JAVA_WEB 编码格式过滤器

Posted 2020-10-19 wanrenor

过滤器的作用:
对于整个项目进行统一编码格式的统一,假如项目有很多页面获取值 则需要每个页面都要设置编码格式,这这时候就要设置过滤器了,配置如下
需要用到:  EncodingFilter java类;和web.xml
1.读取web.xml 文件中配置的WEB 应用初始化参数encoding
2.指定请求的字符编码为1 读取到的编码;
3.调用chain.doFilter()方法 "执行"请求
request.setCharacterEncoding("UTF-8");

package cn.hp.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 EncodingFilter implements Filter {
	String encoding = "";

	@Override
	public void destroy() {
		// TODO Auto-generated method stub

	}

	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {
		// TODO Auto-generated method stub
		res.setCharacterEncoding(encoding);
		req.setCharacterEncoding(encoding);
		chain.doFilter(req, res);
	}

	@Override
	public void init(FilterConfig config) throws ServletException {
		// TODO Auto-generated method stub
		encoding = config.getInitParameter("encoding");
	}

}

　　web.xml 配置文件: 

 1     <!-- 编码格式过滤器 -->
 2     <filter>
 3         <filter-name>EncodingFilter</filter-name>
 4         <filter-class>cn.hp.filter.EncodingFilter</filter-class>
 5         <init-param>
 6             <param-name>encoding</param-name>
 7             <param-value>UTF-8</param-value>
 8         </init-param>
 9     </filter>
10     <filter-mapping>
11         <filter-name>EncodingFilter</filter-name>
12         <url-pattern>/*</url-pattern>
13     </filter-mapping>