在表單提交文字時，文字內容本身可能就是一段html格式內容，因此要是不做轉義直接顯示在網頁上時，將會被當做一段html文字進行顯示，這就和本身提交的內容不符，因此可以對request物件進行增強，是提交的資料按其原格式進行顯示。下面是個MyHtmlRequest包裝類，其中filter方法是tomcat中HtmlFilter.java裡的一段原始碼。

public class MyHtmlRequest extends HttpServletRequestWrapper {
	private HttpServletRequest request;
	
	public MyHtmlRequest(HttpServletRequest request) {
		super(request);
		// TODO Auto-generated constructor stub
		this.request = request;
	}
	
	
	 /* (non-Javadoc)
	 * @see javax.servlet.ServletRequestWrapper#getParameter(java.lang.String)
	 */
	@Override
	public String getParameter(String name) {
		// TODO Auto-generated method stub
		String value = request.getParameter(name);
		if(value==null){
			return null;
		}
		
		return filter(value);
	}


	public 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());

	    }
}
 

@Override
	public void doFilter(ServletRequest req, ServletResponse resp,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		
		HttpServletRequest request = (HttpServletRequest)req;
		HttpServletResponse response = (HttpServletResponse)resp;
		MyHtmlRequest myReq = new MyHtmlRequest(request);
		chain.doFilter(myReq, response);
	}