基本思想:本来项目需求,需要写Android代码,开发组件模块,因为极其讨厌java;顾转而使用Android studio 提供了c++的功能,开发功能模块;之前的代码使用了boost库,所以需要使用boost源码静态编译成静态包,然后导入Android studio工程使用;
以PC机为例子写了本教程;
1、下载源代码
axel -n 100 https://dl.bintray.com/boostorg/release/1.73.0/source/boost_1_73_0.tar.bz2
tar -jxvf boost_1_73_0.tar.bz2
cd boost_1_73_0/
mkdir liboost
./bootstrap.sh
./b2 -a cxxflags='-fPIC -std=c++11' install --prefix=/home/ubuntu/boost_1_73_0/liboost link=static threading=multi
然后在liboost文件夹产生了对应的头文件include和lib静态包
ubuntu@ubuntu:~/boost_1_73_0/liboost$ tree -L 2
.
├── include
│ └── boost
└── lib
├── cmake
├── libboost_atomic.a
├── libboost_chrono.a
├── libboost_container.a
├── libboost_context.a
├── libboost_contract.a
├── libboost_coroutine.a
├── libboost_date_time.a
├── libboost_exception.a
├── libboost_fiber.a
├── libboost_filesystem.a
├── libboost_graph.a
├── libboost_iostreams.a
├── libboost_locale.a
├── libboost_log.a
├── libboost_log_setup.a
├── libboost_math_c99.a
├── libboost_math_c99f.a
├── libboost_math_c99l.a
├── libboost_math_tr1.a
├── libboost_math_tr1f.a
├── libboost_math_tr1l.a
├── libboost_nowide.a
├── libboost_prg_exec_monitor.a
├── libboost_program_options.a
├── libboost_python27.a
├── libboost_random.a
├── libboost_regex.a
├── libboost_serialization.a
├── libboost_stacktrace_addr2line.a
├── libboost_stacktrace_backtrace.a
├── libboost_stacktrace_basic.a
├── libboost_stacktrace_noop.a
├── libboost_system.a
├── libboost_test_exec_monitor.a
├── libboost_thread.a
├── libboost_timer.a
├── libboost_type_erasure.a
├── libboost_unit_test_framework.a
├── libboost_wave.a
└── libboost_wserialization.a
4 directories, 40 files
然后就原则上可以把这个liboost文件夹导入Android Studio 的工程中使用静态库了;
测试代码:
#include <boost/date_time/gregorian/gregorian.hpp>
#include <iostream>
using namespace std;
int main()
{
boost::gregorian::date d(boost::gregorian::day_clock::local_day());
cout << d.year()<<"." << d.month()<<"." <<d.day() <<endl;
return 0;
}
编译与执行:
ubuntu@ubuntu:~/test$ g++ -I liboost/include/ liboost/lib/libboost_timer.a testliboost.cpp
ubuntu@ubuntu:~/test$ ./a.out
2020.Aug.4
ubuntu@ubuntu:~/test$ g++ -I liboost/include/ -I liboost/lib/ testliboost.cpp
ubuntu@ubuntu:~/test$ ./a.out
2020.Aug.4
如果使用CMakeList.txt进行编译的;需要将生成的文件夹拷贝到工程中然后修改对应的CMakeList.txt文件,文件结构和修改点如下:
然后即可以使用pc端编译的liboost库;
移植Android 端使用交叉编译的liboost库:
需要使用交叉编译器去编译liboost的的源码,我为了方便并未使用交叉编译器去编译https://blog.csdn.net/sxj731533730/article/details/106115331,;{ 进入目录执行./bootstrap.sh;
此时形成bjam文件和project-config.jam 编辑project-config.jam, 仅修改using gcc这行。因为我使用的是arm-none-linux-gnueabi-g++,所以将其改以下即可: using gcc : arm : arm-none-linux-gnueabi-g++; (注意空格和冒号)}
修改文件project-config.jam
# Boost.Build Configuration
# Automatically generated by bootstrap.sh
import option ;
import feature ;
