jttvideo/src/native/CMakeLists.txt

# CMake project for JNI wrapper
cmake_minimum_required(VERSION 3.20)
project(aac_jni LANGUAGES C)

add_library(aac_jni SHARED aac_jni.c)

# 自动处理 JAVA_HOME（跨平台）
# 1) 命令行 -DJAVA_HOME 传入优先
# 2) 环境变量 JAVA_HOME 其次
# 3) find_package(Java) 自动探测兜底
set(JAVA_HOME "" CACHE PATH "Path to JDK home")
if(NOT JAVA_HOME AND DEFINED ENV{JAVA_HOME})
  set(JAVA_HOME "$ENV{JAVA_HOME}")
endif()
if(NOT JAVA_HOME)
  find_package(Java COMPONENTS Development)
  # 可兼容多版本JDK；如需限定最低版本，可启用如下检查：
  # if(DEFINED Java_VERSION_STRING AND Java_VERSION_STRING VERSION_LESS 17)
  #   message(FATAL_ERROR "需要 JDK 17 及以上，当前: ${Java_VERSION_STRING}")
  # endif()
  if(Java_FOUND AND Java_JAVAC_EXECUTABLE)
    get_filename_component(_javac_dir "${Java_JAVAC_EXECUTABLE}" DIRECTORY)
    get_filename_component(JAVA_HOME "${_javac_dir}/.." ABSOLUTE)
    set(JAVA_HOME "${JAVA_HOME}" CACHE PATH "Path to JDK home" FORCE)
  endif()
endif()
if(NOT JAVA_HOME)
  message(FATAL_ERROR "JAVA_HOME 未设置。请通过 -DJAVA_HOME=... 或设置环境变量 JAVA_HOME，或确保 CMake 能自动探测到 JDK。")
endif()
message(STATUS "Using JAVA_HOME: ${JAVA_HOME}")

# 平台相关配置
if(WIN32)
    # Windows 平台配置
    set(PLATFORM_DIR "win32")
    set(NATIVE_PLATFORM_DIR "windows/x64")
    set(FDK_AAC_LIB "${CMAKE_SOURCE_DIR}/../../native/windows/x64/Release/fdk-aac.lib")
    
    # 为了避免绝对路径引用，将 JDK 头文件复制到构建目录下的相对路径
    set(JDK_LOCAL_INCLUDE_DIR "${CMAKE_BINARY_DIR}/jdk/include")
    set(JDK_LOCAL_PLATFORM_INCLUDE_DIR "${JDK_LOCAL_INCLUDE_DIR}/${PLATFORM_DIR}")
    file(MAKE_DIRECTORY "${JDK_LOCAL_INCLUDE_DIR}")
    file(MAKE_DIRECTORY "${JDK_LOCAL_PLATFORM_INCLUDE_DIR}")
    file(COPY "${JAVA_HOME}/include/" DESTINATION "${JDK_LOCAL_INCLUDE_DIR}")
    file(COPY "${JAVA_HOME}/include/${PLATFORM_DIR}/" DESTINATION "${JDK_LOCAL_PLATFORM_INCLUDE_DIR}")
    
    # Windows 包含目录
    target_include_directories(aac_jni PRIVATE
        "${JDK_LOCAL_INCLUDE_DIR}"
        "${JDK_LOCAL_PLATFORM_INCLUDE_DIR}"
        "${CMAKE_SOURCE_DIR}/../../native/include/fdk-aac"
    )
    
    # Windows 链接库
    target_link_libraries(aac_jni PRIVATE
        "${FDK_AAC_LIB}"
    )
    
    # Windows 输出目录
    set_target_properties(aac_jni PROPERTIES
        OUTPUT_NAME "aac_jni"
        RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/../../native/windows/x64/"
    )
    
