读取注解时出错播放框架2.2

Question

我已经开始学习 Play 框架，遵循 Java 指南（教程“ZenTasks”）。一切都很顺利，直到我发现这个错误：Error reading annotations for models.Task

类

package models;

import java.util.*;
import javax.persistence.*;
import play.db.ebean.*;

@Entity
public class Task extends Model {

    @Id
    public Long id;
    public String title;
    public boolean done = false;
    public Date dueDate;
    @ManyToOne
    public User assignedTo;
    public String folder;
    @ManyToOne
    public Project project;

    public static Model.Finder<Long,Task> find = new Model.Finder(Long.class, Task.class);


    public static List<Task> findTodoInvolving(String user) {
        return find.fetch("project").where()
                .eq("done", false)
                .eq("project.members.email", user)
                .findList();
    }

    public static Task create(Task task, Long project, String folder) {
        task.project = Project.find.ref(project);
        task.folder = folder;
        task.save();
        return task;
    }
}

错误信息

 @6hgmo097m - Internal server error, for (GET) [/] ->

play.api.UnexpectedException: Unexpected exception[RuntimeException: Error reading annotations for models.Task]
    at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(ApplicationProvider.scala:148) ~[play_2.10.jar:2.2.1]
    at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1$$anonfun$1.apply(ApplicationProvider.scala:112) ~[play_2.10.jar:2.2.1]
    at scala.Option.map(Option.scala:145) ~[scala-library.jar:na]
    at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1.apply(ApplicationProvider.scala:112) ~[play_2.10.jar:2.2.1]
    at play.core.ReloadableApplication$$anonfun$get$1$$anonfun$apply$1.apply(ApplicationProvider.scala:110) ~[play_2.10.jar:2.2.1]
    at scala.util.Success.flatMap(Try.scala:200) ~[scala-library.jar:na]
Caused by: java.lang.RuntimeException: Error reading annotations for models.Task
    at com.avaje.ebeaninternal.server.deploy.parse.ReadAnnotations.readAssociations(ReadAnnotations.java:54) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readDeployAssociations(BeanDescriptorManager.java:1048) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readEntityDeploymentAssociations(BeanDescriptorManager.java:547) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.deploy(BeanDescriptorManager.java:237) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.core.InternalConfiguration.<init>(InternalConfiguration.java:114) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.core.DefaultServerFactory.createServer(DefaultServerFactory.java:204) ~[avaje-ebeanorm.jar:na]
Caused by: java.lang.RuntimeException: Error with association to [class models.Project] from [models.Task.project]. Is class models.Project registered?
    at com.avaje.ebeaninternal.server.deploy.parse.AnnotationAssocOnes.readManyToOne(AnnotationAssocOnes.java:165) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.parse.AnnotationAssocOnes.readAssocOne(AnnotationAssocOnes.java:63) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.parse.AnnotationAssocOnes.parse(AnnotationAssocOnes.java:54) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.parse.ReadAnnotations.readAssociations(ReadAnnotations.java:45) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readDeployAssociations(BeanDescriptorManager.java:1048) ~[avaje-ebeanorm.jar:na]
    at com.avaje.ebeaninternal.server.deploy.BeanDescriptorManager.readEntityDeploymentAssociations(BeanDescriptorManager.java:547) ~[avaje-ebeanorm.jar:na]

Answer 1

有同样的错误，这（对我来说）是由于我的@ManyToOne 相关类没有用@Entity 注释标记（在你的情况下检查User 和Project）。还要确保这些类对Task 的引用包含@OneToMany 引用。