XmlCompressorDirective.java
/*
* Copyright 2009-2022 the original author or authors.
*
* 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.googlecode.htmlcompressor.velocity;
import com.googlecode.htmlcompressor.compressor.XmlCompressor;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.exception.MethodInvocationException;
import org.apache.velocity.exception.TemplateInitException;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.parser.node.Node;
/**
* Velocity directive that compresses an XML content within #compressXml ... #end block. Compression parameters are set
* by default.
*
* @author <a href="mailto:serg472@gmail.com">Sergiy Kovalchuk</a>
*
* @see XmlCompressor
*/
public class XmlCompressorDirective extends Directive {
/** The Constant xmlCompressor. */
private static final XmlCompressor xmlCompressor = new XmlCompressor();
@Override
public String getName() {
return "compressXml";
}
@Override
public int getType() {
return BLOCK;
}
@Override
public void init(RuntimeServices rs, InternalContextAdapter context, Node node) throws TemplateInitException {
super.init(rs, context, node);
log = rs.getLog();
// set compressor properties
xmlCompressor.setEnabled(rs.getBoolean("userdirective.compressXml.enabled", true));
xmlCompressor.setRemoveComments(rs.getBoolean("userdirective.compressXml.removeComments", true));
xmlCompressor.setRemoveIntertagSpaces(rs.getBoolean("userdirective.compressXml.removeIntertagSpaces", true));
}
@Override
public boolean render(InternalContextAdapter context, Writer writer, Node node)
throws IOException, MethodInvocationException {
// render content
StringWriter content = new StringWriter();
node.jjtGetChild(0).render(context, content);
// compress
try {
writer.write(xmlCompressor.compress(content.toString()));
} catch (Exception e) {
writer.write(content.toString());
String msg = "Failed to compress content: " + content.toString();
log.error(msg, e);
throw new RuntimeException(msg, e);
}
return true;
}
}