Spring DATA JPA + Hibernate-无法初始化代理-修复后无会话：

Question

Good day, all. I'm newbie in Spring Data + JPA. And i need your help. It's my first question on stackoverflow, that sorry if i formed my Question not correct.

I start to realise project using Spring Data + JPA + Hibernate, Spring MVC, Use MySQL.

I have DB scheme:

DB of project

DB scheme

application context:

<context:property-placeholder location="classpath:util.properties" />
<!--Activates various annotations to be detected in bean classes: Spring's @Required and @Autowired and so on-->
<context:annotation-config/>

<!-- Datasource.  -  MySQL -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClass}"/>
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}" />
</bean>

<!--Do not forget activate @Transactional JPA annotation with <annotation-driven/>-->
<!-- JPA Persistence Context and EntityManager configuration -->
<bean id="entityManagerFactory"
      class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" >
    <!--packagesToScan - search Entity and mapping them -->
    <property name="packagesToScan" value="by.GetItFree" />
    <property name="dataSource" ref="dataSource" />
    <property name="jpaVendorAdapter">
        <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" >
            <property name="generateDdl" value="true" />
            <property name="showSql" value="true" />
        </bean>
    </property>
    <property name="jpaProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.format_sql">false</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
            <prop key="hibernate.enable_lazy_load_no_trans">true</prop>
        </props>
    </property>
</bean>

<!-- Automatic Transaction Participation-->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<jpa:repositories base-package="by.GetItFree.orm.repository" entity-manager-factory-ref="entityManagerFactory"
                  transaction-manager-ref="transactionManager"/>

MVC Config:

<!--
    mvc:annotation-driven configures Spring MVC annotations
    Support for validating @Controller inputs with @Valid, if a JSR-303 Provider is present on the classpath.
    HttpMessageConverter support for @RequestBody method parameters and @ResponseBody method return values
    from @RequestMapping or @ExceptionHandler methods.
 -->
<mvc:annotation-driven/>

<!-- activate @Transactional JPA annotation -->
<tx:annotation-driven/>

<!-- ViewResolver bean config for mapping strings to jsp views -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <!-- Example: a logical view name of 'showMessage' is mapped to '/WEB-INF/jsp/showMessage.jsp' -->
    <property name="order" value="1" />
    <property name="prefix" value="/WEB-INF/view" />
    <property name="suffix" value=".jsp" />
</bean>


<mvc:view-controller path="/about.html" view-name="/about/about"/>
<mvc:view-controller path="/index.html" view-name="/index"/>


<!-- Static Resources Configuration (get access to static sources such as CSS and JavaScript files) -->
<mvc:resources mapping="/resources/**" location="/resources/" />

---

Some of JPA Persistence Entites:

Advert:

@Entity
public class Advert {
    private int id;
    private String karmaReq;
    private byte[] image;
    private int profileId;
    private String profileUsersUsername;
    private String head;
    private String content;
    private byte ordered;
    private Timestamp date;
    private Profile profile;
    private Collection<Comment> commentsById;

    @Id
    @Column(name = "id", nullable = false)
    public int getId() {
        return id;
    }

public void setId(int id) {
    this.id = id;
}

@Basic
@Column(name = "karmaReq", nullable = true, length = 45)
public String getKarmaReq() {
    return karmaReq;
}

public void setKarmaReq(String karmaReq) {
    this.karmaReq = karmaReq;
}

@Basic
@Column(name = "image", nullable = false)
public byte[] getImage() {
    return image;
}

public void setImage(byte[] image) {
    this.image = image;
}

@Basic
@Column(name = "profile_id", nullable = false)
public int getProfileId() {
    return profileId;
}

public void setProfileId(int profileId) {
    this.profileId = profileId;
}

@Basic
@Column(name = "profile_users_username", nullable = false, length = 45)
public String getProfileUsersUsername() {
    return profileUsersUsername;
}

public void setProfileUsersUsername(String profileUsersUsername) {
    this.profileUsersUsername = profileUsersUsername;
}

