package com.guestbook;

import java.io.PrintStream;
//定義類 ，過濾掉字符串中包含的特殊符號 
public class HTMLFilter
{

	public String source;

	public HTMLFilter()
	{
		source = "";
	}

	public void run()
	{
		source = replaceHTML(source);
	}

	private String replaceHTML(String s)
	{
		StringBuffer stringbuffer = new StringBuffer();
		for (int i = 0; i < s.length(); i++)
		{
			char c = s.charAt(i);
			switch (c)
			{
			case 39: // '\''
				stringbuffer.append("&#039;");
				break;

			case 34: // '"'
				stringbuffer.append("&quot;");
				break;

			case 60: // '<'
				stringbuffer.append("&lt;");
				break;

			case 62: // '>'
				stringbuffer.append("&gt;");
				break;

			case 38: // '&'
				stringbuffer.append("&amp;");
				break;

			case 32: // ' '
				stringbuffer.append("&nbsp;");
				break;

			case 10: // '\n'
				stringbuffer.append("<br>");
				break;

			default:
				stringbuffer.append(c);
				break;
			}
		}

		return stringbuffer.toString();
	}

	public void setSource(String s)
	{
		source = s;
	}

	public String getResult()
	{
		return source;
	}

	public static void main(String args[])
	{
		HTMLFilter htmlfilter = new HTMLFilter();
		String s = "abc<>abc";
		htmlfilter.setSource(s);
		htmlfilter.run();
		System.out.println(htmlfilter.source);
		System.out.println(htmlfilter.getResult());
	}
}