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));
}
@Override
public String[] getParameterValues(String name) {
String[] values = super.getParameterValues(name);
if (values == null || values.length == 0)
return values;
for (int i = 0; i < values.length; i++) {
String str = values[i];
values[i] = filter(str);
}
return values;
}
/**
* 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("<");
break;
case '>':
result.append(">");
break;
case '&':
result.append("&");
break;
case '"':
result.append(""");
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>
