setcharsetencodingfilter.java

学校的课程管理及选课系统

package org.wangsong.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;

public class SetCharsetEncodingFilter implements Filter
{
    protected String encoding =null;
    protected FilterConfig filterConfig=null;
    protected boolean ignore =true;
	
	
	public void destroy()
	{
		 this.encoding=null;
		 this.filterConfig=null;

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException
	{
		 if(ignore||(request.getCharacterEncoding()==null))
		 {
			 String encoding =selectEncoding(request);
			 if(encoding!=null)
				 request.setCharacterEncoding(encoding);
				 
		 }
		 chain.doFilter(request, response);
			 
			 

	}

	public void init(FilterConfig filterConfig) throws ServletException
	{
		 this.filterConfig=filterConfig;
		 this.encoding=filterConfig.getInitParameter("encoding");
		 String value=filterConfig.getInitParameter("ignore");
		 if(value==null)
		 {
			 this.ignore=true; 
		 }
		 else if(value.equalsIgnoreCase("true"))
			 this.ignore=true;
		 else if(value.equalsIgnoreCase("yes"))
			 this.ignore=true;
		 else
			   this.ignore=false;
	}
	
	protected String selectEncoding(ServletRequest request)
	{
		return this.encoding;
	}

}