file1.c

学习JAVA编程的示例

#include <jni.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

JNIEXPORT jbyteArray JNICALL Java_ReadFile_loadFile
        (JNIEnv *env, jobject jobj, jstring name) {
        caddr_t m;
        jbyteArray jb;
        jboolean iscopy;
        struct stat finfo;
        const char *mfile = (*env)->GetStringUTFChars(env, name, &iscopy);
        int fd = open(mfile, O_RDONLY);
        if (fd == -1) {
                printf("Could not open %s\n", mfile);
        }
        lstat(mfile, &finfo);
        m = mmap((caddr_t)0, finfo.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        if (m == (caddr_t)-1) {
                printf("Could not mmap %s\n",mfile);
                return(0);
        }
        jb = (*env)->NewByteArray(env, finfo.st_size);
        (*env)->SetByteArrayRegion(env, jb, 0, finfo.st_size, (jbyte *)m);
        close(fd);
        (*env)->ReleaseStringUTFChars(env, name, mfile);
        return(jb);
        }