AbstractHttpXmlEncoder.java

/*
 * Copyright 2013-2018 Lilinfeng.
 *  
 * 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.phei.netty.protocol.http.xml.codec;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.MessageToMessageEncoder;

import java.io.StringWriter;
import java.nio.charset.Charset;

import org.jibx.runtime.BindingDirectory;
import org.jibx.runtime.IBindingFactory;
import org.jibx.runtime.IMarshallingContext;

/**
 * @author Administrator
 * @date 2014年3月1日
 * @version 1.0
 */
public abstract class AbstractHttpXmlEncoder<T> extends
	MessageToMessageEncoder<T> {
    IBindingFactory factory = null;
    StringWriter writer = null;
    final static String CHARSET_NAME = "UTF-8";
    final static Charset UTF_8 = Charset.forName(CHARSET_NAME);

    protected ByteBuf encode0(ChannelHandlerContext ctx, Object body)
	    throws Exception {
	factory = BindingDirectory.getFactory(body.getClass());
	writer = new StringWriter();
	IMarshallingContext mctx = factory.createMarshallingContext();
	mctx.setIndent(2);
	mctx.marshalDocument(body, CHARSET_NAME, null, writer);
	String xmlStr = writer.toString();
	writer.close();
	writer = null;
	ByteBuf encodeBuf = Unpooled.copiedBuffer(xmlStr, UTF_8);
	return encodeBuf;
    }

    /**
     * Calls {@link ChannelHandlerContext#fireExceptionCaught(Throwable)} to
     * forward to the next {@link ChannelHandler} in the {@link ChannelPipeline}
     * .
     * 
     * Sub-classes may override this method to change behavior.
     */
    @Skip
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
	    throws Exception {
	// 释放资源
	if (writer != null) {
	    writer.close();
	    writer = null;
	}
    }

}