tomcat 启用gzip压缩
替换tomcat中的connector，启用compression

<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443" compression="on"     noCompressionUserAgents="gozilla,traviata"     compressableMimeType="text/html,text/xml,text/javascript,text/css,text/plain,application/json,application/x-javascript,image/gif,image/jpeg,image/png,text/html,text/html,application/xhtml+xml,application/xml"    compressionMinSize="2048"     />

运行结果：
未启用情况：
33 个请求 407.4 KB (396.7 KB 来自缓存) 1.72s (onload: 2.45s)

启用后情况：
33 个请求 398.5 KB (396.7 KB 来自缓存) 1.81s (onload: 2.72s)