Hibernate获取数据java.lang.StackOverflowError

原因：因为在重写toString()方法时，把关联的属性也放入到toString方法中了，去掉就可以了

@Entity
@Table(name = "test.stu")
@Data
@NoArgsConstructor
public class Student {

	@Id
	@Column(name = "id")
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Integer number;
	private String name;
	private Integer age;
	private Integer classid;
	@ManyToOne(fetch = FetchType.EAGER)
	@JoinColumn(name = "classid" , referencedColumnName = "classid", insertable = false, updatable = false)
	private Clazz clazz;
	
}

在clazz类中的toString方法中去掉stu属性

@Entity
@Table(name = "test.cla")
@Data
@NoArgsConstructor
@ToString(exclude = "stu")
public class Clazz implements Serializable {

	private static final long serialVersionUID = 5451999649657651654L;
	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private Integer id;
	private String name;
	private Integer classid;
	@OneToMany(fetch=FetchType.EAGER, cascade=CascadeType.ALL)
	@JoinColumn(name = "classid", referencedColumnName = "classid")
	private List<Student> stu;
	
}