/**
 * 
 */
package com.air.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;

/**
 * @author jelly_yang
 *
 */
public class SetCharacterEncodingFilter implements Filter {
	
	protected String encoding = null;
	protected FilterConfig filterConfig = null;
	protected boolean ignore = true;
	public void destroy() {
		// TODO Auto-generated method stub
		this.encoding = null;
		this.filterConfig = null;
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		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 {
		// TODO Auto-generated method stub
		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{
			this.ignore = true;
		}
	}
	
	protected String selectEncoding(ServletRequest request){
		return (this.encoding);
	}
	
}