beanshellfunctionprovider.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.beanshell;

import bsh.EvalError;
import bsh.Interpreter;
import bsh.TargetError;

import com.opensymphony.module.propertyset.PropertySet;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.Map;


/**
 *
 *
 * @author Hani
 */
public class BeanShellFunctionProvider implements FunctionProvider {
    //~ Static fields/initializers /////////////////////////////////////////////

    private static final Log log = LogFactory.getLog(BeanShellFunctionProvider.class);

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

    public void execute(Map transientVars, Map args, PropertySet ps) throws WorkflowException {
        String script = (String) args.get(AbstractWorkflow.BSH_SCRIPT);
        Interpreter i = null;
        ClassLoader loader = null;
        WorkflowContext context = (WorkflowContext) transientVars.get("context");
        WorkflowEntry entry = (WorkflowEntry) transientVars.get("entry");
        loader = Thread.currentThread().getContextClassLoader();

        try {
            i = new Interpreter();

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

            i.set("entry", entry);
            i.set("context", context);
            i.set("transientVars", transientVars);
            i.set("propertySet", ps);
        } catch (EvalError evalError) {
            String message = "Could not set values for BSH script";
            log.error(message, evalError);
            throw new WorkflowException(message, evalError);
        }

        try {
            i.eval(script);
        } catch (TargetError targetError) {
            if (targetError.getTarget() instanceof WorkflowException) {
                throw (WorkflowException) targetError.getTarget();
            } else {
                String message = "Evaluation error while running BSH function script";
                throw new WorkflowException(message, targetError.getTarget());
            }
        } catch (EvalError evalError) {
            String message = "Evaluation error while running BSH function script";
            log.error(message, evalError);
            throw new WorkflowException(message, evalError);
        } finally {
            if (loader != null) {
                i.setClassLoader(null);
            }
        }
    }
}