我把服务器的下面配置换一下就可以了：
下载这个压缩包：mfz-rxtx-2.2-20081207-linux-x86_64
解压会有下面的文件
Windows
----------------------------------------------------
Choose your binary build - x64 or x86 (based on which version of
the JVM you are installing to)
NOTE: You MUST match your architecture. You can't install the i386
version on a 64-bit version of the JDK and vice-versa.
For a JDK installation:
Copy RXTXcomm.jar ---> <JAVA_HOME>\jre\lib\ext
Copy rxtxSerial.dll ---> <JAVA_HOME>\jre\bin
Copy rxtxParallel.dll ---> <JAVA_HOME>\jre\bin
Linux
----------------------------------------------------
Choose your binary build - x86_64 or i386 (based on which version of
the JVM you are installing to)
NOTE: You MUST match your architecture. You can't install the i386
version on a 64-bit version of the JDK and vice-versa.
For a JDK installation on architecture=i386
Copy RXTXcomm.jar ---> <JAVA_HOME>/jre/lib/ext
Copy librxtxSerial.so ---> <JAVA_HOME>/jre/lib/i386/
Copy librxtxParallel.so ---> <JAVA_HOME>/jre/lib/i386/
NOTE: For a JDK installation on architecture=x86_64, just change the
i386 to x86_64 above.
按照上面官方给出的说明，把文件放到对应位置，然后重启项目；
注意：如果Linux jdk没有i386这个问题，有amd64，则是下载上面的压缩包，并且把.so文件放到amd64文件夹里面。
具体下载那个压缩包，输入：uname -r，如果输出Linux内核是x86_64，那么应该下载x86_64
