java-tutorials/jni/src/main/cpp/com_baeldung_jni_ExampleObjectsJNI.cpp
Miguel Rivero 62b5a591af BAEL-1637: Guide to JNI(Java Native Interface) (#4066)
* BAEL-1546: Java 8 Math additions

* Applied feedback to Unit Tests

* BAEL-1546 Added missing test annotations

* Added code for BAEL-1637

* Added script for Windows C++ code compile

* Added compilation script for MacOS

* Added some Unit tests
2018-05-15 22:18:41 +01:00

49 lines
1.7 KiB
C++

#include "com_baeldung_jni_ExampleObjectsJNI.h"
#include <iostream>
/*
* Class: com_baeldung_jni_ExampleObjectsJNI
* Method: createUser
* Signature: (Ljava/lang/String;D)Lcom/baeldung/jni/UserData;
*/
JNIEXPORT jobject JNICALL Java_com_baeldung_jni_ExampleObjectsJNI_createUser
(JNIEnv *env, jobject thisObject, jstring name, jdouble balance){
// Create the object of the class UserData
jclass userDataClass = env->FindClass("com/baeldung/jni/UserData");
jobject newUserData = env->AllocObject(userDataClass);
// Get UserData fields to set
jfieldID nameField = env->GetFieldID(userDataClass , "name", "Ljava/lang/String;");
jfieldID balanceField = env->GetFieldID(userDataClass , "balance", "D");
// Set the values of the new object
env->SetObjectField(newUserData, nameField, name);
env->SetDoubleField(newUserData, balanceField, balance);
// Return the created object
return newUserData;
}
/*
* Class: com_baeldung_jni_ExampleObjectsJNI
* Method: printUserData
* Signature: (Lcom/baeldung/jni/UserData;)Ljava/lang/String;
*/
JNIEXPORT jstring JNICALL Java_com_baeldung_jni_ExampleObjectsJNI_printUserData
(JNIEnv *env, jobject thisObject, jobject userData){
// Find the class method id
jclass userDataClass = env->GetObjectClass(userData);
jmethodID methodId = env->GetMethodID(userDataClass, "getUserInfo", "()Ljava/lang/String;");
// Call the object method and get the result
jstring result = (jstring)env->CallObjectMethod(userData, methodId);
// Print the result
std::cout << "C++: User data is: " << env->GetStringUTFChars(result, NULL) << std::endl;
return result;
}