xmpschema.java

iText是一个能够快速产生PDF文件的java类库。iText的java类对于那些要产生包含文本

/*
 * $Id: XmpSchema.java 2749 2007-05-15 12:09:43Z blowagie $
 * $Name$
 *
 * Copyright 2005 by Bruno Lowagie.
 *
 * The contents of this file are subject to the Mozilla Public License Version 1.1
 * (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the License.
 *
 * The Original Code is 'iText, a free JAVA-PDF library'.
 *
 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
 * the Initial Developer are Copyright (C) 1999-2005 by Bruno Lowagie.
 * All Rights Reserved.
 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
 * are Copyright (C) 2000-2005 by Paulo Soares. All Rights Reserved.
 *
 * Contributor(s): all the names of the contributors are added in the source code
 * where applicable.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
 * provisions of LGPL are applicable instead of those above.  If you wish to
 * allow use of your version of this file only under the terms of the LGPL
 * License and not to allow others to use your version of this file under
 * the MPL, indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by the LGPL.
 * If you do not delete the provisions above, a recipient may use your version
 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE 
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the MPL as stated above or under the terms of the GNU
 * Library General Public License as published by the Free Software Foundation;
 * either version 2 of the License, or any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU LIBRARY GENERAL PUBLIC LICENSE for more
 * details.
 *
 * If you didn't download this code from the following link, you should check if
 * you aren't using an obsolete version:
 * http://www.lowagie.com/iText/
 */

package com.lowagie.text.xml.xmp;

import java.util.Enumeration;
import java.util.Properties;

/**
 * Abstract superclass of the XmpSchemas supported by iText.
 */
public abstract class XmpSchema extends Properties {
	
	/** the namesspace */
	protected String xmlns;
	
	/** Constructs an XMP schema. 
	 * @param xmlns
	 */
	public XmpSchema(String xmlns) {
		super();
		this.xmlns = xmlns;
	}
	/**
	 * The String representation of the contents.
	 * @return a String representation.
	 */
	public String toString() {
		StringBuffer buf = new StringBuffer();
		for (Enumeration e = this.propertyNames(); e.hasMoreElements(); ) {
			process(buf, e.nextElement());
		}
		return buf.toString();
	}
	/**
	 * Processes a property
	 * @param buf
	 * @param p
	 */
	protected void process(StringBuffer buf, Object p) {
		buf.append('<');
		buf.append(p);
		buf.append('>');
		buf.append(this.get(p));
		buf.append("</");
		buf.append(p);
		buf.append('>');
	}
	/**
	 * @return Returns the xmlns.
	 */
	public String getXmlns() {
		return xmlns;
	}	
	
	/**
	 * @param key
	 * @param value
	 * @return the previous property (null if there wasn't one)
	 */
	public synchronized Object addProperty(String key, String value) {
		return this.setProperty(key, value);
	}
	
	/**
	 * @see java.util.Properties#setProperty(java.lang.String, java.lang.String)
	 */
	public synchronized Object setProperty(String key, String value) {
		return super.setProperty(key, escape(value));
	}
	
	/**
	 * @see java.util.Properties#setProperty(java.lang.String, java.lang.String)
	 * 
	 * @param key
	 * @param value
	 * @return the previous property (null if there wasn't one)
	 */
	public synchronized Object setProperty(String key, XmpArray value) {
		return super.setProperty(key, value.toString());
	}
	
	/**
	 * @see java.util.Properties#setProperty(java.lang.String, java.lang.String)
	 * 
	 * @param key
	 * @param value
	 * @return the previous property (null if there wasn't one)
	 */
	public synchronized Object setProperty(String key, LangAlt value) {
		return super.setProperty(key, value.toString());
	 }
	
	/**
	 * @param content
	 * @return an escaped string
	 */
	public static String escape(String content) {
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < content.length(); i++) {
			switch(content.charAt(i)) {
			case '<':
				buf.append("&lt;");
				break;
			case '>':
				buf.append("&gt;");
				break;
			case '\'':
				buf.append("&apos;");
				break;
			case '\"':
				buf.append("&quot;");
				break;
			case '&':
				buf.append("&amp;");
				break;
			default:
				buf.append(content.charAt(i));
			}
		}
		return buf.toString();
	}
}