@Basic
@Column(name = "head", nullable = true, length = 45)
public String getHead() {
    return head;
}

public void setHead(String head) {
    this.head = head;
}

@Basic
@Column(name = "content", nullable = true, length = 450)
public String getContent() {
    return content;
}

public void setContent(String content) {
    this.content = content;
}

@Basic
@Column(name = "ordered", nullable = false)
public byte getOrdered() {
    return ordered;
}

public void setOrdered(byte ordered) {
    this.ordered = ordered;
}

@Basic
@Column(name = "date", nullable = false)
public Timestamp getDate() {
    return date;
}

public void setDate(Timestamp date) {
    this.date = date;
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Advert advert = (Advert) o;

    if (id != advert.id) return false;
    if (profileId != advert.profileId) return false;
    if (ordered != advert.ordered) return false;
    if (karmaReq != null ? !karmaReq.equals(advert.karmaReq) : advert.karmaReq != null) return false;
    if (!Arrays.equals(image, advert.image)) return false;
    if (profileUsersUsername != null ? !profileUsersUsername.equals(advert.profileUsersUsername) : advert.profileUsersUsername != null)
        return false;
    if (head != null ? !head.equals(advert.head) : advert.head != null) return false;
    if (content != null ? !content.equals(advert.content) : advert.content != null) return false;
    if (date != null ? !date.equals(advert.date) : advert.date != null) return false;

    return true;
}

@Override
public int hashCode() {
    int result = id;
    result = 31 * result + (karmaReq != null ? karmaReq.hashCode() : 0);
    result = 31 * result + Arrays.hashCode(image);
    result = 31 * result + profileId;
    result = 31 * result + (profileUsersUsername != null ? profileUsersUsername.hashCode() : 0);
    result = 31 * result + (head != null ? head.hashCode() : 0);
    result = 31 * result + (content != null ? content.hashCode() : 0);
    result = 31 * result + (int) ordered;
    result = 31 * result + (date != null ? date.hashCode() : 0);
    return result;
}

@ManyToOne
@JoinColumns({@JoinColumn(name = "profile_id", referencedColumnName = "id", nullable = false, insertable = false, updatable = false), @JoinColumn(name = "profile_users_username", referencedColumnName = "users_username", nullable = false, insertable = false, updatable = false)})
public Profile getProfile() {
    return profile;
}

public void setProfile(Profile profile) {
    this.profile = profile;
}

@OneToMany(mappedBy = "advertByAdvertId")
public Collection<Comment> getCommentsById() {
    return commentsById;
}

public void setCommentsById(Collection<Comment> commentsById) {
    this.commentsById = commentsById;
}

@Override
public String toString() {
    return "Advert{" +
            "id=" + id +
            ", karmaReq='" + karmaReq + '\'' +
            ", image=" + Arrays.toString(image) +
            ", profileId=" + profileId +
            ", profileUsersUsername='" + profileUsersUsername + '\'' +
            ", head='" + head + '\'' +
            ", content='" + content + '\'' +
            ", ordered=" + ordered +
            ", date=" + date +
            ", profile=" + profile +
            ", commentsById=" + commentsById +
            '}';
}

}

// I know , that if i comment call profile in to String(), all will be work.

Profile

@Entity
@IdClass(ProfilePK.class)
public class Profile {
    private int id;
    private String usersUsername;
    private Integer karma;
    private String phone;
    private byte[] icon;
    private Collection<Advert> adverts;
    private Collection<Comment> comments;
    private Collection<Message> messages;
    private Users usersByUsersUsername;
@Id
@Column(name = "id", nullable = false)
public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

@Id
@Column(name = "users_username", nullable = false, length = 45)
public String getUsersUsername() {
    return usersUsername;
}

public void setUsersUsername(String usersUsername) {
    this.usersUsername = usersUsername;
}

@Basic
@Column(name = "karma", nullable = true)
public Integer getKarma() {
    return karma;
}

public void setKarma(Integer karma) {
    this.karma = karma;
}

@Basic
@Column(name = "phone", nullable = true, length = 15)
public String getPhone() {
    return phone;
}

public void setPhone(String phone) {
    this.phone = phone;
}

@Basic
@Column(name = "icon", nullable = true)
public byte[] getIcon() {
    return icon;
}

public void setIcon(byte[] icon) {
    this.icon = icon;
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Profile profile = (Profile) o;

    if (id != profile.id) return false;
    if (usersUsername != null ? !usersUsername.equals(profile.usersUsername) : profile.usersUsername != null)
        return false;
    if (karma != null ? !karma.equals(profile.karma) : profile.karma != null) return false;
    if (phone != null ? !phone.equals(profile.phone) : profile.phone != null) return false;
    if (!Arrays.equals(icon, profile.icon)) return false;

    return true;
}

@Override
public int hashCode() {
    int result = id;
    result = 31 * result + (usersUsername != null ? usersUsername.hashCode() : 0);
    result = 31 * result + (karma != null ? karma.hashCode() : 0);
    result = 31 * result + (phone != null ? phone.hashCode() : 0);
    result = 31 * result + Arrays.hashCode(icon);
    return result;
}

