Linux下JDK汉字显示为方框

解决方法如下：

1、在windows的字体目录拷贝simsun.ttf文件（如果是simsun.ttc你就复制成ttf吧）到JDK字体目录

#cp simsun.ttf $JAVA_HOME/jre/lib/fonts

如果你的系统用simsun汉化过，这里添加一个simsun字体文件的软链接也可以。

2、修改$JAVA_HOME/jre/lib/fonts/fonts.dir(此文件为只读，需要修改属性才能修改)文件内容，记得要先做个备份呀，将每行的原来的字体改成simsun.ttf吧

以下有个例子：

 48
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-1
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-1
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-1
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-2
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-2
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-2
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-4
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-4
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-4
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-5
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-5
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-5
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-7
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-7
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-7
simsun.ttf -b&h-lucidabright-medium-r-normal--0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidabright-medium-i-normal--0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidabright-demibold-r-normal--0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidabright-demibold-i-normal--0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidasans-medium-r-normal-sans-0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidasans-bold-r-normal-sans-0-0-0-0-p-0-iso8859-9
simsun.ttf -b&h-lucidatypewriter-medium-r-normal-sans-0-0-0-0-m-0-iso8859-9
simsun.ttf -b&h-lucidatypewriter-bold-r-normal-sans-0-0-0-0-m-0-iso8859-9

可以使用vi来一次全部替换 :%s/.*ttf/simsun.ttf

3、再次启动JAVA程序，界面就能显示中文了。