1、配置一个过滤器，拦截所有请求

package cn.demo.filter;import java.io.IOException;import javax.servlet.Filter;import javax.servlet.FilterChain;import javax.servlet.FilterConfig;import javax.servlet.ServletException;import javax.servlet.ServletRequest;import javax.servlet.ServletResponse;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 全栈乱码过滤器 *  */public class MyFilter implements Filter {	private String value;	private String type;	@Override	public void init(FilterConfig filterConfig) throws ServletException {		value = filterConfig.getInitParameter("encoding");		type = filterConfig.getInitParameter("type");	}	@Override	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)			throws IOException, ServletException {		// 强转成子接口类型，使用更多api		HttpServletRequest httpServletRequest = (HttpServletRequest) request;		HttpServletResponse httpServletResponse = (HttpServletResponse) response;		MyRequest myRequest = new MyRequest(httpServletRequest);// 构造方法注入，MyResquest中重写三个方法，解决乱码		httpServletResponse.setContentType(type + ";charSet=" + value);		chain.doFilter(myRequest, httpServletResponse);	}	@Override	public void destroy() {	}}web.xml配置
    	
    		
     
      MyFilter
     		
     
      cn.demo.filter.MyFilter
     		
     			
      
       encoding
      			
      
       utf-8
      		
     		
     			
      
       type
      			
      
       text/html
      		
     	
    	
    		
     
      MyFilter
     		
     		
     
      /*
     	
    

2、MyRequest类重写三个方法

package cn.demo.filter;import java.io.UnsupportedEncodingException;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletRequestWrapper;public class MyRequest extends HttpServletRequestWrapper {	private HttpServletRequest request;	private boolean flag = false;	public MyRequest(HttpServletRequest request) {		super(request);		this.request = request;	}	// 重写三个方法	@Override	public Map getParameterMap() {		String method = request.getMethod();		if ("post".equalsIgnoreCase(method)) {			try {				request.setCharacterEncoding("utf-8");				return request.getParameterMap();			} catch (UnsupportedEncodingException e) {				// TODO Auto-generated catch block				e.printStackTrace();			}		}		// 遍历取出每个元素，先编码，再解码		if ("get".equalsIgnoreCase(method)) {			if (!flag) {				Map
    
      map = request.getParameterMap();				if (map != null && map.size() != 0) {					// 遍历					for (String key : map.keySet()) {						String[] values = map.get(key);						if (values != null && values.length != 0) {							for (int i = 0; i < values.length; i++) {								try {									// 每一个元素先编码再解码									values[i] = new String(values[i].getBytes("iso-8859-1"), "utf-8");								} catch (UnsupportedEncodingException e) {									// TODO Auto-generated catch block									e.printStackTrace();								}							}						}					}				}				flag = true;				return map;			}		}		return super.getParameterMap();	}	@Override	public String[] getParameterValues(String name) {		Map
     
       map = getParameterMap();		if (map != null && map.size() != 0) {			String[] values = map.get(name);			if (values != null && values.length != 0) {				return values;			}		}		return super.getParameterValues(name);	}	@Override	public String getParameter(String name) {		Map
      
        map = getParameterMap();		if (map != null && map.size() != 0) {			String[] values = map.get(name);			if (values != null && values.length != 0) {				return values[0];			}		}		return super.getParameter(name);	}}