fiftyone.mobile.detection.entities.AsciiString Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of 51Degrees.detection.core Show documentation
51Degrees core detection solution
The newest version!
package fiftyone.mobile.detection.entities;

import fiftyone.mobile.detection.Dataset;
import fiftyone.mobile.detection.readers.BinaryReader;

/* *********************************************************************
 * This Source Code Form is copyright of 51Degrees Mobile Experts Limited. 
 * Copyright 2014 51Degrees Mobile Experts Limited, 5 Charlotte Close,
 * Caversham, Reading, Berkshire, United Kingdom RG4 7BY
 * 
 * This Source Code Form is the subject of the following patent 
 * applications, owned by 51Degrees Mobile Experts Limited of 5 Charlotte
 * Close, Caversham, Reading, Berkshire, United Kingdom RG4 7BY: 
 * European Patent Application No. 13192291.6; and 
 * United States Patent Application Nos. 14/085,223 and 14/085,301.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.
 * 
 * If a copy of the MPL was not distributed with this file, You can obtain
 * one at http://mozilla.org/MPL/2.0/.
 * 
 * This Source Code Form is "Incompatible With Secondary Licenses", as
 * defined by the Mozilla Public License, v. 2.0.
 * ********************************************************************* */
/**
 * ASCII format strings are the only ones used in the data set. Many native
 * string formats use Unicode format using 2 bytes for every character. This is
 * inefficient when only ASCII values are being stored. The AsciiString class
 * wraps a byte array of ASCII characters and exposes them as a native string
 * type when required.  Strings stored as ASCII strings include, the relevant
 * characters from signatures, sub strings longer than 4 characters, property
 * and value names, the descriptions and URLs associated with properties and
 * values.  For more information see
 * http://51degrees.mobi/Support/Documentation/Java
 */
public class AsciiString extends BaseEntity {

    /**
     * The value of the string in ASCII bytes.
     */
    final byte[] value;

    /**
     * The length of the byte array or string in characters.
     * @return length of the byte array or string in characters.
     */
    public int getLength() {
        return value.length;
    }

    /**
     * Constructs a new instance of AsciiString
     *
     * @param dataSet The data set whose strings list the string is contained
     * within
     * @param offset The offset to the start of the string within the string
     * data structure
     * @param reader reader to be used
     */
    public AsciiString(Dataset dataSet, int offset, BinaryReader reader) {
        super(dataSet, offset);

        // The length includes the null byte which we're not interested in.
        this.value = reader.readBytes(reader.readInt16() - 1);

        // Read the null byte to ensure the file position is at the 
        // expected place for the next string.
        reader.readByte();
    }

    /**
     * .NET string representation of the ASCII string.
     *
     * @return ASCII string as a native string.
     */
    @Override
    public String toString() {
        if (stringValue == null) {
            synchronized (this) {
                if (stringValue == null) {
                    stringValue = new String(value);
                }
            }
        }
        return stringValue;
    }
    private String stringValue = null;
}