    # 让 MSVC 以 UTF-8 编译，避免 C4819 警告
    target_compile_options(aac_jni PRIVATE "$<$<C_COMPILER_ID:MSVC>:/utf-8>")
elseif(UNIX AND NOT APPLE)
    # Linux 平台配置
    set(PLATFORM_DIR "linux")
    set(NATIVE_PLATFORM_DIR "linux")
    
    # 确保 JDK 头文件路径正确
    set(JDK_INCLUDE_DIR "${JAVA_HOME}/include")
    set(JDK_PLATFORM_INCLUDE_DIR "${JDK_INCLUDE_DIR}/${PLATFORM_DIR}")
    
    # 验证 JDK 头文件路径是否存在
    if(NOT EXISTS "${JDK_INCLUDE_DIR}/jni.h")
        message(WARNING "JNI 头文件 jni.h 未找到在 ${JDK_INCLUDE_DIR}")
        # 尝试常见的 Linux JDK 路径
        set(ALTERNATIVE_JDK_PATHS
            "/usr/lib/jvm/default/include"
            "/usr/lib/jvm/java-11-openjdk-amd64/include"
            "/usr/lib/jvm/java-17-openjdk-amd64/include"
        )
        foreach(ALT_PATH IN LISTS ALTERNATIVE_JDK_PATHS)
            if(EXISTS "${ALT_PATH}/jni.h")
                set(JDK_INCLUDE_DIR "${ALT_PATH}")
                set(JDK_PLATFORM_INCLUDE_DIR "${JDK_INCLUDE_DIR}/${PLATFORM_DIR}")
                message(STATUS "找到替代 JDK 头文件路径: ${JDK_INCLUDE_DIR}")
                break()
            endif()
        endforeach()
    endif()
    
    # Linux 包含目录
    target_include_directories(aac_jni PRIVATE
        "${JDK_INCLUDE_DIR}"
        "${JDK_PLATFORM_INCLUDE_DIR}"
        "${CMAKE_SOURCE_DIR}/../../native/include/fdk-aac"
    )
    
    # Linux 链接库 - 尝试多种可能的库文件路径
    set(FDK_AAC_LIB_PATHS
        "${CMAKE_SOURCE_DIR}/../../native/linux/libfdk-aac.so"
        "/usr/lib/x86_64-linux-gnu/libfdk-aac.so"
        "/usr/lib/libfdk-aac.so"
    )
    
    # 查找存在的 fdk-aac 库
    foreach(LIB_PATH IN LISTS FDK_AAC_LIB_PATHS)
        if(EXISTS "${LIB_PATH}")
            set(FDK_AAC_LIB "${LIB_PATH}")
            message(STATUS "找到 fdk-aac 库: ${FDK_AAC_LIB}")
            break()
        endif()
    endforeach()
    
    # 如果找不到库文件，尝试使用系统库
    if(NOT DEFINED FDK_AAC_LIB)
        message(STATUS "未找到预编译的 fdk-aac 库，尝试使用系统库")
        find_library(FDK_AAC_LIB NAMES fdk-aac)
        if(FDK_AAC_LIB)
            message(STATUS "找到系统 fdk-aac 库: ${FDK_AAC_LIB}")
        else()
            message(FATAL_ERROR "未找到 fdk-aac 库，请确保已安装或放置在正确位置")
        endif()
    endif()
    
    # 链接库
    target_link_libraries(aac_jni PRIVATE
        "${FDK_AAC_LIB}"
    )
    
    # Linux 输出目录
    set_target_properties(aac_jni PROPERTIES
        OUTPUT_NAME "aac_jni"
        LIBRARY_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/../../native/linux/"
    )
    
    # Linux 编译选项
    target_compile_options(aac_jni PRIVATE
        -fPIC
        -Wall
        -Wextra
        -Wpedantic
        -std=c99  # 使用 C99 标准，确保 size_t 等类型正确定义
    )
else()
    message(FATAL_ERROR "当前平台不支持。支持的平台：Windows 和 Linux。")
endif()