Question

我有一个包含许多数据库实体的大型Java EE项目，并且JPA约束检查给我带来了很多麻烦！

首先，我有许多具有多种依赖关系的实体（OneToOne，OneToMany）。整个项目用于自动分析和计算OSS存储库中源代码的指标。（se.uom.gr/seagle）。

例如，有一个实体项目和一个实体Project_Timeline，用于保存历史分析信息。

这是Project实体类

public class Project implements Serializable {

private static final long serialVersionUID = 1L;

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


@Basic(optional = false)
@NotNull
@Size(min = 1, max = 255)
@Column(name = "name", unique = true)
private String name;

/**
 * A remote URL from where this project is cloned.
 * <p>
 */
@Size(max = 2048)
@Column(name = "remoteRepoPath", unique = true)
private String remoteRepoPath;

/**
 * The metrics that should be calculated on the next execution.
 * <p>
 */
@ManyToMany(mappedBy = "registeredProjects")
private Collection<Metric> registeredMetrics;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "project", orphanRemoval = true)
private Collection<Version> versions;


@OneToOne(cascade = CascadeType.ALL, mappedBy = "project")
private ProjectInfo projectInfo;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "project", orphanRemoval = true)
private Collection<ProjectTimeline> timeLines;


@OneToMany(cascade = CascadeType.ALL, mappedBy = "project", orphanRemoval = true)
private Collection<ProjectMetric> projectMetrics;

这是Project_TimeLine实体类

public class ProjectTimeline implements Serializable {

private static final long serialVersionUID = 1L;

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

@Column(name = "timestamp")
@Temporal(TemporalType.TIMESTAMP)
private Date timestamp;

@JoinColumn(name = "project_id", referencedColumnName = "id")
@ManyToOne(optional = false)
private Project project;

如果我正确理解了JPA指南，那么这些实体的正确创建是：

Project p = new Project();
project.setName("some-java-oss");
project.setURL("http:////bla bla bla");

ProjectTimeline pi = new ProjectTimeline();

pi.setProject(p);
p.setProjectTimeline(pi);

entityManager.persist(p);
entityManager.persist(pi);

所以我只对此，并期望JPA处理主键并成功加入。

BUT

JPA和Glassfish一直给我以下错误：

Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services -   2.5.2.v20140319-9ad6abd): 
org.eclipse.persistence.exceptions.DatabaseException
Internal Exception:    com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:     Column 'id' cannot be null
Error Code: 1048
Call: INSERT INTO project_timeline (id, timestamp, action_id, project_id) VALUES (?, ?, ?, ?)
  bind => [4 parameters bound]
Query: InsertObjectQuery(gr.uom.java.seagle.db.persistence.v2.ProjectTimeline[ id=null ])
 at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)

... 266 more

Caused by: 
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:     Column 'id' cannot be null

... 297 more

完整错误堆栈跟踪在这里：

http://java.uom.gr/~chaikalis/documents/full_error_stacktrace.txt

Java JPA GenerationType.TABLE无效

0 个答案: