java - C:以编程方式查找 JVM 库文件位置

Question

是否有独立于平台的方法来使用 C 查找 JVM 库(Linux 上的 libjvm.so 和 Windows 上的 jvm.dll)的位置？

我试过使用 libltdl API这确实适用于某些(可能很多)平台，但不适用于 Ubuntu。

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <ftw.h>
#include <string.h>

static char* jvm_lib_fpath;

static int check_file(const char *fpath, const struct stat *sb, int typeflag) {
    static const char LINUX_LIB[] = "libjvm.so";
    static const char WINDOWS_LIB[] = "jvm.dll";
    const char *libs[] = {LINUX_LIB, WINDOWS_LIB};
    int i;

    for (i = 0; i < 2; i++) {
        const char* lib = libs[i];
        const size_t m = strlen(lib); 

        const size_t n = strlen(fpath) - m; 

        const char* test = &fpath[n]; 

        if (strcmp(test, lib) == 0) {
            const size_t fpath_len = strlen(fpath) + 1;
            jvm_lib_fpath = (char*) malloc(fpath_len * sizeof(char));
            if (jvm_lib_fpath == NULL) return -1;
            strcpy(jvm_lib_fpath, fpath);

            return 1;
        }
    }

    return 0;
}

static int set_jvm_lib_fpath() {
    char* java_home = getenv("JAVA_HOME");

    int result = ftw(java_home, check_file, 128);

    return result;
}

int main() {
    int result = set_jvm_lib_fpath();
    if (result == 1) {
        printf("jvm_lib_fpath: '%s'\n", jvm_lib_fpath);
    } else {
        printf("Could not find JVM library file.\n");
    }
    if (jvm_lib_fpath) {
        free(jvm_lib_fpath);
    }

    return 0;
}