将JBPM4整合到web工程---流程实例管理

最新推荐文章于 2024-08-29 15:58:48 发布

最新推荐文章于 2024-08-29 15:58:48 发布 · 111 阅读

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#Web #项目管理 #JBPM #Java #Servlet

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本文介绍了如何在Web项目中整合JBPM4流程引擎，并详细展示了如何通过修改index.jsp文件来实现流程定义的操作如启动、查看及流程实例的展示。此外，还提供了JbpmServlet.java的具体代码实现。

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"%>

<html>
	<head>
		<title>jBPM4学习</title>
	</head>
	<body>
	  	<form action="jbpm?zzg=deploy" method="post">
	  		<textarea name="xml" cols=50 rows=15></textarea>
	  		<input type="submit" value="发布"/>
	  		<input type="reset" value="取消"/>
	  	</form>

	  	<table width=480 border=1>
	  	    <tr><td colspan="5">流程定义</td></tr>
			<tr>
				<td>ID</td>
				<td>Key</td>
				<td>名称</td>
				<td>版本</td>
				<td>操作</td>
			</tr>
			<c:forEach var="process" items="${process}">
			<tr>
				<td>${process.id}</td>
				<td>${process.key}</td>
				<td>${process.name}</td>
				<td>${process.version}</td>
				<td><a href="jbpm?zzg=start&key=${process.key }">启动</a>
				<a href="jbpm?zzg=query&id=${process.id }">查看</a>
				<a href="jbpm?zzg=delete&id=${process.id }">删除</a></td>
			</tr>
			</c:forEach>
		</table>
		<br>
		<br>
		<br>
		<table width=480 border=1>
	  	    <tr><td colspan="5">流程实例</td></tr>
			<tr>
				<td>ID</td>
				<td>Key</td>
				<td>状态</td>
				<td>操作</td>
			</tr>
			<c:forEach var="pi" items="${pi}">
			<tr>
				<td>${pi.id}</td>
				<td>${pi.key}</td>
				<td>${pi.state}</td>
				<td><a href="jbpm?zzg=run&pid=${pi.id }">执行</a></td>
			</tr>
			</c:forEach>
		</table>
	</body>
</html>

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<ProcessInstance> 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<ProcessDefinition> 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<ProcessDefinition> getLatestProcessDefinition(
			HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// 获取全部的流程定义
		List<ProcessDefinition> processDefinitions = repositoryService
				.createProcessDefinitionQuery().orderAsc(
						ProcessDefinitionQuery.PROPERTY_NAME).list();

		Map<String, ProcessDefinition> map = new LinkedHashMap<String, ProcessDefinition>();
		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<ProcessInstance> 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：
[list]
[*]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
[/list]