com.sun.jna.NativeString Maven / Gradle / Ivy

/* This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) 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
 * Lesser General Public License for more details.  
 */
package com.sun.jna;


/** Provides a temporary allocation of an immutable C string 
 * (const char* or const wchar_t*) for use when 
 * converting a Java String into a native memory function argument.  
 *
 * @author  Todd Fast, [email protected]
 * @author [email protected]
 */
class NativeString implements CharSequence, Comparable {

    private String value;
    private Pointer pointer;

    /** Create a native string (NUL-terminated array of char).

     * If the system property jna.encoding is set, its value will
     * be used to encode the native string.  If not set or if the encoding
     * is unavailable, the default platform encoding will be used. 
     */
    public NativeString(String string) {
        this(string, false);
    }

    /** Create a native string as a NUL-terminated array of wchar_t
     * (if wide is true) or char.
     * If the system property jna.encoding is set, its value will
     * be used to encode the native charstring.  
     * If not set or if the encoding is unavailable, the default platform 
     * encoding will be used. 
     * 
     * @param string value to write to native memory
     * @param wide whether to store the String as wchar_t
     */
    public NativeString(String string, boolean wide) {
        this.value = string;
        if (string == null) {
            throw new NullPointerException("String must not be null");
        }
        // Allocate the memory to hold the string.  Note, we have to
        // make this 1 element longer in order to accommodate the terminating 
        // NUL (which is generated in Pointer.setString()).
        if (wide) {
            int len = (string.length() + 1 ) * Native.WCHAR_SIZE;
            pointer = new Memory(len);
            pointer.setString(0, string, true);
        }
        else {
            byte[] data = Native.getBytes(string);
            pointer = new Memory(data.length + 1);
            pointer.setString(0, string);
        }
    }

    public int hashCode() {
        return value.hashCode();
    }

    public boolean equals(Object other) {

        if (other instanceof CharSequence) {
            return compareTo(other) == 0;
        }
        return false;
    }

    public String toString() {
        return value;
    }

    public Pointer getPointer() {
        return pointer;
    }

    public char charAt(int index) {
        return value.charAt(index);
    }

    public int length() {
        return value.length();
    }

    public CharSequence subSequence(int start, int end) {
        return value.subSequence(start, end);
    }

    public int compareTo(Object other) {

        if (other == null)
            return 1;

        return value.compareTo(other.toString());
    }
}