CopyCompiledGwtResourcesMain.java

/**
 * Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
 *
 * 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 org.onebusaway.presentation.impl;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.xml.namespace.QName;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class CopyCompiledGwtResourcesMain {

  private static final Pattern _pattern = Pattern.compile("\\$\\{([^}]+)\\}");

  public static void main(String[] args) throws Exception {

    if (args.length != 1) {
      System.err.println("usage: webapp-target-dir");
      System.exit(-1);
    }

    File pomFile = new File("pom.xml");
    File webappDirectory = new File(args[0]);

    if (!pomFile.exists()) {
      System.err.println("ERROR - didn't find the pom file where we expected it: "
          + pomFile.getAbsolutePath());
      System.exit(-1);
    }

    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = docFactory.newDocumentBuilder();

    Document doc = builder.parse(pomFile);

    String expression = "project/build/plugins/plugin[artifactId='maven-war-plugin']/configuration/webResources/resource";
    NodeList nodes = xpath(doc, expression, NodeList.class);

    for (int i = 0; i < nodes.getLength(); i++) {
      Node resourceNode = nodes.item(i);
      Node directoryNode = xpath(resourceNode, "directory", Node.class);
      Node targetPathNode = xpath(resourceNode, "targetPath", Node.class);
      String directory = directoryNode.getTextContent();
      String targetPath = targetPathNode.getTextContent();

      directory = resolveValue(directory);

      System.out.println("directory=" + directory);
      System.out.println("targetPath=" + targetPath);
      copyFiles(new File(directory), new File(webappDirectory, targetPath));
    }
  }

  private static String resolveValue(String value) {
    Matcher m = _pattern.matcher(value);
    StringBuffer sb = new StringBuffer();
    while (m.find()) {
      String property = m.group(1);
      String propertyValue = System.getProperty(property);
      if (propertyValue == null && property.equals("project.build.directory")) {
        propertyValue = "target";
      } else {
        propertyValue = resolveValue(propertyValue);
      }
      m.appendReplacement(sb, propertyValue);
    }
    m.appendTail(sb);
    return sb.toString();
  }

  private static void copyFiles(File sourceDirectory, File targetDirectory)
      throws IOException {

    if (!(sourceDirectory.exists() && sourceDirectory.isDirectory()))
      return;

    if (!targetDirectory.exists())
      targetDirectory.mkdirs();

    File[] files = sourceDirectory.listFiles();
    if (files == null)
      return;
    for (File file : files) {
      File targetFile = new File(targetDirectory, file.getName());
      if (!targetFile.exists()
          || file.lastModified() > targetFile.lastModified())
        if (file.isDirectory())
          copyFiles(file, targetFile);
        else
          copyFile(file, targetFile);
    }
  }

  private static void copyFile(File srcFile, File dstFile) throws IOException {
    System.out.println("from=" + srcFile.getAbsolutePath());
    System.out.println("to=" + dstFile.getAbsolutePath());
    InputStream in = new BufferedInputStream(new FileInputStream(srcFile));
    OutputStream out = new BufferedOutputStream(new FileOutputStream(dstFile));
    byte[] buffer = new byte[1024];
    while (true) {
      int rc = in.read(buffer);
      if (rc == -1)
        break;
      if (rc > 0)
        out.write(buffer, 0, rc);
    }
    in.close();
    out.close();
  }

  @SuppressWarnings("unchecked")
  private static <T> T xpath(Node node, String expression, Class<T> type)
      throws XPathExpressionException {
    XPathFactory xpathFactory = XPathFactory.newInstance();
    XPath xpath = xpathFactory.newXPath();
    XPathExpression expr = xpath.compile(expression);

    QName returnType = null;
    if (type == NodeList.class)
      returnType = XPathConstants.NODESET;
    else if (type == Node.class)
      returnType = XPathConstants.NODE;
    else
      throw new IllegalStateException("unknown return type " + type);
    return (T) expr.evaluate(node, returnType);
  }
}