不义联盟2怎么换皮肤:这段程序又是哪出错了呢？

package filters;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class LogFilter implements Filter{
FilterConfig filterConfig=null;
public void init(FilterConfig filerConfig) throws ServletException {
this.filterConfig=filterConfig; }
//Process the HTTP Get request
public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws ServletException, IOException {
long startTime = System.currentTimeMillis();
String remoteAddress = request.getRequestDispatcher();
String remoteHost = request.getRemoteHost();
HttpServletRequest httpRequest = (HttpServletRequest) request;
String reqURI = httpRequest.getRequestURI();
String browser = httpRequest.getHeader("User_Agent");
chain.doFilter(request, respose);
long endTime = Systme.currenTimeMillis();
long wordTime = endTime - startTime;
ServletContext sc = filterConfig.getInitParameter("User-Agent");
chain.doFilter(request, response);
long endTime = System.currentTimeMillis();
long wordTime = endTime - startTime;
ServletContext sc = filter.getServletContext();
sc.log("Request from IP:"+remoteAddress +
"(" + remoteHost + ")" + "Using browser(" + browser + ")" +
"and wanted to access resource" + reqURI +
"and used" + wordTime + "ms");

}
public void destroy(){
filerConfig=null;
}
}
提示出错为：
getRequestDispatcher(java.lang.String) in javax.servlet.ServletRequest cannot be applied to () at line 13 (13:36)
cannot resolve symbol: variable respose in class filters.LogFilter at line 18 (18:29)
cannot resolve symbol: variable Systme in class filters.LogFilter at line 19 (19:20)
incompatible types;found : java.lang.String,required: javax.servlet.ServletContext at line 21 (21:54)
endTime is already defined in doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) at line 23 (23:5)
wordTime is already defined in doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) at line 24 (24:5)
sc is already defined in doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) at line 25 (25:5)
cannot resolve symbol: variable filter in class filters.LogFilter at line 25 (25:25)
cannot resolve symbol: variable filerConfig in class filters.LogFilter at line 33 (33:1)
如果没错，那为什么运行不出来！还会提示错误！补充一点：这是一个过滤器！