@OneToMany(mappedBy = "profile")
public Collection<Advert> getAdverts() {
    return adverts;
}

public void setAdverts(Collection<Advert> adverts) {
    this.adverts = adverts;
}

@OneToMany(mappedBy = "profile")
public Collection<Comment> getComments() {
    return comments;
}

public void setComments(Collection<Comment> comments) {
    this.comments = comments;
}

@OneToMany(mappedBy = "profile")
public Collection<Message> getMessages() {
    return messages;
}

public void setMessages(Collection<Message> messages) {
    this.messages = messages;
}

@ManyToOne
@JoinColumn(name = "users_username", referencedColumnName = "username", nullable = false, insertable = false, updatable = false)
public Users getUsersByUsersUsername() {
    return usersByUsersUsername;
}

public void setUsersByUsersUsername(Users usersByUsersUsername) {
    this.usersByUsersUsername = usersByUsersUsername;
}

@Override
public String toString() {
    return "Profile{" +
            "id=" + id +
            ", usersUsername='" + usersUsername + '\'' +
            ", karma=" + karma +
            ", phone='" + phone + '\'' +
            ", icon=" + Arrays.toString(icon) +
            ", adverts=" + adverts +
            ", comments=" + comments +
            ", messages=" + messages +
            ", usersByUsersUsername=" + usersByUsersUsername +
            '}';
}

}

ORM

AdvertDAO

   /**
 * DAO interface responsible for operation with Advertising.
 * <p>
 * Created by Novik Igor on 09.02.2017.
 */
public interface AdvertDAO {

    /**
     * Method returned list of Advert's from the DB.
     *
     * @return list of Advertising's.
     */
    List<Advert> findAll();

    /**
     * Method returned list of Advert from the DB according ID.
     *
     * @param head id of the Advert;
     * @return Advertising according id.
     */
    Advert findByHead(String head);
}

AdvertDAORepository

/**
 * SpringData AdvertDAO repository.
 *
 * Created by Novik Igor on 10.02.2017.
 */
public interface AdvertDAORepository extends CrudRepository<Advert,Integer> {

    List<Advert> findByHead(String head);

}

Service for Spring Data/JPA - AdvertDAOImpl

/**
 * Repository bean that implements JPA DAO Advert interfaces responsible for operation with Advertising from DB.
 * <p>
 * Created by nolik on 10.02.17.
 */

@Service("jpaAdvertDAO")
@Repository
@Transactional
public class AdvertDAOImpl implements AdvertDAO {

    @Autowired
    private AdvertDAORepository advertDAORepository;

    @Override
    public List<Advert> findAll() {

        return Lists.newArrayList(advertDAORepository.findAll());
    }

    @Override
    public Advert findByHead(String head) {

        return (Advert) advertDAORepository.findByHead(head);
    }
}

Test MVC Controller:

    @Controller
public class TestController {

    @Autowired
    AdvertDAO jpaAdvertDAO;
    @Autowired
    CommentDAO jpaCommentDAO;

    @RequestMapping(value = "/testCall", method = RequestMethod.GET)
    public ModelAndView readCookieExample() {

        System.out.println(" Test console");
        return new ModelAndView("/error/errorpage");

    }

    @RequestMapping(value = "/jpaFindAllAdvert", method = RequestMethod.GET)
    public ModelAndView jpaFindAllAdvert() {
        System.out.println("ORMController ormFindAllUsers is called");
        List<Advert> adverts = jpaAdvertDAO.findAll();
        return new ModelAndView("/error/test", "resultObject", adverts);

    }

    @RequestMapping(value = "/jpaFindAllComments", method = RequestMethod.GET)
    public ModelAndView jpaFindAllComments() {
        System.out.println("ORMController FindAllComments is called");
        List<Comment> comments = jpaCommentDAO.findAll();
        return new ModelAndView("/error/test", "resultObject", comments);

    }
}

Simple JSP for showing result of calling "/jpaFindAllAdvert"

 <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Test</title> </head> <body> <%--<a href="${adverts}" class="list-group-item">Find All Adverts</a>--%> ${resultObject} </body> </html> 

Firstly i faced with the next exception:

