workflowfactoryservlet.java

一个很好实用的工作流OSWORKFLOW开发例子.有着非常优秀的灵活性.

/*
 * Copyright (c) 2002-2003 by OpenSymphony
 * All rights reserved.
 */
package com.opensymphony.workflow.config;

import com.opensymphony.workflow.FactoryException;
import com.opensymphony.workflow.loader.*;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import java.net.MalformedURLException;
import java.net.URL;

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


/**
 * @author Hani Suleiman Date: Dec 17, 2004 Time: 12:21:44 PM
 */
public class WorkflowFactoryServlet extends HttpServlet {
    //~ Instance fields ////////////////////////////////////////////////////////

    private WorkflowFactory factory;

    //~ Methods ////////////////////////////////////////////////////////////////

    public void init() throws ServletException {
        DefaultConfiguration config = new DefaultConfiguration();
        URL url = null;
        String configFile = getInitParameter("config");

        if (configFile != null) {
            try {
                url = new URL(configFile);
            } catch (MalformedURLException e) {
                try {
                    url = getServletContext().getResource(configFile);
                } catch (MalformedURLException e1) {
                    e1.printStackTrace();
                }
            }
        }

        try {
            config.load(url);
        } catch (FactoryException e) {
            throw new ServletException("Unable to create workflow factory", e);
        }

        this.factory = config.getFactory();
    }

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String command = req.getParameter("command");
        String docId = req.getParameter("docId");

        if ("layout".equals(command)) {
            Object layout = factory.getLayout(docId);

            if (layout != null) {
                resp.setContentType("text/plain");
                resp.getWriter().write(layout.toString());
            }
        } else if ("workflow".equals(command)) {
            try {
                WorkflowDescriptor descriptor = factory.getWorkflow(docId);
                resp.setContentType("text/xml");
                descriptor.writeXML(resp.getWriter(), 0);
            } catch (FactoryException e) {
                e.printStackTrace(resp.getWriter());
                resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            }
        }
    }

    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String command = req.getParameter("command");
        String docId = req.getParameter("docId");
        String data = req.getParameter("data");

        if ("layout".equals(command)) {
            factory.setLayout(docId, data.toString());
        } else if ("workflow".equals(command)) {
            boolean replace = "true".equals(req.getParameter("replace"));

            try {
                WorkflowDescriptor descriptor = WorkflowLoader.load(new ByteArrayInputStream(data.getBytes()), false);
                factory.saveWorkflow(docId, descriptor, replace);
            } catch (Exception e) {
                e.printStackTrace(resp.getWriter());
                resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            }
        }
    }
}