Filter过滤器的代码
package cn.yellowimg.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.annotation.WebFilter; import javax.servlet.http.HttpServletRequest; /** * Servlet Filter implementation class EncodingFilter */ //过滤全站 @WebFilter("/*") public class EncodingFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { HttpServletRequest rq = (HttpServletRequest)request; //解决post编码问题 if(rq.getMethod().equals("POST")) { rq.setCharacterEncoding("utf-8"); chain.doFilter(rq, response); } //解决get编码问题 else { //调包request 装饰者模式 EncodingRequest eq = new EncodingRequest(rq); chain.doFilter(eq, response); } } public void init(FilterConfig fConfig) throws ServletException { } }调包request（即增强request中的getParameter()方法）
package cn.yellowimg.filter; import java.io.UnsupportedEncodingException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; //继承tomcat提供的HttpServletRequestWrapper，增强request public class EncodingRequest extends HttpServletRequestWrapper { HttpServletRequest httpServletRequest; public EncodingRequest(HttpServletRequest request) { super(request); this.httpServletRequest = request; } @Override //重写getParameter方法，将iso-8859-1专成utf-8编码 public String getParameter(String name) { String value = super.getParameter(name); try { value = new String(value.getBytes("iso-8859-1"), "utf-8"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } return value; } }