I have an old table that I'm working with, which looks like this:
+------------------+--------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+------------------+--------------+------+-----+---------+-------+
| BINARY_DATA_ID | varchar(255) | NO | PRI | | |
| BINARY_DATA | longblob | YES | | NULL | |
| BINARY_DATA_NAME | varchar(255) | YES | | NULL | |
+------------------+--------------+------+-----+---------+-------+
The main problem with this is that the BinaryData Java class loads the BINARY_DATA column, even if I only require the BINARY_DATA_NAME. I know that the best way to architect this is to split the data from the meta-data (like the file name) so they live in separate tables. From there it's trivial to make the data lazy-loaded. This is how it should have been done in the first place.
Unfortunately it may not be possible for me to do the above due to organizational constraints. As a workaround, is it possible to make that column lazy-loaded using some annotations instead of splitting things out into separate tables? I've modified the BinaryData class so that it has an inner static BinaryDataData class which is @Embedded and the attribute is @Basic(fetch=FetchType.LAZY):
@Entity
@Table
@Proxy(lazy=false)
@Inheritance(strategy=InheritanceType.JOINED)
public class BinaryData implements Serializable, Persistable<BinaryData>, Cloneable {
private static final long serialVersionUID = /** blah */;
@Id @Column @GeneratedValue(generator="uuid") @GenericGenerator(name="uuid", strategy="uuid")
private String id;
@Column
private String binaryDataName;
@Embedded
@Basic(fetch = FetchType.LAZY)
private BinaryDataData binaryData;
@Transient
private String cacheId;
/**
* Hibernate constructor
*/
public BinaryData() { /* Creates a new instance of Attachment. */}
public BinaryData(byte[] binaryData, String binaryDataName) {
this.binaryData = new BinaryDataData(ArrayUtils.clone(binaryData));
this.binaryDataName = binaryDataName;
}
/**
* Returns the BinaryData byte stream.
*
* @return binaryData byte stream
*/
@Embedded
@Basic(fetch = FetchType.LAZY)
public byte[] getBinaryData() {
if (this.binaryData == null) {
return new byte[0];
}
return binaryData.getActualData();
}
@Embeddable
public static class BinaryDataData implements Serializable {
@Column(length=32*1024*1024, columnDefinition="longblob", name="BINARY_DATA") @Lob
private byte[] actualData;
public BinaryDataData() { }
public BinaryDataData(byte[] data) {
this.actualData = data;
}
public byte[] getActualData() {
if (this.actualData == null) {
return new byte[0];
}
return this.actualData;
}
public void setBinaryData(byte[] newData) {
this.actualData = newData;
}
@Override public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof BinaryDataData)) {
return false;
}
final BinaryDataData other = (BinaryDataData) obj;
if (!Arrays.equals(actualData, other.actualData)) {
return false;
}
return true;
}
}
/** onwards... */
Unfortunately this doesn't work. The SQL that I'm seeing still shows a complete fetch of the object even if the binary data isn't requested:
select ideaattach0_.BINARY_DATA_ID as BINARY1_9_, ideaattach0_1_.BINARY_DATA as BINARY2_9_, ideaattach0_1_.BINARY_DATA_NAME as BINARY3_9_, ideaattach0_.IDEA_BUCKET_ID as IDEA2_136_ from IDEA_ATTACHMENT ideaattach0_ inner join BINARY_DATA ideaattach0_1_ on ideaattach0_.BINARY_DATA_ID=ideaattach0_1_.BINARY_DATA_ID where ideaattach0_.BINARY_DATA_ID=?
Any ideas? Thank you.
