{"id":4820,"date":"2023-06-27T20:59:25","date_gmt":"2023-06-27T12:59:25","guid":{"rendered":"https:\/\/blog.coderfan.org\/?p=4820"},"modified":"2023-06-27T20:59:32","modified_gmt":"2023-06-27T12:59:32","slug":"android-jni-usagge","status":"publish","type":"post","link":"https:\/\/blog.coderfan.org\/en\/android-jni-usagge.html","title":{"rendered":"Android JNI\u4f7f\u7528"},"content":{"rendered":"
\n
\n \t<\/i> Read Time:<\/span>2 Minute, 21 Second <\/div>\n\n <\/div>\n

\u7ecf\u5e38\u505aAndroid\u5f00\u53d1\u7684\u670b\u53cb\u4e0d\u53ef\u907f\u514d\u5730\u4f1a\u63a5\u89e6\u5230\u4e00\u4e2a\u8bcd\uff1aJNI\uff0c\u5176\u82f1\u6587\u5168\u79f0\u4e3aJava-Native Interface\uff0cJNI\u7684\u4f5c\u7528\u5373\u5728\u4e8e\u901a\u8fc7JNI\u53ef\u4ee5\u8ba9\u6211\u4eec\u4eceJava\u4ee3\u7801\u8c03\u7528\u5230C++\u4ee3\u7801\u3002<\/p>\n\n\n\n

\u4e00\u822c\u6211\u4eec\u5728\u5f00\u53d1APP\u65f6\uff0c\u7531\u4e8eFramework\u5c42\u6ca1\u6709\u5bf9\u5e94\u7684\u6846\u67b6\u5b9e\u73b0\uff0c\u53ef\u80fd\u9700\u8981\u8c03\u7528C\/C++\u7f16\u5199\u7684\u4ee3\u7801\uff0c\u6216\u8005\u662f\u51fa\u4e8e\u5b89\u5168\u9700\u8981\u5c06\u6838\u5fc3\u4ee3\u7801\u4f7f\u7528C\/C++\u7f16\u5199\uff0c\u8fdb\u800c\u901a\u8fc7JNI\u6765\u8c03\u7528\u3002<\/p>\n\n\n\n

\u4f7f\u7528JNI\u9700\u8981\u63d0\u524d\u914d\u7f6eNDK\uff0c\u56e0\u4e3aC++\u4ee3\u7801\u4f9d\u8d56\u4e8eNDK\u73af\u5883\u3002\u5728AndroidStudio\u4e2d\u914d\u7f6eNDK\u65f6\u9996\u5148\u9700\u8981\u901a\u8fc7File->Settings->System Settings->Android SDK->SDK Tools\u5185\u9009\u62e9NDK\u8fdb\u884c\u4e0b\u8f7d\uff0c\u5e76\u901a\u8fc7File->Project Structure->Android NDK location\u914d\u7f6e\u5176\u8def\u5f84\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

AndroidStudio\u4e2d\u914d\u7f6e\u4f7f\u7528JNI\u5927\u81f4\u53ef\u9075\u5faa\u5982\u4e0b\u6b65\u9aa4\uff1a<\/p>\n\n\n\n

1.\u5728app\/src\/main\u76ee\u5f55\u4e0b\u521b\u5efacpp\u76ee\u5f55\uff0c\u5e76\u6dfb\u52a0CMakeLists.txt,\u5176\u5185\u5bb9\u5927\u81f4\u5982\u4e0b\uff1a<\/p>\n\n\n\n

# For more information about using CMake with Android Studio, read the\n# documentation: https:\/\/d.android.com\/studio\/projects\/add-native-code.html\n \n# Sets the minimum version of CMake required to build the native library.\n# \u8bbe\u7f6ecmake \u7684\u6700\u5c0f\u7248\u672c  \u4e00\u822c\u7cfb\u7edf\u81ea\u52a8\u751f\u6210\ncmake_minimum_required(VERSION 3.4.1)\n \n# Creates and names a library, sets it as either STATIC\n# or SHARED, and provides the relative paths to its source code.\n# You can define multiple libraries, and CMake builds them for you.\n# Gradle automatically packages shared libraries with your APK.\n#\u8bbe\u5b9a\u76ee\u6807\u4ea7\u7269\u7c7b\u578b\u3001\u540d\u79f0\u3001\u6e90\u7801\u7b49\u4fe1\u606f\nadd_library( # Sets the name of the library.\n             # \u8bbe\u7f6e\u751f\u6210.so \u7684\u6587\u4ef6\u540d\uff0c\u6700\u7ec8\u4ea7\u7269\u4e3alibnative-lib.so\n             native-lib\n             # Sets the library as a shared library.\n             #\u8bbe\u7f6e\u5e93\u7684\u7c7b\u578b  \u4e00\u79cd\u9759\u6001\u6587\u4ef6  STATIC .a   \u4e00\u79cd\u52a8\u6001\u6587\u4ef6  SHARED .so\n             SHARED\n             # Provides a relative path to your source file(s).\n             # \u9700\u8981\u7f16\u8bd1\u7684c\/c++ \u6587\u4ef6\uff0c\u4ee5CMakeLists.txt\u6240\u5728\u76ee\u5f55\u4e3a\u57fa\u51c6\u7684\u76f8\u5bf9\u76ee\u5f55\n             src\/main\/cpp\/main.cpp )\n\n# Searches for a specified prebuilt library and stores the path as a\n# variable. Because CMake includes system libraries in the search path by\n# default, you only need to specify the name of the public NDK library\n# you want to add. CMake verifies that the library exists before\n# completing its build.