Checking UTF-8 data type 3-byte, or 4-byte Unicode
character-encoding, java, mysql, unicode, utf-8
Solution
UTF-8 encodes everything in the basic multilingual plane (i.e. U+0000 to U+FFFF inclusive) in 1-3 bytes. Therefore, you just need to check whether everything in your string is in the BMP.
In Java, that means checking whether any `char` (which is a UTF-16 code unit) is a high or low surrogate character, as Java will use surrogate pairs to encode non-BMP characters:
public static boolean isEntirelyInBasicMultilingualPlane(String text) {
for (int i = 0; i < text.length(); i++) {
if (Character.isSurrogate(text.charAt(i))) {
return false;
}
}
return true;
}
Problem
In my database I get the error ``` com.mysql.jdbc.MysqlDataTruncation: Data truncation: Data too long for column ``` I use Java and MySQL 5. As I know 4-byte Unicode is legal i Java, but illegal in MySQL 5, I think that it can cause my problem and I want to check type of my data, so here's my question: How can i check that my UTF-8 data is 3-byte or 4-byte Unicode?