How：java串口配置(安装javax.comm)

1.Download and unpack the javacomm20-win32.zip ,then we get directory "commapi"

2.open directory commapi copy win32com.dll to <jdk>\jre\bin directory

3.copy the comm.jar to <jdk>\jre\lib\ext directory

4.copy the javax.comm.properties to <jdk>\jre\lib

5.do not need to alter the classpath