to learn according to your needs .

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