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: by.GetItFree.entities.Profile.adverts, could not initialize proxy - no Session
org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:563)
org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:205)
org.hibernate.collection.internal.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:542)
org.hibernate.collection.internal.AbstractPersistentCollection.read(AbstractPersistentCollection.java:133)
org.hibernate.collection.internal.PersistentBag.toString(PersistentBag.java:509)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Profile.toString(Profile.java:144)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Advert.toString(Advert.java:174)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
java.util.AbstractCollection.toString(AbstractCollection.java:462)
org.apache.el.lang.ELSupport.coerceToString(ELSupport.java:497)
org.apache.el.lang.ELSupport.coerceToType(ELSupport.java:529)
org.apache.el.ExpressionFactoryImpl.coerceToType(ExpressionFactoryImpl.java:47)
javax.el.ELContext.convertToType(ELContext.java:304)
org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:944)
org.apache.jsp.WEB_002dINF.view.error.test_jsp._jspService(test_jsp.java:118)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1271)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1037)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:980)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)

I google that it's a result of N+1 SQL problem for Hibernate for Leazy initialisation of Joined with @ManyToONe relations.

I use way to fix with adding: <prop key="hibernate.enable_lazy_load_no_trans">true</prop> to "Jpa Properties"

After this i faced with: StackOverflow exeption:

java.lang.StackOverflowError
java.util.AbstractCollection.toString(AbstractCollection.java:454)
org.hibernate.collection.internal.PersistentBag.toString(PersistentBag.java:510)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Profile.toString(Profile.java:144)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Advert.toString(Advert.java:174)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
java.util.AbstractCollection.toString(AbstractCollection.java:462)
org.hibernate.collection.internal.PersistentBag.toString(PersistentBag.java:510)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Profile.toString(Profile.java:144)
java.lang.String.valueOf(String.java:2994)
java.lang.StringBuilder.append(StringBuilder.java:131)
by.GetItFree.entities.Advert.toString(Advert.java:174)

Etc.. - very long listing

In Tocat Log in the last case - i see big listing JPQL/or HSQL i'm not shure:

  RMController ormFindAllUsers is called
Hibernate: select advert0_.id as id1_1_, advert0_.content as content2_1_, advert0_.date as date3_1_, advert0_.head as head4_1_, advert0_.image as image5_1_, advert0_.karmaReq as karmaReq6_1_, advert0_.ordered as ordered7_1_, advert0_.profile_users_username as profile_9_1_, advert0_.profile_id as profile_8_1_ from Advert advert0_
Hibernate: select profile0_.users_username as users_us1_5_0_, profile0_.id as id2_5_0_, profile0_.icon as icon3_5_0_, profile0_.karma as karma4_5_0_, profile0_.phone as phone5_5_0_, users1_.username as username1_6_1_, users1_.enabled as enabled2_6_1_, users1_.password as password3_6_1_ from Profile profile0_ inner join Users users1_ on profile0_.users_username=users1_.username where profile0_.users_username=? and profile0_.id=?
Hibernate: select adverts0_.profile_users_username as profile_9_1_0_, adverts0_.profile_id as profile_8_1_0_, adverts0_.id as id1_1_0_, adverts0_.id as id1_1_1_, adverts0_.content as content2_1_1_, adverts0_.date as date3_1_1_, adverts0_.head as head4_1_1_, adverts0_.image as image5_1_1_, adverts0_.karmaReq as karmaReq6_1_1_, adverts0_.ordered as ordered7_1_1_, adverts0_.profile_users_username as profile_9_1_1_, adverts0_.profile_id as profile_8_1_1_ from Advert adverts0_ where adverts0_.profile_users_username=? and adverts0_.profile_id=?
Hibernate: select profile0_.users_username as users_us1_5_0_, profile0_.id as id2_5_0_, profile0_.icon as icon3_5_0_, profile0_.karma as karma4_5_0_, profile0_.phone as phone5_5_0_, users1_.username as username1_6_1_, users1_.enabled as enabled2_6_1_, users1_.password as password3_6_1_ from Profile profile0_ inner join Users users1_ on profile0_.users_username=users1_.username where profile0_.users_username=? and profile0_.id=?

My progect on github: ProgectSourceCode

What's the reason of this behaiviour. And what's the solution? Thx for your attention and support.

Answer 1

The reason you're having this problem is because associations that your view requires should be initialized inside a transaction boundary to avoid the LazyInitializationException . Adding an option to load collections outside of a transaction is merely a bandaid and doesn't truly address the underlying design flaw of your code.

If your view requires that you load Profile and its associated collection of Advert entities, then your either your data access should should specifically toggle that behavior or the query specify that you need that collection initialized.

There are a number of ways you can trigger this collection to be loaded as part of a query.

• JPQL/HQL using a JOIN FETCH on the adverts collection.
• Specify a join fetch using the Criteria API
• Use @FetchProfile to toggle a specific fetch strategy by name.
• Use @NamedEntityGraph .