Java example source code file (AbstractSerializer.java)

This example Java source code file (AbstractSerializer.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

abstractserializer, bytearrayoutputstream, canonicalizer, dom, exception, hashmap, ioexception, namednodemap, node, outputstreamwriter, string, stringbuilder, unsupportedencodingexception, utf\-8, util, xmlencryptionexception

The AbstractSerializer.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.sun.org.apache.xml.internal.security.encryption;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;

import com.sun.org.apache.xml.internal.security.c14n.Canonicalizer;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Converts <code>Strings into Nodes and visa versa.
 *
 * An abstract class for common Serializer functionality
 */
public abstract class AbstractSerializer implements Serializer {

    protected Canonicalizer canon;

    public void setCanonicalizer(Canonicalizer canon) {
        this.canon = canon;
    }

    /**
     * Returns a <code>String representation of the specified
     * <code>Element.
     * <p/>
     * Refer also to comments about setup of format.
     *
     * @param element the <code>Element to serialize.
     * @return the <code>String representation of the serilaized
     *   <code>Element.
     * @throws Exception
     */
    public String serialize(Element element) throws Exception {
        return canonSerialize(element);
    }

    /**
     * Returns a <code>byte[] representation of the specified
     * <code>Element.
     *
     * @param element the <code>Element to serialize.
     * @return the <code>byte[] representation of the serilaized
     *   <code>Element.
     * @throws Exception
     */
    public byte[] serializeToByteArray(Element element) throws Exception {
        return canonSerializeToByteArray(element);
    }

    /**
     * Returns a <code>String representation of the specified
     * <code>NodeList.
     * <p/>
     * This is a special case because the NodeList may represent a
     * <code>DocumentFragment. A document fragment may be a
     * non-valid XML document (refer to appropriate description of
     * W3C) because it my start with a non-element node, e.g. a text
     * node.
     * <p/>
     * The methods first converts the node list into a document fragment.
     * Special care is taken to not destroy the current document, thus
     * the method clones the nodes (deep cloning) before it appends
     * them to the document fragment.
     * <p/>
     * Refer also to comments about setup of format.
     *
     * @param content the <code>NodeList to serialize.
     * @return the <code>String representation of the serialized
     *   <code>NodeList.
     * @throws Exception
     */
    public String serialize(NodeList content) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);
        canon.notReset();
        for (int i = 0; i < content.getLength(); i++) {
            canon.canonicalizeSubtree(content.item(i));
        }
        String ret = baos.toString("UTF-8");
        baos.reset();
        return ret;
    }

    /**
     * Returns a <code>byte[] representation of the specified
     * <code>NodeList.
     *
     * @param content the <code>NodeList to serialize.
     * @return the <code>byte[] representation of the serialized
     *   <code>NodeList.
     * @throws Exception
     */
    public byte[] serializeToByteArray(NodeList content) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);
        canon.notReset();
        for (int i = 0; i < content.getLength(); i++) {
            canon.canonicalizeSubtree(content.item(i));
        }
        return baos.toByteArray();
    }

    /**
     * Use the Canonicalizer to serialize the node
     * @param node
     * @return the canonicalization of the node
     * @throws Exception
     */
    public String canonSerialize(Node node) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);
        canon.notReset();
        canon.canonicalizeSubtree(node);
        String ret = baos.toString("UTF-8");
        baos.reset();
        return ret;
    }

    /**
     * Use the Canonicalizer to serialize the node
     * @param node
     * @return the (byte[]) canonicalization of the node
     * @throws Exception
     */
    public byte[] canonSerializeToByteArray(Node node) throws Exception {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        canon.setWriter(baos);
        canon.notReset();
        canon.canonicalizeSubtree(node);
        return baos.toByteArray();
    }

    /**
     * @param source
     * @param ctx
     * @return the Node resulting from the parse of the source
     * @throws XMLEncryptionException
     */
    public abstract Node deserialize(String source, Node ctx) throws XMLEncryptionException;

    /**
     * @param source
     * @param ctx
     * @return the Node resulting from the parse of the source
     * @throws XMLEncryptionException
     */
    public abstract Node deserialize(byte[] source, Node ctx) throws XMLEncryptionException;

    protected static byte[] createContext(byte[] source, Node ctx) throws XMLEncryptionException {
        // Create the context to parse the document against
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        try {
            OutputStreamWriter outputStreamWriter = new OutputStreamWriter(byteArrayOutputStream, "UTF-8");
            outputStreamWriter.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>();
            Node wk = ctx;
            while (wk != null) {
                NamedNodeMap atts = wk.getAttributes();
                if (atts != null) {
                    for (int i = 0; i < atts.getLength(); ++i) {
                        Node att = atts.item(i);
                        String nodeName = att.getNodeName();
                        if ((nodeName.equals("xmlns") || nodeName.startsWith("xmlns:"))
                                && !storedNamespaces.containsKey(att.getNodeName())) {
                            outputStreamWriter.write(" ");
                            outputStreamWriter.write(nodeName);
                            outputStreamWriter.write("=\"");
                            outputStreamWriter.write(att.getNodeValue());
                            outputStreamWriter.write("\"");
                            storedNamespaces.put(nodeName, att.getNodeValue());
                        }
                    }
                }
                wk = wk.getParentNode();
            }
            outputStreamWriter.write(">");
            outputStreamWriter.flush();
            byteArrayOutputStream.write(source);

            outputStreamWriter.write("</dummy>");
            outputStreamWriter.close();

            return byteArrayOutputStream.toByteArray();
        } catch (UnsupportedEncodingException e) {
            throw new XMLEncryptionException("empty", e);
        } catch (IOException e) {
            throw new XMLEncryptionException("empty", e);
        }
    }

    protected static String createContext(String source, Node ctx) {
        // Create the context to parse the document against
        StringBuilder sb = new StringBuilder();
        sb.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>();
        Node wk = ctx;
        while (wk != null) {
            NamedNodeMap atts = wk.getAttributes();
            if (atts != null) {
                for (int i = 0; i < atts.getLength(); ++i) {
                    Node att = atts.item(i);
                    String nodeName = att.getNodeName();
                    if ((nodeName.equals("xmlns") || nodeName.startsWith("xmlns:"))
                        && !storedNamespaces.containsKey(att.getNodeName())) {
                        sb.append(" " + nodeName + "=\"" + att.getNodeValue() + "\"");
                        storedNamespaces.put(nodeName, att.getNodeValue());
                    }
                }
            }
            wk = wk.getParentNode();
        }
        sb.append(">" + source + "</dummy>");
        return sb.toString();
    }

}