Fileter类的引用(web.xml中更改编码)

最新推荐文章于 2023-03-20 15:13:42 发布

原创最新推荐文章于 2023-03-20 15:13:42 发布 · 200 阅读

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#xml #web

本文档描述了如何在Java Web应用中创建一个自定义的过滤器`CharaterEncodingFilter`，该过滤器用于设置请求和响应的字符编码。过滤器实现了`javax.servlet.Filter`接口，并在`web.xml`中配置，以确保整个应用使用UTF-8编码。在初始化时，过滤器从配置中获取编码值，并在请求和响应中设置该编码。

1.创建fileter包

2.创建接口Fileter.java继承 javax.servlet.Filter

3.创建CharaterEncodingFilter.java实现Fileter

package filter;

import java.io.IOException;

import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class CharaterEncodingFilter implements Filter {
	String bianma = null;// 保存从web.xml文件中获取的encode这个变量的值

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

	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse resoResponse, FilterChain filterChain)
			throws IOException, ServletException {
		// 获取编码
		String r = request.getCharacterEncoding();
		String ron = resoResponse.getCharacterEncoding();
		// 赋值
		if (r == null) {
			request.setCharacterEncoding(bianma);
		}
		if (ron == null) {
			resoResponse.setCharacterEncoding(bianma);
		}
		// 输出
		resoResponse.setContentType("text/html;charset=" + bianma);
		filterChain.doFilter(request, resoResponse);
		// TODO Auto-generated method stub

	}

	@Override
	// 初始化编码
	public void init(FilterConfig filterConfig) throws ServletException {
		bianma = filterConfig.getInitParameter("encode");

	}

}

4.配置web.xml文件

<filter>

   <filter-name>a</filter-name>
   <filter-class>filter.CharaterEncodingFilter</filter-class>
   <init-param>
   <param-name>encode</param-name>
   <param-value>UTF-8</param-value>
   </init-param>
</filter>
<filter-mapping>
<filter-name>a</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>