我用Ubuntu 10.10
我就是这么做的.
Hello.java:
class Hello {
public native void sayHello();
static { System.loadLibrary("hellolib"); }
public static void main(String[] args){
Hello h = new Hello();
h.sayHello();
}
}
然后我运行以下命令:
dierre@cox:~/Scrivania/provajni$ javac Hello.java
dierre@cox:~/Scrivania/provajni$ javah -jni Hello
我得了Hello.class
分和Hello.h
分.
Hello.h:
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class Hello */
#ifndef _Included_Hello
#define _Included_Hello
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: Hello
* Method: sayHello
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_Hello_sayHello
(JNIEnv *, jobject);
#ifdef __cplusplus
}
#endif
#endif
然后我创造了Hello.cpp:
#include <jni.h>
#include "Hello.h"
#include <iostream>
using namespace std;
JNIEXPORT void JNICALL Java_Hello_sayHello (JNIEnv *env, jobject obj) {
cout << "Hello World!" << endl;
return;
}
现在我觉得我搞砸了.我当时inspired岁
dierre@cox:~/Scrivania/provajni$ gcc -I"/usr/lib/jvm/java-6-sun/include" -I"/usr/lib/jvm/java-6-sun/include/linux" -o hellolib.so -shared -Wl,-soname,hello.so Hello.cpp -static -lc
这将生成文件hellolib.so
但当我try 用java Hello
运行它时,我有一个错误:
Exception in thread "main" java.lang.UnsatisfiedLinkError: no hellolib in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1734)
at java.lang.Runtime.loadLibrary0(Runtime.java:823)
at java.lang.System.loadLibrary(System.java:1028)
at Hello.<clinit>(Hello.java:4)
Could not find the main class: Hello. Program will exit.
我甚至试过:
LD_LIBRARY_PATH=`pwd`
export LD_LIBRARY_PATH
没有结果.
我知道我在做一件非常愚蠢的事,但我不知道那是什么.动态库是用-shared选项生成的,不是吗?
Update #1
我试了static { System.load("/home/dierre/Scrivania/provajni/hellolib.so"); }
次,看看这是否有效,但现在:
Exception in thread "main" java.lang.UnsatisfiedLinkError: /home/dierre/Scrivania/provajni/hello.so: /home/dierre/Scrivania/provajni/hello.so: undefined symbol: _ZSt4cout
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1803)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1699)
at java.lang.Runtime.load0(Runtime.java:770)
at java.lang.System.load(System.java:1003)
at Hello.<clinit>(Hello.java:4)
Update #2