在Java中加载C带符号的长整型

#include <stdio.h>

long long loadSignedLong() {
    // 加载C带符号的长整型的逻辑
    // ...
    long long result = 1234567890LL;  // 示例，假设加载结果为1234567890
    return result;
}

public class CLongLoader {
    static {
        System.loadLibrary("clongloader");  // 加载C动态链接库
    }
    
    public native long loadSignedLong();  // 声明native方法
    
    public static void main(String[] args) {
        CLongLoader loader = new CLongLoader();
        long result = loader.loadSignedLong();  // 调用C函数
        System.out.println("Loaded signed long: " + result);
    }
}

javac CLongLoader.java  // 编译Java类
javah -jni CLongLoader  // 生成C头文件

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class CLongLoader */

#ifndef _Included_CLongLoader
#define _Included_CLongLoader
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     CLongLoader
 * Method:    loadSignedLong
 * Signature: ()J
 */
JNIEXPORT jlong JNICALL Java_CLongLoader_loadSignedLong
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

#include "CLongLoader.h"

JNIEXPORT jlong JNICALL Java_CLongLoader_loadSignedLong(JNIEnv *env, jobject obj) {
    // 加载C带符号的长整型的逻辑
    // ...
    jlong result = 1234567890LL;  // 示例，假设加载结果为1234567890
    return result;
}

gcc -shared -o libclongloader.so -I"$JAVA_HOME/include" -I"$JAVA_HOME/include/linux" CLongLoader.c

java CLongLoader

Loaded signed long: 1234567890