\n# \u4f9d\u8d56\u7684NDK\u7b2c\u4e09\u65b9\u5e93--\nfind_library( # Sets the name of the path variable.\n              dependencies-lib\n              # Specifies the name of the NDK library that\n              # you want CMake to locate.\n              EGL, #\u4f9d\u8d56libEGL.so\n              nativehelper #\u4f9d\u8d56libnativehelper.so\n              log )#\u4f9d\u8d56liblog.so\n \n# Specifies libraries CMake should link to your target library. You\n# can link multiple libraries, such as libraries you define in this\n# build script, prebuilt third-party libraries, or system libraries.\n \ntarget_link_libraries( # Specifies the target library.\n                       # \u6307\u5b9a\u94fe\u63a5\u7684\u76ee\u6807\u5e93\n                       native-lib\n \n                       # Links the target library to the log library\n                       # included in the NDK.\n                       ${dependencies-lib } )<\/code><\/pre>\n\n\n\n
\u5173\u4e8eCMake\u7684\u66f4\u591a\u4f7f\u7528\u4fe1\u606f\uff0c\u53ef\u4ee5\u53c2\u8003\u6211\u7684\u8fd9\u7bc7\u535a\u5ba2<\/a>\u3002<\/p>\n\n\n\n
2.\u5728app\/build.gradle\u4e2d\u5c06gradle\u4e0ecmake\u8fdb\u884c\u5173\u8054\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n\n\n\n
android {\n   defaultConfig {\n\texternalNativeBuild{\n      cmake{\n\t  cflags \u201c_D\u201d\n\t  cppflags \u201c-frtti\u201d,\u201d-fexceptions\u201d\n\t  abiFilters \u2018x86\u2019,\u2019x86_64\u2019,\u2019armabi\u2019,\u2019armeabi-v7a\u2019,\u2019arm64-v8a\u2019\n      }\n   }\n    .......\n    externalNativeBuild {\n        cmake {\n\t    \/\/\u901a\u8fc7path\u5173\u952e\u5b57\u6307\u5b9aCMakeLists.txt\u8def\u5f84\n\t    \/\/\u8be5\u8def\u5f84\u662f\u662f\u4ee5build.gradle\u4e3a\u57fa\u51c6\u7684\u76f8\u5bf9\u8def\u5f84\n            path \"CMakeLists.txt\"\n        }\n    }\n}<\/code><\/pre>\n\n\n\n
3.\u6dfb\u52a0\u5173\u952e\u4ee3\u7801\uff0c\u5173\u952e\u4ee3\u7801\u7684\u6dfb\u52a0\u5206\u4e3a\u4e24\u90e8\u5206\uff0c\u4e00\u90e8\u5206\u662fC\/C++\u4ee3\u7801\uff0c\u53e6\u5916\u4e00\u90e8\u5206\u662fJava\u4ee3\u7801\u3002<\/p>\n\n\n\n
\u9996\u5148\u662fJava\u4ee3\u7801,\u5305\u62ec\u52a0\u8f7dJNI\u5e93\uff0c\u540c\u65f6\u58f0\u660enative \u51fd\u6570\u3002\u5982\u4e0b\u793a\u4f8b\uff1a<\/p>\n\n\n\n
\/\/here we will load jni library\nstatic {\n     System.loadLibrary(\"natiave-lib\"); \/\/\u8be5\u540d\u79f0\u5bf9\u5e94cmake\u4e2d\u7684add_library\u6240\u6dfb\u52a0\u7684\u5e93\u540d\n}\n\/\/ Native method declaration\nprivate native boolean nUpdateTexture(HardwareBuffer buffer, int textureId);<\/code><\/pre>\n\n\n\n
\u7136\u540e\u6211\u4eec\u9700\u8981\u7f16\u5199C\/C++\u4ee3\u7801\uff1a<\/p>\n\n\n\n
\/\/\u5fc5\u987b\u8981\u5f15\u7528jni.h\u5934\u6587\u4ef6\n#include <jni.h>\n\n\/\/\u6b64\u5916\u6709\u4e24\u4e2a\u91cd\u8981\u7684\u51fd\u6570JNI_OnLoad\u3001JNI_OnUnload\u662f\u9700\u8981\u53bb\u5b8c\u6210\u7684\n\/\/\u5f53native library\u88ab\u52a0\u8f7d\u65f6\uff08\u5982\u8c03\u7528System.loadLibrary\uff09,JAVA VM\u5c06\u4f1a\u8c03\u7528JNI_Onload,\u8fd4\u56deJNI\u7248\u672c\nJNIEXPORT jint JNI_OnLoad(JavaVM* vm, void* \/*reserved*\/) {\n\n}\n\n\/\/\u5f53JAVA\u7c7b\u52a0\u8f7d\u5668\u53d1\u751fGC\u65f6\uff0c\u8be5\u51fd\u6570\u5c06\u4f1a\u88abJAVA VM\u8fdb\u884c\u8c03\u7528\u3002\u901a\u5e38\u8be5\u51fd\u6570\u5c06\u7528\u4e8e\u6e05\u7406\u5de5\u4f5c\u3002\nJNIEXPORT void JNI_OnUnload(JavaVM* vm, void* \/*reserved*\/) {\n\n}<\/code><\/pre>\n\n\n\n
\u6b64\u5916\u6211\u4eec\u8fd8\u9700\u8981\u4e86\u89e3\u4e00\u4e0bJNI\u4e2d\u7684\u6570\u636e\u7c7b\u578b\uff0c\u4ee5\u4fbf\u5c06Java\u4e2d\u7684\u6570\u636e\u7c7b\u578b\u4e0enative\u539f\u751f\u7c7b\u578b\u505a\u5339\u914d:<\/p>\n\n\n\n
