EclipseLink Basic FetchType.LAZY configuration - jpa

Question

I'm having some trouble getting an attribute on an entity to lazy load. I've scoured the EclipseLink documentation but can't figure out what I'm doing wrong.
Basically, I have a table with some columns, one of which is a file, the size of which can be very large. I'd like to have the file itself lazy load, so that when I load all the rows of the table I don't have to wait for the file to load into memory if it won't be used.
The setup:
EclipseLink 2.6.2
ReportHistoryFile:
#Entity
#Table(name = "REPORT_HISTORY_FILES")
#NamedQueries({
#NamedQuery(name = "ReportHistoryFile.findAll", query = "SELECT p FROM ReportHistoryFile p order by p.createDate DESC")})
public class ReportHistoryFile implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#SequenceGenerator(name = "SEQ_REPORTHISTORYFILE_GEN", sequenceName = "SEQ_REPORTHISTORYFILE", allocationSize = 1)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_REPORTHISTORYFILE_GEN")
private Long fileId;
// note the basic lazy setting
#Basic(fetch = FetchType.LAZY)
#Column(name = "FILE_CONTENT", nullable = false)
private byte[] fileContent;
#Column(name = "FILE_NAME", nullable = false)
private String fileName;
private String contentType;
#Column(name = "FILE_SIZE")
private Long fileSize;
#Column(name = "CREATEDATE")
private Date createDate;
public ReportHistoryFile() {
}
public Long getFileId() {
return fileId;
}
public void setFileId(Long fileId) {
this.fileId = fileId;
}
public byte[] getFileContent() {
if (fileContent == null) {
return null;
}
return Arrays.copyOf(fileContent, fileContent.length);
}
public void setFileContent(byte[] fileContentIn) {
if (fileContentIn != null) {
this.fileContent = Arrays.copyOf(fileContentIn, fileContentIn.length);
}
}
public String getFileName() {
return fileName;
}
public void setFileName(String fileName) {
this.fileName = fileName;
}
public String getContentType() {
return contentType;
}
public void setContentType(String contentType) {
this.contentType = contentType;
}
public Long getFileSize() {
return fileSize;
}
public void setFileSize(Long fileSize) {
this.fileSize = fileSize;
}
public void setCreateDate(Date createDate) {
this.createDate = createDate;
}
public Date getCreateDate() {
return this.createDate;
}
}
But when I execute this code (em is the EntityManager):
List<ReportHistoryFile> list = null;
try {
list = (List<ReportHistoryFile>) em.createNamedQuery("ReportHistoryFile.findAll")
.getResultList();
} catch (javax.persistence.NoResultException e) {
log.info("No Report History File records found.");
} catch (Exception e) {
log.error(e.getMessage(), e);
}
I see this printed out to the console:
[EL Fine]: sql: 2017-01-25 10:35:44.223--ServerSession(1159663071)--Connection(39105078)--SELECT FILEID, CONTENTTYPE, CREATEDATE, FILE_CONTENT, FILE_NAME, FILE_SIZE FROM REPORT_HISTORY_FILES ORDER BY CREATEDATE DESC
Notice that FILE_CONTENT is still in the statement. What am I missing? I don't think I need anything special in my persistence.xml file for just the basic lazy load, but I could be wrong. Thanks in advance!

Answer 1

In order to enable lazy loading feature for properties and relations, your classes must be weaved by eclipseLink using
static weaving
dynamic weaving
How to do this you can read here, working example can be found here