JNI - “无法打开包含文件:'jni_md.h'"； [英] JNI - "Cannot open include file: 'jni_md.h'"

问题描述

此示例程序旨在调用用 C 编写的 native 方法.

This sample program is meant to call a native method written in C.

Java 代码

class HelloWorld {

    private native void print();

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

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

}

写完之后我编译了程序并生成了一个JNI风格的头文件.

After writing this i compiled the program and generated a JNI style header file.

生成的头文件是:

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <C:Program FilesJavajdk1.7.0includejni.h>
/* Header for class HelloWorld */

#ifndef _Included_HelloWorld
#define _Included_HelloWorld
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     HelloWorld
 * Method:    print
 * Signature: ()V
 */
 JNIEXPORT void JNICALL Java_HelloWorld_print
 (JNIEnv *, jobject);

 #ifdef __cplusplus
 }
 #endif
 #endif

以及用c编写的本机方法

#include <C:Program FilesJavajdk1.7.0includejni.h>
#include <C:Program FilesJavajdk1.7.0includewin32jni_md.h>
#include <stdio.h>
#include "HelloWorld.h"

JNIEXPORT void JNICALL Java_HelloWorld_print( JNIENv *env , jobject obj) {
    printf("Hello World!
");
    return;
}

我在编译时遇到的错误是 fatal error C1083: Cannot open include file: 'jni_md.h': No such file or directory

The error I get on compiling is fatal error C1083: Cannot open include file: 'jni_md.h': No such file or directory

我的编译器也在 jobject obj 下划线，说 这个类没有存储类或说明符.它在 *env 下划线，表示 expected a ')'.

Also my compiler underlines jobject obj saying that this class does not have storage class or specifier . It underlines *env saying expected a ')'.

为什么会出现这个错误?

Why do I get this error ?

推荐答案

我怀疑 jni.h 正在尝试 #include ，其中然后失败，因为您没有将其位置添加到您的包含路径中.

I suspect that jni.h is trying to #include <jni_md.h>, which is then failing because you haven't added its location to your include path.

尝试将这两个条目添加到 C 编译器的包含路径中:

Try adding both of these entries to your C compiler's include path:

• C:Program FilesJavajdk1.7.0include
• C:Program FilesJavajdk1.7.0includewin32

win32 路径可能不是必需的，具体取决于 jni.h 的设置方式.

The win32 path might not be necessary, depending on how jni.h is set up.

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