bsfregister.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.util.bsf;

import com.opensymphony.module.propertyset.PropertySet;

import com.opensymphony.util.TextUtils;

import com.opensymphony.workflow.*;
import com.opensymphony.workflow.spi.WorkflowEntry;

import org.apache.bsf.BSFEngine;
import org.apache.bsf.BSFException;
import org.apache.bsf.BSFManager;

import java.util.Map;


/**
 * Register that invokes a BSF script.
 * args parameter is expected to contain the follow arguments:
 *
 * <li>{@link AbstractWorkflow#BSF_LANGUAGE}: The language of the script
 * <li>{@link AbstractWorkflow#BSF_SOURCE}: The source of the script
 * <li>{@link AbstractWorkflow#BSF_ROW}: The row of the script
 * <li>{@link AbstractWorkflow#BSF_COL}: The column of the script
 *
 * @author $Author: hani $
 * @version $Revision: 1.4 $
 */
public class BSFRegister implements Register {
    //~ Methods ////////////////////////////////////////////////////////////////

    public Object registerVariable(WorkflowContext context, WorkflowEntry entry, Map args, PropertySet ps) throws WorkflowException {
        String language = (String) args.get(AbstractWorkflow.BSF_LANGUAGE);
        String source = (String) args.get(AbstractWorkflow.BSF_SOURCE);
        int row = TextUtils.parseInt((String) args.get(AbstractWorkflow.BSF_ROW));
        int col = TextUtils.parseInt((String) args.get(AbstractWorkflow.BSF_COL));
        String script = (String) args.get(AbstractWorkflow.BSF_SCRIPT);

        BSFManager mgr = new BSFManager();
        ClassLoader loader = Thread.currentThread().getContextClassLoader();

        if (loader != null) {
            mgr.setClassLoader(loader);
        }

        mgr.registerBean("propertySet", ps);
        mgr.registerBean("entry", entry);
        mgr.registerBean("context", context);

        try {
            BSFEngine engine = mgr.loadScriptingEngine(language);

            return engine.eval(source, row, col, script);
        } catch (BSFException e) {
            String message = "Could not get object registered in to variable map";
            throw new WorkflowException(message, e);
        }
    }
}