Create JNI C method : JNI « Development Class « Java
Create JNI C method
/**
@version 1.10 1997-07-01
@author Cay Horstmann
*/
#include "Printf1.h"
#include <stdio.h>
JNIEXPORT jint JNICALL Java_Printf1_print(JNIEnv* env, jclass cl,
jint width, jint precision, jdouble x)
{
char fmt[30];
jint ret;
sprintf(fmt, "%%%d.%df", width, precision);
ret = printf(fmt, x);
fflush(stdout);
return ret;
}
///////////////////////////////////////
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @version 1.10 1997-07-01
* @author Cay Horstmann
*/
class Printf1
{
public static native int print(int width, int precision, double x);
static
{
System.loadLibrary("Printf1");
}
}
///////////////////////////////////////
/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @version 1.10 1997-07-01
* @author Cay Horstmann
*/
class Printf1Test
{
public static void main(String[] args)
{
int count = Printf1.print(8, 4, 3.14);
count += Printf1.print(8, 4, count);
System.out.println();
for (int i = 0; i < count; i++)
System.out.print("-");
System.out.println();
}
}
Printf1Test.zip( 1 k)