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JPA,Mysql Blob返回的数据太长

blob jpa hibernate java

50

onigunn · 技术社区 · 15 年前

byte[] 我的实体中的字段,例如:

@Entity
public class ServicePicture implements Serializable {
    private static final long serialVersionUID = 2877629751219730559L;
    // seam-gen attributes (you should probably edit these)
    @Id
    @GeneratedValue
    private Long id;
    private String description;

    @Lob
    @Basic(fetch = FetchType.LAZY)
    private byte[] picture;

在我的数据库架构中,字段设置为 BLOB 所以这应该没问题。不管怎样:每次我尝试插入图片或pdf时-没有比 1mb

16:52:27,327 WARN  [JDBCExceptionReporter] SQL Error: 0, SQLState: 22001
16:52:27,327 ERROR [JDBCExceptionReporter] Data truncation: Data too long for column 'picture' at row 1
16:52:27,328 ERROR [STDERR] javax.persistence.PersistenceException: org.hibernate.exception.DataException: could not insert: [de.ac.dmg.productfinder.entity.ServicePicture]
16:52:27,328 ERROR [STDERR]     at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629)
16:52:27,328 ERROR [STDERR]     at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:218)
16:52:27,328 ERROR [STDERR]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
16:52:27,328 ERROR [STDERR]     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
16:52:27,328 ERROR [STDERR]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
16:52:27,328 ERROR [STDERR]     at java.lang.reflect.Method.invoke(Unknown Source)
16:52:27,328 ERROR [STDERR]     at org.jboss.seam.persistence.EntityManagerInvocationHandler.invoke(EntityManagerInvocationHandler.java:46)
16:52:27,328 ERROR [STDERR]     at $Proxy142.persist(Unknown Source)

我已经检查了我的MySQL cnf和 max_allowed 参数设置为 16M

2 回复 | 直到 15 年前

1

124

Pascal Thivent 15 年前

这完全取决于用于 picture 列。根据您的需要,使用:

TINYBLOB
BLOB :最大长度为65535字节
MEDIUMBLOB
LONGBLOB :最大长度为4294967295字节

注意,如果从JPA注释生成表,那么可以通过指定 length 的属性 Column

@Lob @Basic(fetch = FetchType.LAZY)
@Column(length=100000)
private byte[] picture;

取决于 长度 ,您将得到:

       0 < length <=      255  -->  `TINYBLOB`
     255 < length <=    65535  -->  `BLOB`
   65535 < length <= 16777215  -->  `MEDIUMBLOB`
16777215 < length <=    2Â³Â¹-1  -->  `LONGBLOB`

2

Cyber 5 年前

我使用下面的图片,它的作品

@Lob
@Column(name = "file", columnDefinition = "LONGBLOB")
private byte[] file;

3

1

kory 10 年前

在本例中,我们必须使用以下语法:

public class CcpArchive
{
    ...
    private byte[] ccpImage;
    ...
    @Lob
    @Column(nullable = false, name = "CCP_IMAGE", columnDefinition="BINARY(500000)")
    public byte[] getCcpImage()
    {
        return ccpImage;
    }
    ...
}