myfilter.java

学生信息管理系统

package 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 diaoyifei
 *
 * 过滤器，设置字符集
 */
public class MyFilter implements Filter
{
    /** 字符集 */
    protected String        encoding        = "GBK";
    protected FilterConfig  filterConfig    = null;

    public void setFilterConfig(FilterConfig config)
    {
        this.filterConfig = config;
    }

    public FilterConfig getFilterConfig()
    {
        return filterConfig;
    }

    protected String selectEncoding(ServletRequest request)
    {
        return (this.encoding);
    }


    /**
     * 过滤
     */
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException
    {
        //设字符集
        String encoding = selectEncoding(request);
        if (encoding != null)
        {
            request.setCharacterEncoding(encoding);
        }
        
        //下一个过滤器
        chain.doFilter(request, response);

    }
    
    /**
     * 初始化
     */
    public void init(FilterConfig filterConfig) throws ServletException
    {
        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
    }

    /**
     * 销毁
     */
    public void destroy()
    {
        this.encoding = null;
        this.filterConfig = null;
    }
}