String将字符串中的 \ 替换成 \\

public static void main(String[] args) {
		String str = "D:\\Programs Files\\apache-tomcat-6.0.29\\webapps\\BookShop\\headImage\\zhuleishitou10.gif";
		System.out.println(str);
		String string="";
		String filter = (char) '\\' + "\\";
		for (int i = 0; i < str.toCharArray().length; i++) {
			if (!String.valueOf(str.toCharArray()[i]).equals("\\")) {
				string+=str.toCharArray()[i];
			}else{
				string+=filter;
			}
		}
		System.out.println(string);
	}