JAVA实现过滤掉文本中的表情

比如我们要把微信昵称存入数据库，就需要把表情给过滤掉。

package com.zjr.common.utils;

import org.apache.commons.lang3.StringUtils;

public class EmojiFilter {

/**
* 检测是否有emoji字符
*
* @param source
* @return 一旦含有就抛出
*/
public static boolean containsEmoji(String source) {
if (StringUtils.isBlank(source)) {
return false;
}

int len = source.length();

for (int i = 0; i < len; i++) {
char codePoint = source.charAt(i);

if (isEmojiCharacter(codePoint)) {
// do nothing，判断到了这里表明，确认有表情字符
return true;
}
}

return false;
}

private static boolean isEmojiCharacter(char codePoint) {
return (codePoint == 0x0) || (codePoint == 0x9) || (codePoint == 0xA) || (codePoint == 0xD) || ((codePoint >= 0x20) && (codePoint <= 0xD7FF))
|| ((codePoint >= 0xE000) && (codePoint <= 0xFFFD)) || ((codePoint >= 0x10000) && (codePoint <= 0x10FFFF));
}

/**
* 过滤emoji 或者 其他非文字类型的字符
*
* @param source
* @return
*/
public static String filterEmoji(String source) {

if (!containsEmoji(source)) {
return source;// 如果不包含，直接返回
}
// 到这里铁定包含
StringBuilder buf = null;

int len = source.length();

for (int i = 0; i < len; i++) {
char codePoint = source.charAt(i);

if (isEmojiCharacter(codePoint)) {
if (buf == null) {
buf = new StringBuilder(source.length());
}

buf.append(codePoint);
}
}

if (buf == null) {
return source;// 如果没有找到 emoji表情，则返回源字符串
} else {
if (buf.length() == len) {// 这里的意义在于尽可能少的toString，因为会重新生成字符串
buf = null;
return source;
} else {
return buf.toString();
}
}
}
}