[activiti] process example

Process instance

1. What is a process instance

** Process instance (ProcessInstance)** Represents the execution instance of the process definition .

A process instance contains all the running nodes . We can use this object to understand the progress of the current process instance .

for example ： User or program according to Process definition Content initiates a process , It's just one. Process instance

Diagram of process definition and process instance ：

2. Start process instance

After the process definition is deployed , You can go through activiti To manage the execution of the process , An execution process represents an execution of a process .

For example, after deploying the travel process , A user who applies for a business trip needs to implement this business trip process , Another user can also execute this business trip process , The two process instances do not affect each other , Each execution is a separate process instance .

When starting a process instance , Appoint businessKey, Will be in act_ru_exection Table storage businessKey

BusinessKey： Business identification , It is usually the primary key of the business table , The business ID corresponds to the process instance . The business ID comes from the business system , The stored business ID is used to query business system data .

such as ： Start a business trip process instance , You can send the business trip application form id Save as business ID to activiti in , Future queries activiti Process instance information , You can find out the business identification , So as to query the detailed information of the business trip form in the business system .

2.1 Start the process instance code

    /** *  Boot instance , Add business ID businessKey */
    @Test
    public void addBusinessKey() {
    
        // obtain processEngine
        ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
        // obtain runtimeService
        RuntimeService runtimeService = processEngine.getRuntimeService();
        /** *  Boot instance , At the same time, specify the business ID businessKey * startProcessInstanceByKey(String processDefinitionKey, String businessKey) * processDefinitionKey： Process defined key * businessKey： Business identification , Input according to business parameters  */
        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("evection", "1001");
        // Output the business ID in the process instance information 
        System.out.println(" Business identification ：" + processInstance.getBusinessKey());
    }

2.2 Description of start process instance operation table

Start process instance , The operation table is as follows ：

Process instance execution table , Record the execution of the current process instance , A process instance is running , The process instance related records of this table will also be deleted .

There will always be a record's primary key in this table id And process instances id identical .

Task participant table , Record the users or groups currently participating in the task

Process instance history table

Process start , A record will be inserted in this table , The process instance will not be deleted after running .

Task history table , Record all tasks

Start a mission , Not only in act_ru_task Table insert record , A record will also be inserted in the historical task table , The primary key of the task history table is the task id, When the task is completed, the record in this table will not be deleted .

Activity history table , Record all activities

Activities include tasks , So this table not only records the tasks , Other activities during the process execution are also recorded , Like the start event 、 End the event .

3. Query process instance

The status of process instances can be queried during process running , Current operation node and other information

    /** *  Query process instance  */
    @Test
    public void queryTaskProcess() {
    
        // Process definition key
        String processDefinitionKey = "evection";
        // obtain ProcessEngine
        ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
        // obtain runtimeService
        RuntimeService runtimeService = processEngine.getRuntimeService();
        // Get process instance 
        List<ProcessInstance> instanceList = runtimeService
                .createProcessInstanceQuery()
                .processDefinitionKey(processDefinitionKey)
                .list();
        instanceList.forEach(instance -> {
    
            System.out.println("========================");
            System.out.println(" Process instance id：" + instance.getId());
            System.out.println(" Process definition id：" + instance.getProcessDefinitionId());
            System.out.println(" Execution completed ：" + instance.isEnded());
            System.out.println(" Whether to suspend ：" + instance.isSuspended());
            System.out.println(" Current activity id id：" + instance.getActivityId());
        });
    }

4. relation BusinessKey

demand ：

stay activiti In practice , When querying the process instance list, you may want to display some relevant information of the business system , such as ： To query the list of currently running travel processes, you need to list the name of the travel form 、 Travel days and other information , The business system defines the business trip days and other information , Exist in the business system , Not in activiti In the database , So I can't get through activiti You can find the travel days .

