com.sun.jna.NativeString Maven / Gradle / Ivy
/*
* The contents of this file is dual-licensed under 2
* alternative Open Source/Free licenses: LGPL 2.1 or later and
* Apache License 2.0. (starting with JNA version 4.0.0).
*
* You can freely decide which license you want to apply to
* the project.
*
* You may obtain a copy of the LGPL License at:
*
* http://www.gnu.org/licenses/licenses.html
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "LGPL2.1".
*
* You may obtain a copy of the Apache License at:
*
* http://www.apache.org/licenses/
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "AL2.0".
*/
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 {
static final String WIDE_STRING = "--WIDE-STRING--";
private Pointer pointer;
private String encoding;
private class StringMemory extends Memory {
public StringMemory(long size) { super(size); }
@Override
public String toString() {
return NativeString.this.toString();
}
}
/** Create a native string (NUL-terminated array of char).
* Uses the encoding returned by {@link Native#getDefaultStringEncoding()}.
*/
public NativeString(String string) {
this(string, Native.getDefaultStringEncoding());
}
/** Create a native string as a NUL-terminated array of wchar_t
* (if wide is true) or char.
* If not wide, the encoding is obtained from {@link
* Native#getDefaultStringEncoding()}.
*
* @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(string, wide ? WIDE_STRING : Native.getDefaultStringEncoding());
}
/** Create a native string as a NUL-terminated array of
* wchar_t.
*/
public NativeString(WString string) {
this(string.toString(), WIDE_STRING);
}
/** Create a native string (NUL-terminated array of char),
* using the requested encoding.
*/
public NativeString(String string, String encoding) {
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()).
this.encoding = encoding;
if (WIDE_STRING.equals(this.encoding)) {
int len = (string.length() + 1 ) * Native.WCHAR_SIZE;
pointer = new StringMemory(len);
pointer.setWideString(0, string);
} else {
byte[] data = Native.getBytes(string, encoding);
pointer = new StringMemory(data.length + 1);
pointer.write(0, data, 0, data.length);
pointer.setByte(data.length, (byte)0);
}
}
@Override
public int hashCode() {
return toString().hashCode();
}
@Override
public boolean equals(Object other) {
if (other instanceof CharSequence) {
return compareTo(other) == 0;
}
return false;
}
@Override
public String toString() {
boolean wide = WIDE_STRING.equals(encoding);
return (wide ? pointer.getWideString(0) : pointer.getString(0, encoding));
}
public Pointer getPointer() {
return pointer;
}
@Override
public char charAt(int index) {
return toString().charAt(index);
}
@Override
public int length() {
return toString().length();
}
@Override
public CharSequence subSequence(int start, int end) {
return toString().subSequence(start, end);
}
@Override
public int compareTo(Object other) {
if (other == null)
return 1;
return toString().compareTo(other.toString());
}
}