利用jni如何在C中将String数组转化为char**

java代码如下：
Java code:


public class TestJni {

private static native void print(School s);

public static void main(){

School s = new School();
print(s);
}


}

class School{

String[] studentNames = {"tom","jack","sophia"};

}




在C代码中，如何把这个s.studentNames转化成为char**呢？
我写了一个ReadStringArray()的函数，但是是有问题的，在原有字符串后面会加几个乱码。
C/C++ code:

char** ReadStringArray(JNIEnv * env, jclass jc, jobject jo, char* name, int size){
jfieldID id_array = env->GetFieldID(jc,name,"[Ljava/lang/String;");
jobjectArray joa_array = (jobjectArray)env->GetObjectField(jo,id_array);
char** stringArray = new char*[size];

for(int i = 0; i < size; i++){

jobject obj_string = env->GetObjectArrayElement(joa_array,i);
jclass class_string = env->GetObjectClass(obj_string);
jfieldID id_value = env->GetFieldID(class_string,"value","[C");
jcharArray jca_value = (jcharArray)env->GetObjectField(obj_string,id_value);
int jca_size = env->GetArrayLength(jca_value);