ubuntu移植jsoncpp到Android平台(转）

NDK开发模块的时候，如果涉及到网络请求，类似json数据传递的时候，有现成的第三方json库可以移植，后台C++开发中使用的比较多的是jsoncpp，今天记录一下jsoncpp移植到Android平台的过程

cmake编译

此方法并非标准的NDK项目
采用的是cmake交叉编译生成
jsoncpp地址
https://github.com/open-source-parsers/jsoncpp
先将源码克隆下来
新建文件夹libjson
将jsoncpp源码中的include文件夹复制到该目录，然后进入src/lib_json目录复制
部分文件到libjson目录下的src目录中，如下

作者：Andy周
链接：https://www.jianshu.com/p/02ccd73c927e
來源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

json_reader.cpp
json_tool.h
json_value.cpp
json_valueiterator.inl
json_writer.cpp
version.h.in

在libjson目录新建文件CMakeLists.txt
内容如下

 CMAKE_MINIMUM_REQUIRED(VERSION 3.5)
 PROJECT(Jpp)

 SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")

 #ARCHS集合
 SET(ARCHS "arm" "arm64" "x86" "x86_64" "mips" "mips64")

 #PLATFORM集合
 SET(PLATFORM "arm-linux-androideabi" "aarch64-linux-android" "i686-linux-android" "x86_64-linux-android" "mipsel-linux-android" "mips64el-linux-android")

 SET(JSONCPP_INCLUDE_DIR include)

 INCLUDE_DIRECTORIES(${JSONCPP_INCLUDE_DIR})

 SET(PUBLIC_HEADERS
     ${JSONCPP_INCLUDE_DIR}/json/config.h
     ${JSONCPP_INCLUDE_DIR}/json/forwards.h
     ${JSONCPP_INCLUDE_DIR}/json/features.h
     ${JSONCPP_INCLUDE_DIR}/json/value.h
     ${JSONCPP_INCLUDE_DIR}/json/reader.h
     ${JSONCPP_INCLUDE_DIR}/json/writer.h
     ${JSONCPP_INCLUDE_DIR}/json/assertions.h
     ${JSONCPP_INCLUDE_DIR}/json/version.h
     )

 SOURCE_GROUP("Public API" FILES ${PUBLIC_HEADERS})

 SET(jsoncpp_sources
                 src/json_tool.h
                 src/json_reader.cpp
                 src/json_valueiterator.inl
                 src/json_value.cpp
                 src/json_writer.cpp
                 src/version.h.in)

 #INDEX= "arm"
 #INDEX= "arm64"
 #INDEX= "x86"
 #INDEX= "x86_64"
 #INDEX= "mips"
 #INDEX= "mips64"

 SET(INDEX )

 list(GET ARCHS ${INDEX} TARGET_ARCH)
 list(GET PLATFORM ${INDEX} TARGET_PLATFORM)

 MESSAGE("ARCH= " ${TARGET_ARCH})
 MESSAGE("PLATFORM= " ${TARGET_PLATFORM})

 SET(CMAKE_C_COMPILER "$ENV{HOME}/android-toolchain/${TARGET_ARCH}/bin/${TARGET_PLATFORM}-gcc")
 SET(CMAKE_CXX_COMPILER "$ENV{HOME}/android-toolchain/${TARGET_ARCH}/bin/${TARGET_PLATFORM}-g++")

 SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 SET(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)

 ADD_LIBRARY(${TARGET_ARCH}_share SHARED ${PUBLIC_HEADERS} ${jsoncpp_sources})
 SET_TARGET_PROPERTIES(${TARGET_ARCH}_share PROPERTIES OUTPUT_NAME ${TARGET_ARCH})
 ADD_LIBRARY(${TARGET_ARCH}_static STATIC ${PUBLIC_HEADERS} ${jsoncpp_sources})
 SET_TARGET_PROPERTIES(${TARGET_ARCH}_static PROPERTIES OUTPUT_NAME ${TARGET_ARCH})

编译之前确认已安装cmake
如果没有，请先安装

sudo apt-get install cmake

目录结构如下

 

交叉编译请，参考笔者之前记录的《NDK交叉编译之自定义工具链》

准备工作做好之后可以进行编译了

cmake .
make

笔者目前只编译了arm平台的，如果有需要其他平台的，只需要改动上述CMakeLists.txt中的编号即可

SET(INDEX )

NDK原生编译

测试

下面简单测试一下，就不建Android项目了
新建文件夹JNI
将刚才生成的libarm.a和include文件夹放入进去，新建文件Android.mk

 LOCAL_PATH := $(call my-dir)

 include $(CLEAR_VARS)

 LOCAL_MODULE    := jsoncpp
 LOCAL_SRC_FILES := libarm.a
 include $(PREBUILT_STATIC_LIBRARY)  

 include $(CLEAR_VARS)
 LOCAL_MODULE    := main
 LOCAL_C_INCLUDES  := $(LOCAL_PATH)/include/json
 LOCAL_SRC_FILES := main.cpp
 LOCAL_CPPFLAGS := -fexceptions

 LOCAL_STATIC_LIBRARIES := jsoncpp  

 LOCAL_CFLAGS += -pie -fPIE
 LOCAL_LDFLAGS += -pie -fPIE

 LOCAL_LDLIBS := -llog

 include $(BUILD_EXECUTABLE)

新建Application.mk文件

 APP_ABI := armeabi
 APP_PLATFORM :=
 APP_STL := gnustl_static
 APP_CPPFLAGS := -fexceptions -frtti
 APP_CPPFLAGS += -std=gnu++
 APP_CPPFLAGS += -fpermissive

新建main.cpp

 #include <jni.h>
 #include <iostream>
 #include "include/json/json.h"

 using namespace std;

 void JsonTest();

 int main(){
     JsonTest();
     return ;
 }

 void JsonTest(){
     Json::Value root;
     Json::Value array;
     Json::Value item;

     for (int i = ; i < ; i ++)
     {
         item["id"] = i;
         item["name"] = "name";
         array.append(item);
     }

     root["username"] = "andy";
     root["age"] = ;
     root["array"] = array;

     string out = root.toStyledString();
     cout << out << endl;
 }

然后编译

ndk-build

然后将生成的main执行文件上传到手机中测试，手机需要root权限
笔者一般丢在/data/local目录下测试

./main

转自：https://www.jianshu.com/p/02ccd73c927e