Java Web 乱码过滤器 filter

大家都知道，在jsp里乱码是最让人讨厌的东西，有些乱码出来的莫名其妙，给开发带来很大困扰，但搞一个乱码过滤器就一切都解决了，配置好之后，你并不需要在页面里进行转码之类的。

  首先，写一个过滤器类，如下：

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;
import javax.servlet.http.HttpServletRequest;

public class PageEncodingFilter implements Filter{

    private String encoding = "UTF-8";
    protected FilterConfig filterConfig;


    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
        //本过滤器默认编码是UTF-8，但也可以在web.xml配置文件里设置自己需要的编码
        if(filterConfig.getInitParameter("encoding") != null)
            encoding = filterConfig.getInitParameter("encoding");
    }

    public void doFilter(ServletRequest srequset, ServletResponse sresponse,
            FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)srequset;
        request.setCharacterEncoding(encoding);
        filterChain.doFilter(srequset, sresponse);
    }

    public void destroy() {
        this.encoding = null;
    }

}

 

  然后，在web.xml里配置，如下：

 

<filter>
        <filter-name>Encoding</filter-name>
        <filter-class>filter.PageEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>Encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

 

  到这里，一切就OK了，你可以放心的写代码了，而不会担心出现乱码了。