将JBPM4整合到web工程---流程实例管理

1.将上一篇“将JBPM4整合到web工程”项目拷贝一份

2.修改index.jsp文件至如下，在现实流程定义里面增加两个操作“启动流程，查看流程”。同时增加一个用来显示流程实例的table,并添加一个“执行”的操作。

<%@page contentType="text/html;charset=UTF-8" %>
<%@page import="org.jbpm.api.*" %>
<%@page import="java.util.*" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>



        jBPM4学习


        "jbpm?zzg=deploy" method="post">
            "xml" cols=50 rows=15>
            "submit" value="发布"/>
            "reset" value="取消"/>


        480 border=1>
            "5">流程定义

                ID
                Key
                名称
                版本
                操作

            "process" items="${process}">

                ${process.id}
                ${process.key}
                ${process.name}
                ${process.version}
                "jbpm?zzg=start&key=${process.key }">启动
                "jbpm?zzg=query&id=${process.id }">查看
                "jbpm?zzg=delete&id=${process.id }">删除






        480 border=1>
            "5">流程实例

                ID
                Key
                状态
                操作

            "pi" items="${pi}">

                ${pi.id}
                ${pi.key}
                ${pi.state}
                "jbpm?zzg=run&pid=${pi.id }">执行

3.然后修改至JbpmServlet.java文件如下

package zzg;

import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.jbpm.api.Configuration;
import org.jbpm.api.ExecutionService;
import org.jbpm.api.ProcessDefinition;
import org.jbpm.api.ProcessDefinitionQuery;
import org.jbpm.api.ProcessEngine;
import org.jbpm.api.ProcessInstance;
import org.jbpm.api.RepositoryService;

public class JbpmServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private ProcessEngine processEngine = null;
    private RepositoryService repositoryService = null;
    private ExecutionService executionService = null;
    private ProcessInstance processInstance = null;

    /* 初始化ProcessEngine. */
    public void init(ServletConfig config) throws ServletException {
        processEngine = new Configuration().buildProcessEngine();
        repositoryService = processEngine.getRepositoryService();
        executionService = processEngine.getExecutionService();
    }

    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        process(request, response);
    }

    protected void doPost(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        process(request, response);
    }

    protected void process(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String zzg = request.getParameter("zzg");
        List pi = null;
        if (zzg.equals("deploy")) {
            deployProcessDefinition(request, response);
        } else if (zzg.equals("delete")) {
            removeProcessDefinitionById(request, response);
        } else if (zzg.equals("start")) {
            startProcessInstance(request, response);
        } else if (zzg.equals("query")) {
            pi = getProcessInstance(request, response);
            request.setAttribute("pi", pi);
        } else if (zzg.equals("run")) {
            signalProcessInstance(request, response);
            pi = getProcessInstance(request, response);
            request.setAttribute("pi", pi);
        }
        List list = getLatestProcessDefinition(request,
                response);
        request.setAttribute("process", list);
        request.getRequestDispatcher("/index.jsp").forward(request, response);
    }

    /**
     * 发布流程方法
     *
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    protected void deployProcessDefinition(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String xml = request.getParameter("xml");
        repositoryService.createDeployment().addResourceFromString(
                "yy.jpdl.xml", xml).deploy();
    }

    /* 获取最新流程. */
    protected List getLatestProcessDefinition(
            HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // 获取全部的流程定义
        List processDefinitions = repositoryService
                .createProcessDefinitionQuery().orderAsc(
                        ProcessDefinitionQuery.PROPERTY_NAME).list();

        Map map = new LinkedHashMap();
        for (ProcessDefinition pd : processDefinitions) {
            String key = pd.getKey();
            ProcessDefinition definition = map.get(key);
            if ((definition == null)
                    || (definition.getVersion() < pd.getVersion())) {
                map.put(key, pd);
            }
        }
        return new ArrayList(map.values());
    }

    /* 删除流程定义. */
    protected void removeProcessDefinitionById(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String id = request.getParameter("id");
        // 根据流程ID获取流程定义实例
        ProcessDefinition pd = repositoryService.createProcessDefinitionQuery()
                .processDefinitionId(id).uniqueResult();
        // 根据流程定义发布的ID来删除流程定义
        // 注意:jbpm4是不允许直接根据流程定义的ID来直接删除流程定义的
        repositoryService.deleteDeploymentCascade(pd.getDeploymentId());
    }

    /* 根据流程定义的key值启动流程. */
    protected void startProcessInstance(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String key = request.getParameter("key");
        processInstance = executionService.startProcessInstanceByKey(key);
    }

    /* 根据流程定义的ID查询流程实例. */
    protected List getProcessInstance(
            HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String pdId = request.getParameter("id");
        return executionService.createProcessInstanceQuery()
                .processDefinitionId(pdId).list();
    }

    /* 根据流程实例的ID执行流程实例. */
    protected void signalProcessInstance(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        String pid = request.getParameter("pid");
        executionService.signalExecutionById(pid);
    }
}

4.控制流程的活动主要包括以下几个：

• Start 启动流程
• End 结束流程
• State 流程等待
• Decision 决定流程流向
• Task 等待
• Fork 流程分支
• Join 流程汇聚
• Custom 操作流程
• Sub-process 启动一个子流程