xsltransformactivity.java

来自「使用spring构建一个简单的工作流引擎」· Java 代码 · 共 81 行

package org.iocworkflow.support;

import java.io.StringWriter;
import java.net.URL;

import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.iocworkflow.BaseActivity;
import org.iocworkflow.ProcessContext;
import org.springframework.util.ResourceUtils;

/**
 * Class:XslTransformActivity Creation Date: Mar 12, 2005 CVS ID $Id:$
 * 
 * Class Descriptoin goes here
 * 
 * @author sdodge
 * @since $Date:$
 */
public class XslTransformActivity extends BaseActivity {

    private String xslLocation;
    private Log log = LogFactory.getLog(XslTransformActivity.class);

    /*
     * (non-Javadoc)
     * 
     * @see org.iocworkflow.Activity#execute(org.iocworkflow.ProcessContext)
     */
    public ProcessContext execute(ProcessContext context) throws Exception {

        XsltAware xslContext = (XsltAware) context;
        URL xslUrl = ResourceUtils.getURL(xslLocation);
        
        log.debug("About to apply XSL transform");
        String transData = applyTransform(getXslSource(xslUrl),xslContext.getDomSource());
        xslContext.setTransformedContent(transData);
        log.debug("Transformed content:");
        log.debug(transData);

        return (ProcessContext)xslContext;
    }

    private Source getXslSource(URL url) {
        //use the URL object to get an Extrenal Stirng url e.g. file///usr/local ... etc
        String xslSysId = url.toExternalForm();
        log.debug(" Found xsl file in filesystem " + xslSysId);
        StreamSource xslSource = new StreamSource(xslSysId);

        return xslSource;
    }

    private static String applyTransform(Source xslSource, Source xmlSource) throws Exception {
        StringWriter sWriter = new StringWriter();
        StreamResult sResult = new StreamResult(sWriter);
        getXFormResult(xslSource, xmlSource, sResult);
        return sWriter.toString();
    }

    private static void getXFormResult(Source xslSource, Source xmlSource, Result result) throws Exception {
        TransformerFactory factory = null;
        Transformer xformer = null;

        factory = TransformerFactory.newInstance();
        xformer = factory.newTransformer(xslSource);
        xformer.transform(xmlSource, result);

    }

    public void setXslLocation(String xslLocation) {
        this.xslLocation = xslLocation;
    }
}