线程“main”java.lang中的异常。如果3

Hi guys i have tried all the solutions like java -Djava.library.path=. demo adding the dll path to PATH java -Djava.library.path=c:\JNI\demo.dll demo

我已经尝试了所有的解决方案，如java -Djava.library.path=。演示添加dll路径到path java -Djava.library.path=c:\JNI\demo。dll演示

But still the above error.

但仍然是上面的错误。

Here is my java code..

这是我的java代码。

class demo
{
    public native void printline();
    public static void main(String[]args)
    {
        new demo().printline();
    }
}

Here is my c code...

这是我的c代码…

#include<stdio.h>
#include<jni.h>

#include "demo.h"

JNIEXPORT void JNICALL Java_demo_printline(JNIEnv *a, jobject b)
{
    printf("Hello wrold!!!");
    return;
}

Steps for compiling and running,

编译和运行的步骤，

javac demo.java
javac demo.java
javah demo
javah演示
gcc -c -I"c:\jdk1.7.0_55\include" -I"c:\jdk1.7.0_55\include\win32" demo.c
c -I -c:\jdk1.7.0_55\包括" -I"c:\jdk1.7.0_55\包括\win32" demo.c。
gcc -Wl,--add-stdcall-alias -shared -o demo.dll demo.c
gcc -Wl，- add-stdcall-alias -shared -o演示。dll demo.c
java -Djava.library.path=c:\JNI\demo.dll demo
java -Djava.library.path = c:\ JNI \ demo。dll演示

Am i going wrong somewhere?

我哪里出错了吗?

can someone please help me out,.

有人能帮我吗?

2 个解决方案

#1

Try Run-Time Loading of the dll file within the java code in a static block like:

在静态块中，尝试在java代码中运行dll文件的运行时加载:

static
{
System.loadLibrary("demo");
}

should give you the output.

应该给你输出。

Moreover make sure that dll file generated is x32 or x64 according to the gcc compiler in use.

此外，根据使用的gcc编译器，确保生成的dll文件是x32或x64。

#2

looking for "JNI hello world" (or many other terms, possibly), would have given you the answer.

寻找“JNI hello world”(或者其他许多术语，可能)，会给你答案。

for example:

例如:

http://www3.ntu.edu.sg/home/ehchua/programming/java/JavaNativeInterface.html

you need to load the library inside your java code
您需要在java代码中加载该库。
you need to specify the path to the directory of the library, not to the library itsself, in java.library.path
您需要为库的目录指定路径，而不是在java.library.path中指定库本身。

#1