Realization ：

When querying process instances , adopt businessKey（ Business identification ） The travel document table of the associated query business system , Query the travel days and other information . But the premise is , When starting a process instance , Need to put businessKey Store in activiti in , Generally, the primary key of the related business operation table id.

add to businessKey The way is ：

ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("evection", "1001");

Then you can start from activiti In order to get businessKey, Re pass businessKey Get the data in the corresponding business table .

obtain businessKey The way is ：

String businessKey = processInstance.getBusinessKey();

stay activiti Of act_ru_execution In the table , Field BUSINESS_KEY Is to store business KEY Of

5. Hang up / Activate process instances

In some cases , Due to process changes, the currently running process needs to be suspended rather than deleted , You need to pause the process , No more execution .

5.1 All process instances are suspended / Activate

The operation flow is defined as pending status , All process instances under the process definition are suspended .

The process is defined as suspended , The process definition will not allow you to start a new process instance , At the same time, all process instances under the process definition will be suspended and suspended , Completing the process instance under the process definition will throw an exception

    /** *  All process instances are suspended ===》 Directly suspend the corresponding process definition , All process instances under the process definition are suspended  *  All process instances are suspended and activated ===》 Activate the corresponding process definition directly , All process instances under the process definition are activated  */
    @Test
    public void suspendAllProcessInstance() {
    
        // obtain processEngine
        ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
        // obtain RepositoryService
        RepositoryService repositoryService = processEngine.getRepositoryService();
        // Query the process definition object 
        ProcessDefinition processDefinition = repositoryService
                .createProcessDefinitionQuery()
                .processDefinitionKey("evection")
                .singleResult();
        // Get whether the current process definition is in suspended status 
        boolean suspended = processDefinition.isSuspended();
        // Process definition id
        String processDefinitionId = processDefinition.getId();
        // Determine whether to suspend 
        if (suspended) {
    
            // If it's suspended , Perform activation 
            // Parameters 1： Process definition id  Parameters 2： Whether to activate   Parameters 3： Activation time 
            repositoryService.activateProcessDefinitionById(processDefinitionId, true, null);
            System.out.println(" Process definition ：" + processDefinitionId + ", Activated ");
        } else {
    
            // If it's active , Perform pending operation 
            // Parameters 1： Process definition id  Parameters 2： Whether to suspend   Parameters 3： Hold time 
            repositoryService.suspendProcessDefinitionById(processDefinitionId, true, null);
            System.out.println(" Process definition ：" + processDefinitionId + ", Suspended ");
        }
    }

5.2 A single process instance is suspended / Activate

Operation process instance object , Execution is suspended for a single process / Activate operation , When a process instance is suspended, the process will not continue , Completing the process instance will throw an exception .

    /** *  A single process instance is suspended and activated  */
    @Test
    public void suspendSingleProcessInstance() {
    
        // obtain processEngine
        ProcessEngine processEngine = ProcessEngines.getDefaultProcessEngine();
        // obtain RuntimeService
        RuntimeService runtimeService = processEngine.getRuntimeService();
        // Query the process instance object 
        ProcessInstance processInstance = runtimeService
                .createProcessInstanceQuery()
                // Process instance id Fill in according to your own data 
                .processInstanceId("30001")
                .singleResult();
        // Get whether the current process instance is in suspended state 
        boolean suspended = processInstance.isSuspended();
        // Process instance id
        String processInstanceId = processInstance.getId();
        // Determine whether to suspend 
        if (suspended) {
    
            // If it's suspended , Perform activation 
            // Parameters 1： Process instance id
            runtimeService.activateProcessInstanceById(processInstanceId);
            System.out.println(" Process instance ：" + processInstanceId + ", Activated ");
        } else {
    
            // If it's active , Execution pending 
            // Parameters 1： Process instance id
            runtimeService.suspendProcessInstanceById(processInstanceId);
            System.out.println(" Process instance ：" + processInstanceId + ", Suspended ");
        }

When a process definition or a process instance is suspended , Completing the process instance will throw an exception .