输入11-->在2进制中代表的是3-->在8进制中代表的是9-->在16进制中代表的17

String userCount = User.getUserCount();
//将乱码字符串按照错误的编码格式转换为原始的字节码序列
byte[] bs = userCount.getBytes("iso889-1");
//将原始的字节码序列使用正确的编码格式进行编码，转换为正确的文字
userCount  = new String(bs,"utf-8");

<filter><filter-name>encoding</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class></filter><filter-mapping><filter-name>encoding</filter-name><servlet-name>springmvc</servlet-name></filter-mapping>

public class CharacterEncodingFilter extends OncePerRequestFilter {/*设置了两个属性encoding和forceEncoding，encoding代表的是编码格式，forceEncoding表示是否启用*/private String encoding;private boolean forceEncoding = false;public CharacterEncodingFilter() {}public void setEncoding(String encoding) {this.encoding = encoding;}public void setForceEncoding(boolean forceEncoding) {this.forceEncoding = forceEncoding;}protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {/*当编码格式不为空以及forceEncoding为true时，那么设置就将服务器端的编码格式设置为配置文件中设置的编码格式*/if (this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) {　　　　　　//只能修改请求体中编码方式request.setCharacterEncoding(this.encoding);if (this.forceEncoding) {response.setCharacterEncoding(this.encoding);}}filterChain.doFilter(request, response);}
}

  <filter><filter-name>encoding</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>UTF-8</param-value></init-param><init-param><param-name>forceEncoding</param-name><param-value>true</param-value></init-param></filter><filter-mapping><filter-name>encoding</filter-name><servlet-name>springmvc</servlet-name></filter-mapping>

<Connector URIEncoding="UTF-8" port="8080" protocol="HTTP/1.1"connectionTimeout="20000"redirectPort="8443" />