# Compiler configuration. This definition will be used unless
# you already have defined some toolsets in your user-config.jam
# file.
if ! gcc in [ feature.values <toolset> ]
{
using gcc : : /usr/local/arm-linux-androideabi/bin/arm-linux-androideabi-gcc ;
}
project : default-build <toolset>gcc ;
# Python configuration
import python ;
if ! [ python.configured ]
{
using python : 2.7 : "/usr/local/arm-linux-androideabi" ;
}
path-constant ICU_PATH : /usr ;
# List of --with-<library> and --without-<library>
# options. If left empty, all libraries will be built.
# Options specified on the command line completely
# override this variable.
libraries = ;
# These settings are equivalent to corresponding command-line
# options.
option.set prefix : /usr/local ;
option.set exec-prefix : /usr/local ;
option.set libdir : /usr/local/lib ;
option.set includedir : /usr/local/include ;
# Stop on first error
option.set keep-going : false ;
对应交叉编译命令为:
./b2 --without-python --without-mpi --without-serialization link=static runtime-link=static target-os=linux --stagedir=android install --prefix=/home/ubuntu/Downloads/boost_1_73_0/android
文件结构为(预先创建android目录):
ubuntu@ubuntu:~/Downloads/boost_1_73_0/android$ tree -L 2
.
├── include
│ └── boost
└── lib
├── cmake
├── libboost_atomic.a
├── libboost_chrono.a
├── libboost_container.a
├── libboost_context.a
├── libboost_contract.a
├── libboost_coroutine.a
├── libboost_date_time.a
├── libboost_exception.a
├── libboost_fiber.a
├── libboost_filesystem.a
├── libboost_graph.a
├── libboost_iostreams.a
├── libboost_log.a
├── libboost_log_setup.a
├── libboost_math_c99.a
├── libboost_math_c99f.a
├── libboost_math_c99l.a
├── libboost_math_tr1.a
├── libboost_math_tr1f.a
├── libboost_math_tr1l.a
├── libboost_nowide.a
├── libboost_prg_exec_monitor.a
├── libboost_program_options.a
├── libboost_random.a
├── libboost_regex.a
├── libboost_stacktrace_basic.a
├── libboost_stacktrace_noop.a
├── libboost_system.a
├── libboost_test_exec_monitor.a
├── libboost_thread.a
├── libboost_timer.a
├── libboost_type_erasure.a
├── libboost_unit_test_framework.a
└── libboost_wave.a
4 directories, 34 files
修改build.gradle文件,将交叉编译的lib文件和include的头文件复制到对应的Android Studio的文件夹位置;
修改CMakeList.txt文件
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
include_directories(${CMAKE_SOURCE_DIR}/include)
# 导入opencv的so
add_library(boost_date_time STATIC IMPORTED)
set_target_properties(boost_date_time PROPERTIES IMPORTED_LOCATION
${CMAKE_SOURCE_DIR}/../jniLibs/libs/${ANDROID_ABI}/lib/libboost_date_time.a)
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
native-lib.cpp )
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log )
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
target_link_libraries( # Specifies the target library.
native-lib
boost_date_time
# Links the target library to the log library
# included in the NDK.
${log-lib} )
对应的native-lib.cpp文件
#include <jni.h>
#include <string>
#include <iostream>
#include <boost/date_time/gregorian/gregorian.hpp>
using namespace std;
extern "C" JNIEXPORT jstring JNICALL
Java_com_example_boost_MainActivity_stringFromJNI(
JNIEnv* env,
jobject /* this */) {
boost::gregorian::date d(boost::gregorian::day_clock::local_day());
cout <<"year"<< d.year()<<"." << d.month()<<"." <<d.day() <<endl;
std::string hello = "Hello from C++1 2 3 4 ";
return env->NewStringUTF(hello.c_str());
}
测试结果为,给个Android手机特写~~ 哈哈哈哈