htmlspecialcharater.java

这是一个网上考试系统,主要是用java和jsp写的.

package kaoshi.bean;

/**
 * @version 2008-1-3
 * @author Xiaofei 
 */
public class HtmlSpecialCharater {
	
	public static String filter(String input) {
		/*
		if (!hasSpecialChars(input)) {
			return input;
		}
		*/
		StringBuffer filtered = new StringBuffer(input.length());
		char c;
		for (int i=0; i<input.length(); i++) {
			c = input.charAt(i);
			switch (c) {
				case '<': filtered.append("&lt;"); break;
				case '>': filtered.append("&gt;"); break;
				case '"': filtered.append("&quot;"); break;
				case '&': filtered.append("&amp;"); break;
				default: filtered.append(c);
			}
		}
		return filtered.toString();
	}
	
	public static boolean hasSpecialChars(String input) {
		boolean flag = false;
		if ((input!=null)&&(input.length()>0)) {
			char c;
			for (int i=0; i<input.length(); i++) {
				c = input.charAt(i);
				switch (c) {
					case '<': flag = true; break;
					case '>': flag = true; break;
					case '"': flag = true; break;
					case '&': flag = true; break;
				}
			}
		}
		return flag;
	}
		
}