CppCallJni

Author: durongze

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.4.1)
+# close openssl
+
+project(CppCallJni)
+
+add_subdirectory(callc)
+
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DDYZ_DBG")
+set(JAVA_HOME "$ENV{JAVA_HOME}")
+file(GLOB C_LIBRARY_SRC callc/*.cpp callc/*.h)
+file(GLOB CPP_CALL_JNI_SRC *.cpp *.h)
+MESSAGE(STATUS "JAVA_HOME DIR: ${JAVA_HOME} ENV_JAVA_HOME DIR: $ENV{HOME}")
+
+include_directories(CppCallJni ${CMAKE_CURRENT_SOURCE_DIR}/ ${CMAKE_CURRENT_SOURCE_DIR}/callc ${JAVA_HOME}/include/ ${JAVA_HOME}/include/win32)
+link_directories(CppCallJni ${CMAKE_CURRENT_SOURCE_DIR}/callc ${JAVA_HOME}/lib/)
+add_executable(CppCallJni ${C_LIBRARY_SRC} ${CPP_CALL_JNI_SRC})
+target_link_libraries(CppCallJni jvm)

CppCallJni.cpp

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+#include "com_durongze_jni_CallC.h"
+#include <Windows.h>
+
+#define JAVA_HOME "D:\\Program Files\\Java\\jre1.8.0_60"
+
+#define JVM_DLL JAVA_HOME "\\bin\\server\\" "jvm.dll"
+typedef int (*JNICreateJavaVM)(JavaVM **pvm, void **penv, void *args);
+int main() {
+	JavaVM *pvm = NULL;
+	JNIEnv *penv = NULL;
+	JavaVMInitArgs args;
+	JavaVMOption options[1] = {"-Djava.class.path=.;D:\\Program Files\\Java\\jre1.8.0_60\\lib\\dt.jar;D:\\Program Files\\Java\\jre1.8.0_60\\lib\\tools.jar"};
+	args.options = options;
+	args.nOptions = 1;
+	args.version = JNI_VERSION_1_6;
+	args.ignoreUnrecognized = JNI_TRUE;
+	char *jvmDll = JVM_DLL;
+	HMODULE hmod = LoadLibraryA("D:\\Program Files\\Java\\jre1.8.0_60\\bin\\server\\jvm.dll");
+	JNICreateJavaVM pJNICreateJavaVM = (JNICreateJavaVM)GetProcAddress(hmod, "JNI_CreateJavaVM");
+	int status = pJNICreateJavaVM(&pvm, (void**)&penv, (void**)&args);
+	if (status == JNI_ERR) {
+		return 0;
+	}
+	int num = 2;
+	jclass intArrCls = penv->FindClass("java/lang/String");
+	jobjectArray names = penv->NewObjectArray(num, intArrCls, NULL);
+	jintArray ages = penv->NewIntArray(num);
+	jfloatArray heights = penv->NewFloatArray(num);
+
+	for (int idx = 0; idx < num; ++idx) {
+		const char *pns = "xxx"; 
+		jstring ns = penv->NewStringUTF(pns);
+		jint intArr[1] = { idx };
+		jfloat floatArr[1] = { idx };
+		penv->SetIntArrayRegion(ages, idx, 1, intArr);
+		penv->SetFloatArrayRegion(heights, idx, 1, floatArr);
+		penv->SetObjectArrayElement(names, idx, ns);
+		penv->ReleaseStringUTFChars(ns, 0);
+	}
+
+	jobjectArray res = (jobjectArray)Java_com_durongze_jni_CallC_CInterface(penv, NULL, names, ages, heights, num);
+
+	pvm->DestroyJavaVM();
+}

build.bat

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+set JAVA_HOME=D:\Program Files\Java\jdk1.8.0_60
+set PATH=%PATH%;%JAVA_HOME%\bin;E:\Android\sdk\ndk-bundle\android-ndk-r20
+
+rem ndk-build NDK_PROJECT_PATH=. NDK_APPLICATION_MK=Application.mk APP_BUILD_SCRIPT=Android.mk
+
+mkdir dyzbuild
+pushd dyzbuild
+cmake -G "Visual Studio 14 2015 Win64" ..
+call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\vcvars32.bat"
+msbuild CppCallJni.vcxproj
+popd