好的,所以我有下面的本机代码.
我试图从它返回一个FilePermissionInfo数组,填充stat()返回的一些数据.
问题是第一次调用NewObject时出现以下错误：
我试图从它返回一个FilePermissionInfo数组,填充stat()返回的一些数据.
问题是第一次调用NewObject时出现以下错误：
06-15 20:25:17.621: W/dalvikvm(2287): Invalid indirect reference
0x40005820 in decodeIndirectRef 06-15 20:25:17.621: E/dalvikvm(2287):
VM aborting
这很奇怪,因为我唯一的参考对象是jclass(对于FilePermissionInfo),我把它变成了一个全局引用.
代码是：
JNIEXPORT jobjectArray JNICALL
Java_com_mn_rootscape_utils_NativeMethods_getFilesPermissions( JNIEnv* env,jobject thizz,jobjectArray filePathsArray )
{
jobjectArray result;
int size = (*env)->GetArrayLength(env,filePathsArray);
jboolean isCopy;
jclass filePermInfoCls = (*env)->FindClass(env,kFilePermissionInfoPath);
if(!filePermInfoCls)
{
LOGE("getFilesPermissions: Failed to get class reference.");
return NULL;
}
gFilePermInfoClass = (jclass)(*env)->NewGlobalRef(env,filePermInfoCls);
LOGI("got gFilePermInfoClass");
jmethodID filePermInfoClsConstructor = (*env)->GetMethodID(env,gFilePermInfoClass,"<init>",kFilePermInfoConstructorSig);
if(!filePermInfoClsConstructor)
{
LOGE("getFilesPermissions: Failed to get method reference.");
return NULL;
}
struct stat sb;
LOGI("starting...");
result = (jobjectArray)(*env)->NewObjectArray(env,size,NULL);
for(int i = 0; i != size; ++i)
{
jstring string = (jstring) (*env)->GetObjectArrayElement(env,filePathsArray,i);
const char *rawString = (*env)->GetStringUTFChars(env,string,&isCopy);
if(stat(rawString,&sb) == -1)
{
LOGE("stat error for: %s",rawString);
}
LOGI("%ld %ld %ld %ld %ld %ld %ld %ld",sb.st_dev,sb.st_mode,sb.st_nlink,sb.st_uid,sb.st_gid,sb.st_atime,sb.st_mtime,sb.st_ctime);
jobject permInfo = (*env)->NewObject(env,filePermInfoClsConstructor,(long)sb.st_dev,(long)sb.st_mode,(long)sb.st_nlink,(long)sb.st_uid,(long)sb.st_gid,(long)sb.st_atime,(long)sb.st_mtime,(long)sb.st_ctime,"",1,"");
LOGI("xxx1");
(*env)->SetObjectArrayElement(env,result,i,permInfo);
LOGI("xxx2");
(*env)->ReleaseStringUTFChars(env,rawString);
LOGI("xxx3");
}
(*env)->DeleteLocalRef(env,filePermInfoCls);
return result;
}
Java类构造函数签名和路径是：
const char* kFilePermissionInfoPath = "com/mn/rootscape/utils/FilePermissionInfo"; const char* kFilePermInfoConstructorSig = "(JJJJJJJJLjava/lang/String;Ljava/lang/String;ZLjava/lang/String;)V";
解决方法
好的,找到了.
这是jstring参数的问题.事实证明,你不能将空字符串(或者甚至是NULL)作为jstring传递.
相反,我使用(* env) – > NewStringUTF(env,NULL)来创建NULL jstring.
这是jstring参数的问题.事实证明,你不能将空字符串(或者甚至是NULL)作为jstring传递.
相反,我使用(* env) – > NewStringUTF(env,NULL)来创建NULL jstring.
好像现在好了.
由于这个问题产生了一定程度的高活动,我将在下面发布最终解决方案.请注意,nullString变量在其作用域的末尾(或者当您使用它时)被释放：
jstring nullString = (*env)->NewStringUTF(env,NULL);
...
jobject permInfo = (*env)->NewObject(env,(jbyte)permsOwner,(jbyte)permsGroup,(jbyte)permsOthers,(jlong)sb.st_uid,(jlong)sb.st_gid,(jlong)sb.st_atime,(jlong)sb.st_mtime,(jlong)sb.st_ctime,nullString,(jboolean)1,nullString);
...
(*env)->DeleteLocalRef(env,nullString);
