默认情况下，Tomcat对请求采用的默认编码是ISO-8859-1
一、修改 Tomcat 配置文件
conf/server.xml
useBodyEncodingForURI="true" URIEncoding="UTF-8"
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443"
useBodyEncodingForURI="true" URIEncoding="UTF-8"/>
String提供的编码转化
String str = new String(str .getBytes(“ISO8859-1”),“UTF-8”).trim();
