com.collabnet.ccf.schemageneration.XSLTInitialMFDGeneratorScriptGenerator.java Source code

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Here is the source code for com.collabnet.ccf.schemageneration.XSLTInitialMFDGeneratorScriptGenerator.java

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/*
 * Copyright 2009 CollabNet, Inc. ("CollabNet")
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **/

package com.collabnet.ccf.schemageneration;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamSource;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.io.DocumentResult;
import org.dom4j.io.DocumentSource;

import com.collabnet.ccf.core.CCFRuntimeException;

/**
 * This component will apply an XSLT script on an exiting 
 * MFD document to produce an XSLT script that can be used
 * as input for the XSLTInitialMFDGenerator
 * 
 * @author jnicolai
 * 
 */
public class XSLTInitialMFDGeneratorScriptGenerator {

    public final static String INITIAL_MFD_XSLT_FILE = "xslt/CreateCreateInitialMFD.xsl";

    private Transformer initialMFDFileTransformer = null;

    public XSLTInitialMFDGeneratorScriptGenerator() {
        initialMFDFileTransformer = loadXSLT(INITIAL_MFD_XSLT_FILE);
    }

    /**
     * Applies the transform to the Dom4J document
     * 
     * @param transformer
     * @param d
     *            the document to transform
     * @param targetSchemaName 
     * @param sourceSchemaName 
     * 
     * @return an array containing a single XML string representing the
     *         transformed document
     * @throws TransformerException
     *             thrown if an XSLT runtime error happens during transformation
     */
    private static Document transform(Transformer transformer, Document d, String sourceSchemaName,
            String targetSchemaName) throws TransformerException {
        DocumentSource source = new DocumentSource(d);
        DocumentResult result = new DocumentResult();
        transformer.setParameter("sourceSchema", sourceSchemaName);
        transformer.setParameter("targetSchema", targetSchemaName);
        transformer.transform(source, result);
        return result.getDocument();
    }

    /**
     * Creates a new CreateInitialMFD.xsl file based on an already existing MFD file
     * @param mfdTemplateFile path to mfdFile
     * @param targetSchemaName 
     * @param sourceSchemaName 
     * @return XML document containing CreateInitialMFD XSLT script
     * @throws TransformerException
     * @throws IOException 
     * @throws DocumentException
     */
    public Document generateCreateInitialMFDScript(String mfdTemplateFile, String sourceSchemaName,
            String targetSchemaName) throws TransformerException, DocumentException, IOException {
        Document document = DocumentHelper.parseText(readFileAsString(mfdTemplateFile));
        return transform(initialMFDFileTransformer, document, sourceSchemaName, targetSchemaName);
    }

    private static String readFileAsString(String filePath) throws java.io.IOException {
        StringBuffer fileData = new StringBuffer(1000);
        BufferedReader reader = new BufferedReader(new FileReader(filePath));
        char[] buf = new char[1024];
        int numRead = 0;
        while ((numRead = reader.read(buf)) != -1) {
            fileData.append(buf, 0, numRead);
        }
        reader.close();
        return fileData.toString();
    }

    /**
     * Loads XSLT files and builds transformer
     */
    private static Transformer loadXSLT(String xsltFile) {
        Transformer transform = null;
        InputStream inputStream = null;

        inputStream = XSLTInitialMFDGeneratorScriptGenerator.class.getResourceAsStream("/" + xsltFile);
        // load the transform
        try {
            TransformerFactory factory = TransformerFactory.newInstance();
            StreamSource streamSource = new StreamSource(inputStream);
            transform = factory.newTransformer(streamSource);

            // log.debug("Loaded XSLT [" + xsltFile + "] successfully");
        } catch (TransformerConfigurationException e) {
            throw new CCFRuntimeException("Could not load XSLT file " + xsltFile + ": " + e.getMessage(), e);
        }
        return transform;
    }
}