<\/a>Java Type<\/th><\/a>Native Type<\/th><\/a>Description<\/th><\/tr><\/thead>
<\/a>boolean<\/td><\/a>jboolean<\/td><\/a>unsigned 8 bits<\/td><\/tr>
<\/a>byte<\/td><\/a>jbyte<\/td><\/a>signed 8 bits<\/td><\/tr>
<\/a>char<\/td><\/a>jchar<\/td><\/a>unsigned 16 bits<\/td><\/tr>
<\/a>short<\/td><\/a>jshort<\/td><\/a>signed 16 bits<\/td><\/tr>
<\/a>int<\/td><\/a>jint<\/td><\/a>signed 32 bits<\/td><\/tr>
<\/a>long<\/td><\/a>jlong<\/td><\/a>signed 64 bits<\/td><\/tr>
<\/a>float<\/td><\/a>jfloat<\/td><\/a>32 bits<\/td><\/tr>
<\/a>double<\/td><\/a>jdouble<\/td><\/a>64 bits<\/td><\/tr>
<\/a>void<\/td><\/a>void<\/td><\/a>N\/A<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u9664\u4e86\u539f\u751f\u6570\u636e\u7c7b\u578b\uff0cJNI\u4e2d\u4e5f\u5b58\u5728\u4e0eJava\u4e2d\u5bf9\u5e94\u7684\u590d\u5408\u7c7b\u578b\uff0c\u5176\u5bf9\u5e94\u5173\u7cfb\u5982\u4e0b\uff1a<\/p>\n\n\n\n
Java Type <\/td>Native Type <\/td><\/tr>
java.lang.Class<\/td>jclass<\/td><\/tr>
java.lang.String<\/td>jstring<\/td><\/tr>
arrays<\/td>jarray<\/td><\/tr>
java.lang.Throwable<\/td>jthrowable<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u5728\u7f16\u5199\u5b8c\u76f8\u5173\u4ee3\u7801\u540e\uff0c\u5728Androud Studio\u4e2d\u4f60\u53ef\u4ee5\u5728Build\u7a97\u53e3\u4e2d\u67e5\u770b\u7f16\u8bd1\u76f8\u5173\u7684\u62a5\u9519\u4fe1\u606f\uff1b\u5982\u679c\u4f60\u9700\u8981\u66f4\u51c6\u786e\u5730\u83b7\u53d6C\/C++\u76f8\u5173\u7684\u8bca\u65ad\u4fe1\u606f\uff0c\u53ef\u4ee5\u5728app\/.cxx\u76ee\u5f55\u4e0b\u627e\u5230\u66f4\u591a\u7684\u6709\u6548\u4fe1\u606f\uff0c\u5982CMakeCache.txt\u7b49\u3002<\/p>\n        
\n            
\n                \n                
\n                    \n                        \"Happy\"\n                    <\/a>\n                    
\n                        Happy                    <\/div>\n                    
\n                                                    1<\/span>\n                        \n                                                100<\/span> %<\/span>\n                                            <\/div>\n                <\/div>\n\n                
\n                    \n                        \"Sad\"\n                    <\/a>\n                    
\n                        Sad                    <\/div>\n                    
\n                                                    0<\/span>\n                                                                        0<\/span> %<\/span>\n                                            <\/div>\n                <\/div>\n\n                
\n                    \n                        \"Excited\"\n                    <\/a>\n                    
\n                        Excited                    <\/div>\n                    
\n                                                    0<\/span>\n                                                                        0<\/span> %<\/span>\n                                            <\/div>\n                <\/div>\n\n                
\n                    \n                        \"Sleepy\"\n                    <\/a>\n                    
\n                        Sleepy                    <\/div>\n                    
\n                                                    0<\/span>\n                        \n                                                0<\/span> %<\/span>\n                                            <\/div>\n                <\/div>\n\n                
\n                    \n                        \"Angry\"\n                    <\/a>\n                    
Angry<\/div>\n                    
\n                                                    0<\/span>\n                                                                        0<\/span> %<\/span>\n                        \n                    <\/div>\n                <\/div>\n\n                
