[java] java.sql.SQLException: Incorrect string value: '\xF0\x9F\x91\xBD\xF0\x9F...'

I have the following string value: "walmart obama "

I am using MySQL and Java.

I am getting the following exception: `java.sql.SQLException: Incorrect string value: '\xF0\x9F\x91\xBD\xF0\x9F...'

Here is the variable I am trying to insert into:

var1 varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL`

My Java code that is trying to insert "walmart obama " is a preparedStatement. So I am using the setString() method.

It looks like the problem is the encoding of the values . How can I fix this? Previously I was using Derby SQL and the values just ended up being two sqaures (I think this is the representation of the null character)

All help is greatly appreciated!

All in all, to save symbols that require 4 bytes you need to update characher-set and collation for utf8mb4:

1. database table/column: alter table <some_table> convert to character set utf8mb4 collate utf8mb4_unicode_ci
2. database server connection (see)

On my development enviromnt for #2 I prefer to set parameters on command line when starting the server: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci

btw, pay attention to Connector/J behavior with SET NAMES 'utf8mb4':

Do not issue the query set names with Connector/J, as the driver will not detect that the character set has changed, and will continue to use the character set detected during the initial connection setup.

And avoid setting characterEncoding parameter in connection url as it will override configured server encoding:

To override the automatically detected encoding on the client side, use the characterEncoding property in the URL used to connect to the server.

What you have is EXTRATERRESTRIAL ALIEN (U+1F47D) and BROKEN HEART (U+1F494) which are not in the basic multilingual plane. They cannot be even represented in java as one char, "".length() == 4. They are definitely not null characters and one will see squares if you are not using fonts that support them.

MySQL's utf8 only supports basic multilingual plane, and you need to use utf8mb4 instead:

For a supplementary character, utf8 cannot store the character at all, while utf8mb4 requires four bytes to store it. Since utf8 cannot store the character at all, you do not have any supplementary characters in utf8 columns and you need not worry about converting characters or losing data when upgrading utf8 data from older versions of MySQL.

So to support these characters, your MySQL needs to be 5.5+ and you need to use utf8mb4 everywhere. Connection encoding needs to be utf8mb4, character set needs to be utf8mb4 and collaction needs to be utf8mb4. For java it's still just "utf-8", but MySQL needs a distinction.

I don't know what driver you are using but a driver agnostic way to set connection charset is to send the query:

SET NAMES 'utf8mb4'

Right after making the connection.

See also this for Connector/J:

14.14: How can I use 4-byte UTF8, utf8mb4 with Connector/J?

To use 4-byte UTF8 with Connector/J configure the MySQL server with character_set_server=utf8mb4. Connector/J will then use that setting as long as characterEncoding has not been set in the connection string. This is equivalent to autodetection of the character set.

Adjust your columns and database as well:

var1 varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NOT NULL

Again, your MySQL version needs to be relatively up-to-date for utf8mb4 support.

I guess MySQL doesn't believe this to be valid UTF8 text. I tried an insert on a test table with the same column definition (mysql client connection was also UTF8) and although it did the insert, the data I retrieved with the MySQL CLI client as well as JDBC didn't retrieve the values correctly. To be sure UTF8 did work correctly, I inserted an "ö" instead of an "o" for obama:

johan@maiden:~$ mysql -vvv test < insert.sql 
--------------
insert into utf8_test values(_utf8 "walmart öbama ")
--------------

Query OK, 1 row affected, 1 warning (0.12 sec)

johan@maiden:~$ file insert.sql 
insert.sql: UTF-8 Unicode text

Small java application to test with:

package test.sql;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class Test
{

    public static void main(String[] args)
    {
        System.out.println("test string=" + "walmart öbama ");
        String url = "jdbc:mysql://hostname/test?useUnicode=true&characterEncoding=UTF-8";
        try
        {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            Connection c = DriverManager.getConnection(url, "username", "password");
            PreparedStatement p = c.prepareStatement("select * from utf8_test");
            p.execute();
            ResultSet rs = p.getResultSet();
            while (!rs.isLast())
            {
                rs.next();
                String retrieved = rs.getString(1);
                System.out.println("retrieved=\"" + retrieved + "\"");

            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

}

Output:

johan@appel:~/workspaces/java/javatest/bin$ java test.sql.Test
test string=walmart öbama 
retrieved="walmart öbama "

Also, I've tried the same insert with the JDBC connection and it threw the same exception you are getting. I believe this to be a MySQL bug. Maybe there's a bug report about such a situation already..

I had kind of the same problem and after going carefully against all charsets and finding that they were all right, I realized that the bugged property I had in my class was annotated as @Column instead of @JoinColumn (javax.presistence; hibernate) and it was breaking everything up.

Append the line useUnicode=true&characterEncoding=UTF-8 to your jdbc url.

In your case the data is not being send using UTF-8 encoding.

I faced the same issue and solved it by setting the Collation to utf8_general_ci for each column.

How I solved my problem.

I had

?useUnicode=true&characterEncoding=UTF-8

In my hibernate jdbc connection url and I changed the string datatype to longtext in database, which was varchar before.

Weirdly, I found that REMOVING &characterEncoding=UTF-8 from the JDBC url did the trick for me with similar issues.

Based on my properties,

jdbc_url=jdbc:mysql://localhost:3306/dbName?useUnicode=true

I think this supports what @Esailija has said above, i.e. my MySQL, which is indeed 5.5, is figuring out its own favorite flavor of UTF-8 encoding.

(Note, I'm also specifying the InputStream I'm reading from as UTF-8 in the java code, which probably doesn't hurt)...

execute

show VARIABLES like "%char%”;

find character-set-server if is not utf8mb4.

set it in your my.cnf, like

vim /etc/my.cnf

add one line

character_set_server = utf8mb4

at last restart mysql

Besides,data type can use blob install of varchar or text.

This setting useOldUTF8Behavior=true worked fine for me. It gave no incorrect string errors but it converted special characters like à into multiple characters and saved in the database.

To avoid such situations, I removed this property from the JDBC parameter and instead converted the datatype of my column to BLOB. This worked perfect.