Hibernate encodes wrong while persisting objects [UTF-8]

Question

I'm facing with UTF-8 encoding problem while persisting my model objects. In Turkish 'ı' is a letter. Also there're some other Turkish characters that is included in UTF-8 encoding. While I persist my model objects, all 'ı' characters are persisted as '?' to DB. I'm using MySQL 5.5 on Ubuntu Linux 64-bit OS. Also I've already set hibernate & c3p0 connection encoding property to UTF-8 too. When I debug, the data comes from client is true.

Here's my config and I'll be so happy if someone can help me.

Thanks in advance.

---

Spring & Hibernate Config

    <bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource"><ref local="dataSource"/></property>
        <property name="packagesToScan" value="com.tk.dms.model" />
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.use_sql_comments">true</prop>
                <prop key="hibernate.format_sql">false</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.generate_statistics">true</prop>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
                <prop key="hibernate.connection.characterEncoding">UTF-8</prop>
                <prop key="hibernate.connection.useUnicode">true</prop>
                <!-- c3p0 properties -->
                <prop key="hibernate.c3p0.min_size">2</prop>
                <prop key="hibernate.c3p0.max_size">50</prop>
                <prop key="hibernate.c3p0.maxPoolSize">50</prop>
                <prop key="hibernate.c3p0.minPoolSize">2</prop>
                <prop key="hibernate.c3p0.initialPoolSize">2</prop>
                <prop key="hibernate.c3p0.timeout">300</prop>
                <prop key="hibernate.c3p0.max_statements">50</prop>                
            </props>
        </property>
    </bean>

Answer 1

Try setting encoding in datasource

 <bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName">
        <value>com.mysql.jdbc.Driver</value>
    </property>
    <property name="url">
        <value>jdbc:mysql://127.0.0.1:3306/databaseName?characterEncoding=UTF-8</value>
    </property>
    <property name="username">
        <value>?</value>
    </property>
</bean>

Also are you sure that the input from forms is properly encoded? Do you use filter in your spring application? Run application in debug mode and check fields of your model object before persisting.

The filter should beplaced in your web.xml file:

<filter>
    <filter-name>SetCharacterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF8</param-value>
    </init-param>
    <init-param>
        <param-name>forceEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>SetCharacterEncodingFilter</filter-name>
    <url-pattern>*</url-pattern>
</filter-mapping>

Answer 2

If you have added the

?characterEncoding=UTF-8

parameter to the connection string consequently (after the db and tables have already been created), you need to recreate your database. Actually in my case i recreated my db with:

CREATE DATABASE dbname CHARACTER SET utf8 COLLATE utf8_general_ci;

OR

alter database my_database default charset utf8 collate utf8_general_ci;

Note that i was using cyrillic strings.