HTML特殊字符过滤器

package com.pdsu.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; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.HttpServletResponse; /** * 类说明：HTML特殊字符过滤器 * * @author 作者: LiuJunGuang * @version 创建时间：2011-11-18 下午07:36:44 */ public class HTMLCharacterFilter implements Filter { public void init(FilterConfig filterConfig) throws ServletException { } public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest) req; HttpServletResponse response = (HttpServletResponse) resp; chain.doFilter(new HTMLCharacterRequest(request), response); } public void destroy() { } } // html特殊字符处理类 class HTMLCharacterRequest extends HttpServletRequestWrapper { public HTMLCharacterRequest(HttpServletRequest request) { super(request); } @Override public String getParameter(String name) { return filter(super.getParameter(name)); } /** * 对特殊的html字符进行编码 * * @param message * @return */ private String filter(String message) { if (message == null) return (null); char content[] = new char[message.length()]; message.getChars(0, message.length(), content, 0); StringBuilder result = new StringBuilder(content.length + 50); for (int i = 0; i < content.length; i++) { switch (content[i]) { case '<': result.append("&lt;"); break; case '>': result.append("&gt;"); break; case '&': result.append("&amp;"); break; case '"': result.append("&quot;"); break; default: result.append(content[i]); } } return (result.toString()); } }

在web.xml中添加如下内容：

<!-- HTML特殊字符过滤器 --> <filter> <filter-name>HTMLFiter</filter-name> <filter-class>com.pdsu.filter.HTMLCharacterFilter</filter-class> </filter> <filter-mapping> <filter-name>HTMLFiter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>