第一步生成静态库.a文件：

cmake 语法如何生成静态库，就不介绍了，比较简单，我下文列出的参考资料里面有详细介绍。

add_library(${CMAKE_PROJECT_NAME} STATICsrc/CalculStatic.cpp)

这一步有坑，我刚开始的时候，也花了不少时间，死活都没有生成.a静态库文件。但是我多方查找资料，发现是可以生成静态库文件的。关键是要配置“targets” 。这个属性只有在“ defaultConfig” 下面才能配置出来，在大括号“android ”下面配置的“cmake ”是没有“targets”这个属性的，我就是因为在此耽搁了不少时间。一定要谨慎。

参考资料：https://stackoverflow.com/questions/64829357/specify-targets-in-externalnativebuild-of-the-build-gradle-file-no-signature-o

正确的build.gradle配置如下：

android {defaultConfig {:externalNativeBuild {cmake {targets "calStatic" // New line here!}}}externalNativeBuild {cmake {path "src/main/cpp/CMakeLists.txt"version "3.10.2"// targets "native-lib"  // Not here!}}
}

重新运行项目或者“Make Project”. 重新刷新目录，静态库.a文件就可以正确生成了。

参考资料：
android studio生成静态库没有*.a目标文件问题
android studio 3.2 使用cmake在jni生成及使用C/C++静态库

第二步使用静态库.a文件：

限制我们需要来调用我们刚刚生成的静态库.a文件

CMakeLists.txt

cmake_minimum_required(VERSION 3.22.1)project("cmake")add_library(${CMAKE_PROJECT_NAME} SHAREDnative-lib.cppsrc/libtest.c)#导入已经编译好的静态库 或者 动态库  本例导入的静态库
add_library(calStatic STATIC IMPORTED)
#设置静态库导入的路径
set_target_properties(calStatic PROPERTIES IMPORTED_LOCATION${CMAKE_CURRENT_SOURCE_DIR}/jni/${CMAKE_ANDROID_ARCH_ABI}/libcalStatic.a
)#通过target_link_libraries命令指明库文件，且通过target_include_directories命令指明相应的库头文件
target_include_directories(${CMAKE_PROJECT_NAME} PUBLIC ${PROJECT_SOURCE_DIR}/include/static/)
#需要链接或者编译的库
target_link_libraries(${CMAKE_PROJECT_NAME}# List libraries link to the target libraryandroidcalStaticlog)

native-lib.cpp

#include "CalculStatic.h"//调用了libcalStatic.a静态库中的方法jint addSum(JNIEnv *env,jobject instance,jint a,jint b,jint c){ //调用静态库return  calculAdd(a,b,c);//动态注册
jint RegisterNatives(JNIEnv *env) {jclass clazz = env->FindClass("com/gitbaike/cmake/MainActivity");if (clazz == NULL) {LOGE("con't find class: com/gitbaike/cmake/MainActivity");return JNI_ERR;}JNINativeMethod methods_MainActivity[] = {{"stringFromJNI", "()Ljava/lang/String;", (void *) stringFromJNI},{"add",           "(II)I",                (void *) add},{"changePersonName", "(Lcom/gitbaike/cmake/model/Person;)V",(void *) changeName},{"getPerson", "()Lcom/gitbaike/cmake/model/Person;",(void *)getNewPerson},{"getPeronList", "()Ljava/util/List;",(void *) getListPerson},{"addSum", "(III)I",(void *)addSum}};// int len = sizeof(methods_MainActivity) / sizeof(methods_MainActivity[0]);return env->RegisterNatives(clazz, methods_MainActivity,sizeof(methods_MainActivity) / sizeof(methods_MainActivity[0]));
}jint JNI_OnLoad(JavaVM *vm, void *reserved) {JNIEnv *env = NULL;if (vm->GetEnv((void **) &env, JNI_VERSION_1_6) != JNI_OK) {return JNI_ERR;}jint result = RegisterNatives(env);LOGD("RegisterNatives result: %d", result);return JNI_VERSION_1_6;
}

Java端调用：

public class MainActivity extends AppCompatActivity {private static final String TAG = "MainActivity";// Used to load the 'cmake' library on application startup.static {System.loadLibrary("cmake");}private ActivityMainBinding binding;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);binding = ActivityMainBinding.inflate(getLayoutInflater());setContentView(binding.getRoot());//         Example of a call to a native methodTextView tv = binding.sampleText;tv.setText(stringFromJNI());HNPCInit();Person person=new Person();person.setAge(12);person.setName("java person");Log.d(TAG,"调用本地方法前： person.getName:"+person.getName());changePersonName(person);Log.d(TAG,"调用本地方法后： person.getName:"+person.getName());Person nPerson=getPerson();Log.d(TAG,"调用本地方法 getPerson()后： person:"+nPerson.toString());List<Person> personList=getPeronList();Log.d(TAG,"调用本地方法 getPerson()后： personList:"+new Gson().toJson(personList) );Log.d(TAG,"调用本地方法 addSum:"+addSum(10,15,65));}/*** A native method that is implemented by the 'cmake' native library,* which is packaged with this application.*/public native String stringFromJNI();public native void HNPCInit();public native int add(int a,int b);public  native void changePersonName(Person mPerson);public native Person getPerson();public native List<Person> getPeronList();private native int addSum(int a,int b,int c);
}

运行结果：