Question

我有两个项目，一个是Maven依赖的，另一个是。两者都有独立的PostgreSQL数据库。如果我运行该应用程序，则当我尝试在被依赖项目中使用被依赖项目的实体时，将引发“不是实体”错误。

我已经尝试将事务类型设置为JTA或RESSOURCE-LOCAL或根本不设置。我还使用Eclipse JPA工具从废料中再次生成了实体。

User.java：

/**
 * The persistent class for the "Users" database table.
 * 
 */
@Entity
@Table(name = "\"Users\"")
@NamedQuery(name = "User.findAll", query = "SELECT u FROM User u")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.TABLE)
    private Integer id;

    private String mail;

    private String password;

    // bi-directional many-to-many association to Role
    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "\"User_Role\"", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = {
            @JoinColumn(name = "role_id") })
    private Set<Role> roles;

    // bi-directional many-to-many association to Permission
    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "\"User_Permission\"", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = {
            @JoinColumn(name = "permission_id") })
    private Set<Permission> permissions;

    public User() {
    }

    public Integer getId() {
        return this.id;
    }

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

    public String getMail() {
        return this.mail;
    }

    public void setMail(String mail) {
        this.mail = mail;
    }

    public String getPassword() {
        return this.password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Set<Permission> getPermissions() {
        return this.permissions;
    }

    public void setPermissions(Set<Permission> permissions) {
        this.permissions = permissions;
    }

    public Set<Role> getRoles() {
        return this.roles;
    }

    public void setRoles(Set<Role> roles) {
        this.roles = roles;
    }
}

persistence.xml：

    <persistence-unit name="Authentication" transaction-type="JTA">
        <class>com.auticon.learning.authentication.entities.User</class>
        <class>com.auticon.learning.authentication.entities.Permission</class>
        <class>com.auticon.learning.authentication.entities.Role</class>

        <properties>
        <!-- EclipseLink should create the database schema automatically -->
            <property name="eclipselink.ddl-generation" value="create-tables" />
            <property name="eclipselink.ddl-generation.output-mode"
                value="database" />
            <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"></property>
            <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/Credentials"></property>
            <property name="javax.persistence.jdbc.user" value="postgres"></property>
            <property name="javax.persistence.jdbc.password" value="******"></property>
        </properties>
    </persistence-unit>

引发错误的类：

    public static User findUser(String username) {
        CriteriaBuilder builder = SessionConfig.getSession().getCriteriaBuilder();
        CriteriaQuery<User> criteriaQuery = builder.createQuery(User.class);

//Error is thrown when I try to get the Root Parameter of the Entity
        Root<User> root = criteriaQuery.from(User.class);

        criteriaQuery.where(builder.equal(root.get(User_.MAIL), username));
        Query<User> query = SessionConfig.getSession().createQuery(criteriaQuery);

        try {
            return query.getSingleResult();
        } catch (NoResultException e) {
            return null;
        }
    }

其他项目中的调用类，这取决于以上项目（是从Primefaces Showcase：P中获得的大部分内容）：

    public void login() {
        FacesMessage message = null;
        boolean loggedIn = false;

//Login.checkPW() first action is calling findUser()
        if (Login.checkPW(username, password)) {
            loggedIn = true;
            message = new FacesMessage(FacesMessage.SEVERITY_INFO, "Welcome", username);
        } else {
            loggedIn = false;
            message = new FacesMessage(FacesMessage.SEVERITY_WARN, "Loggin Error", "Invalid credentials");
        }

        FacesContext.getCurrentInstance().addMessage(null, message);
        PrimeFaces.current().ajax().addCallbackParam("loggedIn", loggedIn);
    }

Screen of the PostgreSQL DB （我不允许直接在帖子中发布图片）

JPA意识到我已经正确标注了Entity，并在persitence.xml中列出了该实体，并且该表确实存在于数据库中。

完成Stacktrace：

原因：java.lang.IllegalArgumentException：不是实体：com.auticon.learning.authentication.entities.User类在org.hibernate.metamodel.internal.MetamodelImpl.entity（MetamodelImpl.java:536）在org.hibernate.query.criteria.internal.QueryStructure.from（QueryStructure.java:126）在org.hibernate.query.criteria.internal.CriteriaQueryImpl.from（CriteriaQueryImpl.java:153）在com.auticon.learning.authentication.client.DBOperations.findUser（DBOperations.java:22）在com.auticon.learning.authentication.api.Login.checkPW（Login.java:9）在de.auticon.views.UserLoginView.login（UserLoginView.java:43）在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处在sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.lang.reflect.Method.invoke（Method.java:498）在com.sun.el.util.ReflectionUtil.invokeMethod（ReflectionUtil.java:181）在com.sun.el.parser.AstValue.invoke（AstValue.java:289）在com.sun.el.MethodExpressionImpl.invoke（MethodExpressionImpl.java:304）在org.jboss.weld.module.web.util.el.ForwardingMethodExpression.invoke（ForwardingMethodExpression.java:40）在org.jboss.weld.module.web.el.WeldMethodExpression.invoke（WeldMethodExpression.java:50）在org.jboss.weld.module.web.util.el.ForwardingMethodExpression.invoke（ForwardingMethodExpression.java:40）在org.jboss.weld.module.web.el.WeldMethodExpression.invoke（WeldMethodExpression.java:50）在com.sun.faces.facelets.el.TagMethodExpression.invoke（TagMethodExpression.java:65）在com.sun.faces.application.MethodBindingMethodExpressionAdapter.invoke（MethodBindingMethodExpressionAdapter.java:66） ... 58更多

Answer 1

亲爱的，请检查配置文件（hibernate.xml或persistence.xml）中Entity bean的条目。实际上，我们的持久性上下文是基于我们的配置文件构建的，因此，如果未在其中注册您的实体文件，则该框架不会将其视为实体Bean /类。

错误：不是实体。但是@Entity和persistence.xml正确

1 个答案: