Tomcat7:
URIEncoding
This specifies the character encoding used to decode the URI bytes, after %xx decoding the URL. If not specified, ISO-8859-1 will be used

这个参数用来设置解码url参数，如果没指定，默认是ISO-8859-1。

Tomcat8:
URIEncoding
This specifies the character encoding used to decode the URI bytes, after %xx decoding the URL. If not specified, UTF-8 will be used unless the org.apache.catalina.STRICT_SERVLET_COMPLIANCE system property is set to true in which case ISO-8859-1 will be used.
这个参数用来设置解码url参数，如果没指定，默认是UTF-8，除非设置了org.apache.catalina.STRICT_SERVLET_COMPLIANCE这个系统参数为true，这个时候会使用ISO-8859-1。