cmake java demo项目无法使用我的MANIFEST.MF创建“jar”

Question

我有一个非常简单的cmake java项目

（1）CMakeLists.txt：

cmake_minimum_required (VERSION 2.8)
find_package(Java)
include(UseJava)
enable_testing()

project (HelloWorld)
set(CMAKE_JAVA_COMPILE_FLAGS "-source" "1.8" "-target" "1.8")
set(CMAKE_JAVA_MANIFEST MANIFEST.MF)
add_jar(HelloWorld HelloWorld.java)

get_target_property(_jarFile HelloWorld JAR_FILE)
get_target_property(_classDir HelloWorld CLASSDIR)
message(STATUS "Jar file ${_jarFile}")
message(STATUS "Class compiled to ${_classDir}")

(2) HelloWorld.Java

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

（3）MANIFEST.MF

Manifest-Version: 1.0
Extension-Name: My
Implementation-Version: 1.1
Main-Class: HelloWorld

（4）cmake。 && make

-- Jar file /root/mynet/mytest/build/useCmake/forJava/HelloWorld.jar
-- Class compiled to /root/mynet/mytest/build/useCmake/forJava/CMakeFiles/HelloWorld.dir
-- Configuring done
-- Generating done
-- Build files have been written to: /root/mynet/mytest/build/useCmake/forJava
/usr/bin/cmake -H/root/mynet/mytest/build/useCmake/forJava -B/root/mynet/mytest/build/useCmake/forJava --check-build-system CMakeFiles/Makefile.cmake 0
/usr/bin/cmake -E cmake_progress_start /root/mynet/mytest/build/useCmake/forJava/CMakeFiles /root/mynet/mytest/build/useCmake/forJava/CMakeFiles/progress.marks
make -f CMakeFiles/Makefile2 all
make[1]: Entering directory '/root/mynet/mytest/build/useCmake/forJava'
make -f CMakeFiles/HelloWorld.dir/build.make CMakeFiles/HelloWorld.dir/depend
make[2]: Entering directory '/root/mynet/mytest/build/useCmake/forJava'
cd /root/mynet/mytest/build/useCmake/forJava && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /root/mynet/mytest/build/useCmake/forJava /root/mynet/mytest/build/useCmake/forJava /root/mynet/mytest/build/useCmake/forJava /root/mynet/mytest/build/useCmake/forJava /root/mynet/mytest/build/useCmake/forJava/CMakeFiles/HelloWorld.dir/DependInfo.cmake --color=
make[2]: Leaving directory '/root/mynet/mytest/build/useCmake/forJava'
make -f CMakeFiles/HelloWorld.dir/build.make CMakeFiles/HelloWorld.dir/build
make[2]: Entering directory '/root/mynet/mytest/build/useCmake/forJava'
make[2]: Nothing to be done for 'CMakeFiles/HelloWorld.dir/build'.
make[2]: Leaving directory '/root/mynet/mytest/build/useCmake/forJava'
[100%] Built target HelloWorld
make[1]: Leaving directory '/root/mynet/mytest/build/useCmake/forJava'
/usr/bin/cmake -E cmake_progress_start /root/mynet/mytest/build/useCmake/forJava/CMakeFiles 0

好的，事情看起来不错，但是

java -jar HelloWorld.jar
no main manifest attribute, in HelloWorld.jar

我在罐子里检查了META-INF / MANIFEST.MF，这不是我自己的清单：

jar tvf HelloWorld.jar
     0 Tue Feb 19 03:56:08 GMT 2019 META-INF/
    69 Tue Feb 19 03:56:08 GMT 2019 META-INF/MANIFEST.MF
   427 Tue Feb 19 03:49:20 GMT 2019 HelloWorld.class

它只包含2行：

Manifest-Version: 1.0
Created-By: 1.8.0_191 (Oracle Corporation)

所以我的清单文件似乎没有生效。怎么解决？非常感谢

Answer 1

根据cmake documentation：

要为jar定义自定义清单，可以使用manifest命名参数设置它：

add_jar(example MANIFEST /path/to/manifest)

但请注意，我从未听说有人使用cmake来构建Java代码。

看看maven，ivy或gradle - 他们得到了积极的支持和发展。