\n                    \n                        \"Surprise\"\n                    <\/a>\n                    
Surprise<\/div>\n                    
\n                                                    0<\/span>\n                                                                        0<\/span> %<\/span>\n                                            <\/div>\n                <\/div>\n\n            <\/div>\n        <\/div>","protected":false},"excerpt":{"rendered":"
Android JNI\u4f7f\u7528\u76f8\u5173\u8bb0\u5f55<\/p>","protected":false},"author":1,"featured_media":4483,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_editorskit_title_hidden":false,"_editorskit_reading_time":2,"_editorskit_is_block_options_detached":false,"_editorskit_block_options_position":"{}","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[18],"tags":[46],"class_list":["post-4820","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-operating-system","tag-android"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[]}},"aioseo_notices":[],"featured_image_urls":{"full":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"thumbnail":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-150x150.jpg",150,150,true],"medium":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-300x158.jpg",300,158,true],"medium_large":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"large":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"1536x1536":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"2048x2048":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"trp-custom-language-flag":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-18x9.jpg",18,9,true]},"post_excerpt_stackable":"
Android JNI\u4f7f\u7528\u76f8\u5173\u8bb0\u5f55<\/p>\n","category_list":"\u64cd\u4f5c\u7cfb\u7edf<\/a>","author_info":{"name":"FranzKafka95","url":"https:\/\/blog.coderfan.org\/en\/author\/yushenglonely95"},"comments_num":"0 comments","featured_image_urls_v2":{"full":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"thumbnail":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-150x150.jpg",150,150,true],"medium":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-300x158.jpg",300,158,true],"medium_large":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"large":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"1536x1536":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"2048x2048":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android.jpg",512,269,false],"trp-custom-language-flag":["https:\/\/blog.coderfan.org\/wp-content\/uploads\/2023\/04\/android-18x9.jpg",18,9,true]},"post_excerpt_stackable_v2":"
Android JNI\u4f7f\u7528\u76f8\u5173\u8bb0\u5f55<\/p>\n","category_list_v2":"\u64cd\u4f5c\u7cfb\u7edf<\/a>","author_info_v2":{"name":"FranzKafka95","url":"https:\/\/blog.coderfan.org\/en\/author\/yushenglonely95"},"comments_num_v2":"0 comments","_links":{"self":[{"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/posts\/4820","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/comments?post=4820"}],"version-history":[{"count":8,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/posts\/4820\/revisions"}],"predecessor-version":[{"id":4831,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/posts\/4820\/revisions\/4831"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/media\/4483"}],"wp:attachment":[{"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/media?parent=4820"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/categories?post=4820"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.coderfan.org\/en\/wp-json\/wp\/v2\/tags?post=4820"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}