de.intarsys.pdf.cos.COSName Maven / Gradle / Ivy

Go to download
/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * - Neither the name of intarsys nor the names of its contributors may be used
 *   to endorse or promote products derived from this software without specific
 *   prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package de.intarsys.pdf.cos;

import java.io.UnsupportedEncodingException;
import java.util.Arrays;

/**
 * A name object.
 */
public class COSName extends COSPrimitiveObject {

	static public COSName constant(String name) {
		return (COSName) COSName.create(name).beConstant();
	}

	static public COSName constantUTF8(String name) {
		return (COSName) COSName.createUTF8(name).beConstant();
	}

	static public COSName create(byte[] bytes) {
		return new COSName(bytes, true);
	}

	static public COSName create(String name) {
		return new COSName(name.getBytes(), true);
	}

	static public COSName createUTF8(String name) {
		try {
			return new COSName(name.getBytes("UTF-8"), true); //$NON-NLS-1$
		} catch (UnsupportedEncodingException e) {
			// ...?
			return new COSName(name.getBytes(), true);
		}
	}

	/** if string representation is needed it is lazy computed on base of UTF 8 */
	private String string;

	/** the underlying byte representation */
	private final byte[] bytes;

	/** cached hash value */
	private int hash;

	/**
	 * COSName constructor.
	 * 
	 * @param newName
	 *            The name value for the object.
	 */
	protected COSName(byte[] newName) {
		super();
		bytes = newName;
	}

	/**
	 * COSName constructor. Dummy constructor to include hash computation
	 * 
	 * @param newName
	 *            The name value for the object.
	 */
	protected COSName(byte[] newName, boolean computeHash) {
		super();
		bytes = newName;
		computeHash();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.cos.COSObject#accept(de.intarsys.pdf.cos.ICOSObjectVisitor)
	 */
	@Override
	public java.lang.Object accept(ICOSObjectVisitor visitor)
			throws COSVisitorException {
		return visitor.visitFromName(this);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.cos.COSObject#asName()
	 */
	@Override
	public COSName asName() {
		return this;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.cos.COSObject#basicToString()
	 */
	@Override
	protected String basicToString() {
		return "/" + stringValue(); //$NON-NLS-1$
	}

	/**
	 * The bytes that make up this name (without "/")
	 * 
	 * @return The bytes that make up this name (without "/")
	 */
	public byte[] byteValue() {
		return bytes;
	}

	private void computeHash() {
		int h = 0;
		for (int i = 0; i < bytes.length; i++) {
			h = (31 * h) + bytes[i];
		}
		hash = h;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.cos.COSObject#copyBasic(de.intarsys.pdf.cos.COSDocument)
	 */
	@Override
	protected COSObject copyBasic() {
		COSName result = new COSName(bytes);
		result.string = this.string;
		result.hash = this.hash;
		return result;
	}

	protected String decode() {
		/*
		 * UTF-8 Test: a UTF-8 encoded character starts with 110xxxxx or
		 * 1110xxxx or 11110xxx followed by 1 to 3 bytes in form: 10xxxxxx. This
		 * algorithm looks for the UTF-8 start and 1 followup character. If one
		 * sequence is found, UTF-8 is assumed, otherwise not. F8: 1111 1000 F0:
		 * 1111 0000 E0: 1110 0000 C0: 1100 0000 08: 1000 0000
		 */
		boolean utf8 = false;
		for (int i = 0; i < bytes.length; i++) {
			if (bytes[i] < 0) {
				int test = bytes[i] & 0x00F8;
				if ((test == 0x00C0) || (test == 0x00E0) || (test == 0x00F0)) {
					if ((i + 1) == bytes.length) {
						break;
					}
					i++;
					if ((bytes[i] & 0x00C0) == 0x0080) {
						utf8 = true;
					}
					break;
				}
			}
		}

		if (utf8) {
			try {
				return new String(bytes, "UTF-8"); //$NON-NLS-1$
			} catch (UnsupportedEncodingException e) {
				return new String(bytes);
			}
		} else {
			return new String(bytes);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object o) {
		if (this == o) {
			return true;
		}
		if (!(o instanceof COSName)) {
			return false;
		}
		return Arrays.equals(bytes, ((COSName) o).byteValue());
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		return hash;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.pdf.cos.COSObject#restoreState(java.lang.Object)
	 */
	@Override
	public void restoreState(Object object) {
		super.restoreState(object);
		COSName name = (COSName) object;
		this.string = name.string;
		this.hash = name.hash;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.tools.objectsession.ISaveStateSupport#saveState()
	 */
	public Object saveState() {
		COSName result = new COSName(bytes);
		result.string = this.string;
		result.hash = this.hash;
		result.container = this.container.saveStateContainer();
		return result;
	}

	/**
	 * The string value that makes up this name (without "/")
	 * 
	 * @return The string value that makes up this name (without "/")
	 */
	@Override
	public java.lang.String stringValue() {
		if (string == null) {
			string = decode();
		}
		return string;
	}
}