我想要以下格式的方法:
public boolean isValidHtmlEscapeCode(String string);
用法是:
isValidHtmlEscapeCode("A") == false
isValidHtmlEscapeCode("ש") == true // Valid unicode character
isValidHtmlEscapeCode("ש") == true // same as 1513 but in HEX
isValidHtmlEscapeCode("�") == false // Invalid unicode character
我找不到任何可以做到的东西 - 有没有做到这一点的实用程序?如果没有,有什么明智的方法吗?
public static boolean isValidHtmlEscapeCode(String string) {
if (string == null) {
return false;
}
Pattern p = Pattern
.compile("&(?:#x([0-9a-fA-F]+)|#([0-9]+)|([0-9A-Za-z]+));");
Matcher m = p.matcher(string);
if (m.find()) {
int codePoint = -1;
String entity = null;
try {
if ((entity = m.group(1)) != null) {
if (entity.length() > 6) {
return false;
}
codePoint = Integer.parseInt(entity, 16);
} else if ((entity = m.group(2)) != null) {
if (entity.length() > 7) {
return false;
}
codePoint = Integer.parseInt(entity, 10);
} else if ((entity = m.group(3)) != null) {
return namedEntities.contains(entity);
}
return 0x00 <= codePoint && codePoint < 0xd800
|| 0xdfff < codePoint && codePoint <= 0x10FFFF;
} catch (NumberFormatException e) {
return false;
}
} else {
return false;
}
}
这是一组命名实体http://pastebin.com/xzzmydjf
您可能想看看Apache Commons stringutils:http://commons.apache.org/lang/api-2.3/org/apache/commons/lang/stringescapeutils.html#un.unescapehtml(java.lang.string)
使用UNESCAPEHTML,您可以做STH。喜欢:
String input = "A";
String unescaped = StringEscapeUtils.unescapeHtml(input);
boolean containsValidEscape = !input.equals(a);
不确定这是一个完美的解决方案,但是您可以使用apache commons lang:
try {
return StringEscapeUtils.unescapeHtml4(code).length() < code.length();
} catch (IllegalArgumentException e) {
return false;
}
这应该是您想要的方法:
public static boolean isValidHtmlEscapeCode(String string) {
String temp = "";
try {
temp = StringEscapeUtils.unescapeHtml3(string);
} catch (IllegalArgumentException e) {
return false;
}
return !string.equals(temp);
}
尝试使用正则表达式匹配:
public boolean isValidHtmlEscapeCode(String string) {
return string.matches("&;#([0-9]{1,4}|x[0-9a-fA-F]{1,4});");
}
或保存某些处理周期,您可以重复使用正则以进行多个比较:
Pattern pattern = Pattern.compile("&;#([0-9]{1,4}|x[0-9a-fA-F]{1,4});");
public boolean isValidHtmlEscapeCode(String string) {
return pattern.matches(string);
}
可以在rexlib.com