java过滤器处理中文乱码简单应用

一、首先呢先建一个普通类 ，并且实现Filter接口

如下所示

 

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;

/**
 * 过滤器类
 * @author 
 *
 */
public class EncodeFilter implements Filter {
    private String encode=null;
    @Override
    public void destroy() {
        encode=null;
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        if(null==request.getCharacterEncoding()){
            request.setCharacterEncoding(encode);
        }
        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        String encode=filterConfig.getInitParameter("encode");
        if(this.encode==null){
            this.encode=encode;//查找配置文件中预设的字符编码
        }
        
    }

}

二、要在当前项目的web.xml文件下配置

如下标签、

其中/*表示过滤所有

 

<filter>
      <filter-name>EncodeFilter</filter-name>
      <filter-class>org.news.filter.EncodeFilter</filter-class>
      <init-param>
          <param-name>encode</param-name>
          <param-value>UTF-8</param-value>
      </init-param>
  </filter>
  <filter-mapping>
      <filter-name>EncodeFilter</filter-name>
      <url-pattern>/*</url-pattern>
  </filter-mapping>