特殊符号转义 （<， &lt ...）

public static String htmlReplace(String str){
str = str.replace("“","“");
str = str.replace("”","”");
str = str.replace(" ","”");
str = str.replace("&","&");
str = str.replace("'","'");
str = str.replace("’","’");
str = str.replace("—","—");
str = str.replace("–","–");
str = str.replace("<","&lt;");
str = str.replace(">","&gt;");
return str;
}

后台实现 

public static String htmlEncode(String source) {
if (source == null) {
return "";
}
String html = "";
StringBuffer buffer = new StringBuffer();
for (int i = 0; i < source.length(); i++) {
char c = source.charAt(i);
switch (c) {
case '<':
buffer.append("<");
break;
case '>':
buffer.append(">");
break;
case '&':
buffer.append("&");
break;
case '"':
buffer.append(""");
break;
case 10:
case 13:
break;
default:
buffer.append(c);
}
}
html = buffer.toString();
return html;
}