mysql表utf-8 字符串入库编码异常

分析：http://www.myexception.cn/mysql/639943.html

解决方法：http://blog.sina.com.cn/s/blog_3f78232201011o26.html

public class Utf8Filter {
 
public static void main(String[] args) throws Exception {
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0x41 }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0xf3, (byte) 0xb7,
 
(byte) 0xa2, (byte) 0xbe }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0x41, (byte) 0xf3,
 
(byte) 0xb7, (byte) 0xa2, (byte) 0xbe }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0xf3, (byte) 0xb7,
 
(byte) 0xa2, (byte) 0xbe, (byte) 0x41 }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0x41, (byte) 0xf3,
 
(byte) 0xb7, (byte) 0xa2, (byte) 0xbe, (byte) 0x41 }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0xf3, (byte) 0xb7,
 
(byte) 0xa2, (byte) 0xbe, (byte) 0xf3, (byte) 0xb7, (byte) 0xa2, (byte) 0xbe,
 
(byte) 0x41 }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0x41, (byte) 0xf3,
 
(byte) 0xb7, (byte) 0xa2, (byte) 0xbe, (byte) 0xf3, (byte) 0xb7, (byte) 0xa2,
 
(byte) 0xbe }, "utf-8")));
 
System.out.println(filterMt4BytesUtf8(new String(new byte[] { (byte) 0x41, (byte) 0xf3,
 
(byte) 0xb7, (byte) 0xa2, (byte) 0xbe, (byte) 0xf3, (byte) 0xb7, (byte) 0xa2,
 
(byte) 0xbe, (byte) 0x41 }, "utf-8")));
 
}
 
private static String filterMt4BytesUtf8(String input) {
 
if (StringUtils.isBlank(input))
 
return input;
 
ByteArrayOutputStream is = new ByteArrayOutputStream();
 
byte[] bytes = input.getBytes();
 
outter: for (int i = 0, length = bytes.length; i < length; i++) {
 
byte b = bytes[i];
 
while (((b & 0xF8) == 0xF0) || ((b & 0xFc) == 0xF8) || ((b & 0xFe) == 0xFc)) {
 
// found a byte of 4, 5, 6 UTF-8 bytes for a character
 
// eat the following bytes of this character
 
while (++i < length && ((b = bytes[i]) & 0xC0) == 0x80)
 
;
 
// insert a replacement character
 
is.write((byte) 0xEF);
 
is.write((byte) 0xBF);
 
is.write((byte) 0xBD);
 
if (i >= length) {
 
// we reach the end of byte array
 
break outter;
 
}
 
}
 
// found byte of 1, 2, 3 UTF-8 bytes for a character
 
is.write(b);
 
}
 
try {
 
return new String(is.toByteArray(), "utf-8");
 
} catch (UnsupportedEncodingException e) {
 
logger.error("filter more than 4 bytes utf-8 character failed!", e);
 
}
 
return input;
 
}
 
}