经过两天的努力,总于在ubuntu以下编译好classpath-0.98与jamvm1.5.4,并能成功的运行类文件:jamvm hellowold,当屏幕上打印出“hello world!”的时候,按捺不住一阵兴奋!在这两天中,运行jamvm hellowold始终被有三类异常:

1) Exceptionoccurred while VM initialising

java/lang/NoClassDefFoundError: java/lang/Thread

2) Exception occured while printing exception(java/lang/NoClassDefFoundError)...

Original exception wasjava/lang/UnsatisfiedLinkError

3)segment fault

对于当中异常1), 2) 我猜測可能是classpath等路径设错,我通过baidu,google,bing等搜索工具查询国内外相关问题,得出一个解决方法是:

通过jamvm –version 命令查询路径信息:

$ jamvm-version

javaversion "1.5.0"

JamVMversion 1.5.4

Copyright(C) 2003-2010 Robert Lougher <[email protected]>

Thisprogram is free software; you can redistribute it and/or

modify itunder the terms of the GNU General Public License

aspublished by the Free Software Foundation; either version 2,

or (atyour option) any later version.

Thisprogram is distributed in the hope that it will be useful,

butWITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITYor FITNESS FOR A PARTICULAR PURPOSE.  Seethe

GNUGeneral Public License for more details.

Buildinformation:

ExecutionEngine: inline-threaded interpreter with stack-caching

Compiledwith: gcc 4.6.3

BootLibrary Path: /usr/local/classpath/lib/classpath

BootClass Path:

/usr/local/jamvm/share/jamvm/classes.zip:/usr/local/classpath/share/classpath/glibj.zip

在运行jamvm helloword之前须要设置两个变量:

export LD_LIBRARY_PATH=/usr/local/classpath/lib/classpath:$LD_LIBRARY_PATH

export  BOOTCLASSPATH=/usr/local/jamvm/share/jamvm/classes.zip:/usr/local/classpath/share/classpath/glibj.zip

可是我依照这样的方法来设置两个环境变量,还是解决不了问题;

关于异常3) 这个一定是jamvm本身的bug,除非单步调试,否则可能无法定位其问题,况且即使定位,也绝对无法解决。

在一筹莫展之时,突然搜索到一篇国际友人帖子,该贴对我的成功起了决定性的作用,真是山重水复疑无路,柳暗花明又一村!!!感谢该贴的作者!url例如以下:

http://www.webos-internals.org/wiki/Building_JamVM_and_GNU_Classpath_and_Jikes_(for_Java_support_in_webOS)_with_scratchbox2

详细来说,该文提到一个非常关键的地方,就是在编jamvm的时候,须要enable libffi模块,否则会引起段错误!

我依照该文的步骤,一步一步走下来,终于得到了自己想要的结果!该文的应该用场景是arm,而且能够带gui,gtk等应用,而我的应用场景比較简单,即在x86以下不带gui的应用,故而我的编译和他有一些区别,详细过程例如以下:

1.       classpath相关操作

$ cd ~/work/free

$ wget ftp://ftp.gnu.org/gnu/classpath/classpath-0.98.tar.gz

$ tar xzvf classpath-0.98.tar.gz

$ cd classpath-0.98

$ ./configure--disable-examples --without-x --disable-qt-peer --disable-gtk-peer--disable-gconf-peer --disable-plugin --disable-alsa --disable-dssi

$ make -i

$ sudo make install -i

注: classpath的默认安装路径为/usr/local/classpath

2.       jamvm相关操作

$ cd ~/work/free

$ wget ftp://sourceware.org/pub/libffi/libffi-3.0.10.tar.gz

$ tar xzvf libffi-3.0.10.tar.gz

$ cd libffi-3.0.10

$ ./configure--prefix=/usr/local

$ make

$ sudo make install

$ sudo cp include/ffi_common.h /usr/local/include/

$cd i686-pc-linux-gnu/

$ cd include/

$ sudo cp ffi.h /usr/local/include

$ cd ../src/86

$ sudo cp ffitarget.h /usr/local/include

$ cd ~/work/free

$ wget http://freefr.dl.sourceforge.net/project/jamvm/jamvm/JamVM%201.5.4/jamvm-1.5.4.tar.gz

$ tar xzvf jamvm-1.5.4.tar.gz

$ cd jamvm-1.5.4

$ CPPFLAGS="-I/usr/local/include"

$ ./configure --with-classpath-install-dir=/usr/local/classpath -enable-ffi

$ make

$ sudo make install

3.       验证jamvm

1> 已知源码~/work/free/jamvm-1.5.4/java/helloworld.java:

public class helloworld {

    public static void main(String[] args) {

        System.out.println(“hello world!”);

    }

}

2> 编译 javac helloworld.java

生产helloworld.class

3> 运行jamvm helloworld 打印结果:

helloworld!

此时我们在查看CLASSPATH, LD_LIBRARY_PATH,发现:

lihan@master:~$echo $CLASSPATH

lihan@master:~$echo $LD_LIBRARY_PATH

:/usr/local/lib

cd ~/work/free/jamvm-1.5.4/java/

lihan@master:~/work/free/jamvm-1.5.4/java$jamvm helloworld

helloworld!

能够看到,CLASSPATH与LD_LIBRARY_PATH并不须要设置成之前说的, jamvm –version显示的那些路径!!!

最后,希望该文能对遇到相同问题的兄弟们起到一定帮助!

04-13 13:33