RequestParameterFilter

package com.test.tony.filter;

import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
*打出请求参数
*/
public class RequestParameterFilter implements Filter {
	public void destroy() {
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
			ServletException {
		Map map = request.getParameterMap();
		Set set = map.keySet();
		Iterator it = set.iterator();
		String paramName = null;
		while (it.hasNext()) {
			paramName = (String) it.next();
			String values[] = request.getParameterValues(paramName);
			for (int i = 0; i < values.length; i++) {
				System.out.println("Parameter:   " + paramName + " ---> " + values[i]);
			}
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig config) throws ServletException {
	}

}


WEB.XML配置：
	<filter>
		<filter-name>requestParameter</filter-name>
		<filter-class>com.test.tony.filter.RequestParameterFilter</filter-class>
	</filter>

	<filter-mapping>
		<filter-name>requestParameter</filter-name>
		<url-pattern>*</url-pattern>
	</filter-mapping>