Java 如何使jstring脱离jobject?c++;
我正在尝试从jobject中获取字符串属性。我找不到任何解决问题的方法,谷歌也没有帮助 这是我的Java类:Java 如何使jstring脱离jobject?c++;,java,c++,dll,java-native-interface,Java,C++,Dll,Java Native Interface,我正在尝试从jobject中获取字符串属性。我找不到任何解决问题的方法,谷歌也没有帮助 这是我的Java类: public class HumanBean { String name; int alter; int gehalt; double gehaltDouble; ....getter and setter... } CPP文件-注释代码是我试图从jobject中提取名称字符串的地方 Human createHuman(JNIEnv *env
public class HumanBean {
String name;
int alter;
int gehalt;
double gehaltDouble;
....getter and setter...
}
CPP文件-注释代码是我试图从jobject中提取名称字符串的地方
Human createHuman(JNIEnv *env, jclass cls, jobject javaObject) {
jclass cls = (*env).GetObjectClass(javaObject);
//jfieldID fidInt = (*env).GetFieldID(cls, "name", "Ljava/lang/String;");
//jstring name = ??????????????????????
jfieldID fidInt = (*env).GetFieldID(cls, "alter", "I");
jint alter = (*env).GetIntField(objarg, fidInt);
jfieldID fidInt = (*env).GetFieldID(cls, "gehalt", "I");
jint gehaltInt = (*env).GetIntField(objarg, fidInt);
jfieldID fidInt = (*env).GetFieldID(cls, "gehaltDouble", "D");
jdouble gehaltDouble = (*env).GetDoubleField(objarg, fidInt);
Human newHuman = Human(alter, name, gehaltDouble, gehaltInt);
return newHuman;
}
我认为这会奏效:
jfieldID fidName = (*env).GetFieldID(cls, "name", "Ljava/lang/String;");
jstring nameString = (jstring)(*env).GetObjectField(cls, fidName);
不相关,但请注意,
(*foo).method(…)
最好写成foo->method(…)
这里的关键点是jstring
继承自jobject
。这种向下转换是安全的(毕竟,您正在检索一个字符串
),但编译器无法知道这一点。