Special characters with JPA, JDBC, and mysql - jpa

Question

I use JPA, JDBC and MySQL for my Spring Boot project. I have some trouble with special characters.
If I write an SQL query via JdbcTemplate, it's just fine. I can get back "á" characters.
But if it's via JPA, those characters are �-s.
The schema's default collation is utf8_hungarian_ci, and the default characterset is utf8.
My application.properties:
spring.jpa.database: MYSQL
spring.jpa.hibernate.ddl-auto: update
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url: jdbc:mysql://localhost:3306/databasename?useUnicode=yes&characterEncoding=UTF-8
spring.datasource.username: root
spring.datasource.password: password
I have two tables, user and userroles, and they are connected with #ManyToMany relations with a jointable.
User.java:
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(
name = "user_userrole",
joinColumns = #JoinColumn(name = "user_id", referencedColumnName = "id"),
inverseJoinColumns = #JoinColumn(name = "userrole_id", referencedColumnName = "id"))
private List<UserRole> userRoles;
public List<UserRole> getUserRoles() {
return userRoles;
}
UserRole.java:
#ManyToMany(mappedBy = "userRoles")
private List<User> users;
When I call this method:
currentUser.getUserRoles();
all "á" characters are replaced by �-s.
What am I missing?
EDIT:
I added a new user: árvíztűrő tükörfúrógép to the database. (I could do it without any problem, and I save user with jpa too, by the way.)
But when I tried to log in, I've got this exception:
error":"Internal Server Error","exception":"java.io.CharConversionException"
,"message":"Not an ISO 8859-1 character: ű"
pom.xml:
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
</properties>

Answer 1

<property name="hibernate.connection.useUnicode" value="true" />
<property name="hibernate.connection.characterEncoding" value="UTF-8" />
with hibernate 4.3.1 this works:
<property name="connection.useUnicode">true</property>
<property name="connection.characterEncoding">utf-8</property>

Answer 2

Please add below in web xml
<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>