code in blog.sheimi.me: hello JNI

HelloJNI-modified.java

//Here is HelloJNI.java
public class HelloJNI {

  static {
    try {
      Class c = HelloJNI.class;
      URL location =
        c.getProtectionDomain().getCodeSource().getLocation();
      ZipFile zf = new ZipFile(location.getPath());
      // libhellojni.so is put in the lib folder
      InputStream in = zf.getinputStream(zf.getEntry("lib/libhellojni.so"));
      File f = File.createTempFile("JNI-", "Temp");
      FileOutputStream out = new FileOutputStream(f);
      byte [] buf = new byte[1024];
      int len;
      while ((len = in.read(buf)) > 0)
        out.write(buf, 0, len);
      in.close();
      out.close();
      System.load(f.getAbsolutePath());
      f.delete();
    } catch (Exception e) { // I am still lazy ~~~
      e.printStackTrace();
    }
  }

  public static native String showMessage(String msg);

  public static void main(String [] args) {
    String msg = HelloJNI.showMessage("Hello JNI");
    System.out.println("Here is in Java");
    System.out.println(msg);
  }
}

hellojni.c

//Here is hellojni.c
#include "stdio.h"
#include "hellojni.h"

JNIEXPORT jstring JNICALL
Java_HelloJNI_showMessage(JNIEnv * env, 
                          jclass classObject,
                          jstring valueObject)
{
  fprintf(stdout, "Here is C output\n");
  return valueObject;
}

HelloJNI.java

//Here is HelloJNI.java
public class HelloJNI {
  static {
    try {
      System.loadLibrary("hellojni");
    } catch (Exception e) {     // I am a little indolent
      e.printStackTrace();
    }
  }

  public static native String showMessage(String msg);

  public static void main(String [] args) {
    String msg = HelloJNI.showMessage("Hello JNI");
    System.out.println("Here is in Java");
    System.out.println(msg);
  }
}