charsetfilter.java

web页面验证码

package com.scitel.checkDemo.web;

import java.io.IOException;
import java.io.PrintWriter;

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.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CharsetFilter implements Filter{

	  private FilterConfig config = null;
	  private String targetEncoding = "ASCII";

	  public void init(FilterConfig config) throws ServletException {
	    this.config = config;
	    this.targetEncoding = config.getInitParameter("encoding");
	  }

	  public void destroy() {
	    config = null;
	    targetEncoding = null;
	  }

	  public void doFilter(ServletRequest srequest, ServletResponse sresponse,
	                       FilterChain chain) throws IOException, ServletException {
	    HttpServletRequest request = (HttpServletRequest) srequest;
	    request.setCharacterEncoding(targetEncoding);
	    chain.doFilter(srequest, sresponse);
	  }

}