java 检测字符串中文乱码

1.检测是否为乱码

public static boolean isMessyCode(String strName) {
Pattern p = Pattern.compile("\\s*|\t*|\r*|\n*");
Matcher m = p.matcher(strName);
String after = m.replaceAll("");
String temp = after.replaceAll("\\p{P}", "");
char[] ch = temp.trim().toCharArray();
float chLength = 0 ;
float count = 0;
for (int i = 0; i < ch.length; i++) {
char c = ch[i];
if (!Character.isLetterOrDigit(c)) {
if (!isChinese(c)) {
count = count + 1;
}
chLength++;
}
}
float result = count / chLength ;
if (result > 0.4) {
return true;
} else {
return false;
}
}

2.检查字符是否为中文

private static boolean isChinese(char c) {
Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
|| ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS
|| ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
|| ub == Character.UnicodeBlock.GENERAL_PUNCTUATION
|| ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {
return true;
}
return false;
}

3.中文转换编码

public static String toChinese(String msg){
if(isMessyCode(msg)){
try {
return new String(msg.getBytes("ISO8859-1"), "UTF-8");
} catch (Exception e) {
}
}
return msg ;
}

Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS ： 4E00-9FBF：CJK 统一表意符号

Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS ：F900-FAFF：CJK
兼容象形文字 Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
：3400-4DBF：CJK 统一表意符号扩展 A

CJK的意思是“Chinese，Japanese，Korea”的简写 ，实际上就是指中日韩三国的象形文字的Unicode编码

Character.UnicodeBlock.GENERAL_PUNCTUATION ：2000-206F：常用标点
Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION ：3000-303F：CJK 符号和标点
Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS ：FF00-FFEF：半角及全角形式

Character.isLetter(c)：判断字符是否是字母

Character.isDigit(c)：判断字符是否是数字