与JNI的UnsatisfiedLinkError

Question

.h文件

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

JNIEXPORT void JNICALL Java_NativePackage_HelloWorld_displayHelloWorld(JNIEnv *env, jobject obj)   {
printf("Hello world!\n");
return;
}

爪哇

package NativePackage;

public class HelloWorld {
public native void displayHelloWorld();

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

public static void main(String[] args) {
    new HelloWorld().displayHelloWorld();
}
}

.c文件

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

JNIEXPORT void JNICALL Java_NativePackage_HelloWorld_displayHelloWorld(JNIEnv *env, jobject obj){
printf("Hello world!\n");
return;
}

我使用

编译了我的.c文件

gcc -I /Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home/include/ -I  /Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home/include/darwin/ -fPIC -o hello -c   HelloWorldImp.c 

但是，尝试使用java NativePackage/HelloWorld运行会产生以下错误：

java  -Djava.library.path=NativePackage/ NativePackage/HelloWorld

Exception in thread "main" java.lang.UnsatisfiedLinkError: no hello in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1857)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1119)
at NativePackage.HelloWorld.<clinit>(HelloWorld.java:7)

我正在运行MAC OS X 10.10

Answer 1

尝试使用

System.load("/home/project/lib/libhello.so");

给出库的绝对路径。

当我遇到同样的问题时帮助了我。

Answer 2

似乎可以使用OS X libhello.dylib 和 -shared 选项的正确命名方案。

gcc -I /Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home/include/ -I /Library/Java/JavaVirtualMachines/jdk1.8.0_20.jdk/Contents/Home/include/darwin/  -o libhello.dylib -shared HelloWorldImp.c