MySQL stored procedure with UTF-8 parameters and a JDBC client

hello.sql

CREATE PROCEDURE hello(str varchar(20) character set utf8)
BEGIN
    select concat('Hello ', str);
END

Test.java

import java.sql.*;
class Test {
    public static void main(String [] args) throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection(
                "jdbc:mysql://localhost/test?characterEncoding=utf8", "user", "pass");
        Statement s = conn.createStatement();
        s.execute("call hello('겠겠지만');");
        ResultSet rs = s.getResultSet();
        rs.next();
        System.out.println(rs.getString(1));
        s.close();
        conn.close();
    }
}

Great, really helped. I am using org.springframework.jdbc.core classes rather than java.sql - must be the version of the driver spring is using...