Storing BLOB in Database Spring Hibernate Persistence - java

This is a problem iv encountered and tried most of the solutions that i have been offered so far and little seems to work , the problem making this harder to fix is for some reason the hibernate session wont print its details to the log providing me with very little in terms of error tracing. I want to upload a string of Json converted to a blob into the database . If anyone knows where i am going wrong or can provide and pointers this would be great as im struggling to solve this alone.
#Entity
#Table(name="workout")
public class Workout implements Serializable{
private static Logger logger = Logger.getLogger(Workout.class);
#Id
#Column(name="workout_id")
private int workout_id;
#Column(name="username")
private String username;
#Column(name="added_date")
private String added_date;
#Lob
#Column(name="workout")
Blob workout;
public int getWorkout_id() {
return workout_id;
}
public void setWorkout_id(int workout_id) {
this.workout_id = workout_id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getAdded_date() {
return added_date;
}
public void setAdded_date(String added_date) {
this.added_date = added_date;
}
public Blob getWorkout() {
return workout;
}
public void setWorkout(Blob workout) {
this.workout = workout;
}
}
method from Service that trys to upload
public String uploadWorkout(String json){
Workout w = new Workout();
w.setUsername("cmac458");
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
w.setAdded_date(date.toGMTString());
w.setWorkout(getBLOBfromJSON(json));
w.setWorkout_id(4);
workoutDao.getSession().save(w);
return "done";
}
I am using the basic hibernatetemplate.save(entity) that works in other parts of my application.
Any help here is much appreciated.
Thanks
Chris

I use byte[] instead ob Blob type, and that works fine.
#Lob
#Column(nullable = false, length = 2097152)
private byte[] data;

Related

Android Room Base64

I am trying to save a base64 value into my sqlite database using Room and for some reason it's not saving. Well, i'm assuming it's not saving because when I try to read the table that has the base64 column, it returns values for all the other columns except the base64 column. What am I doing wrong?
My Entity:
#Entity(tableName = "healthCareWorkerInformation",
foreignKeys = #ForeignKey(
entity = HealthCareWorker.class,
parentColumns = {"id"},
childColumns = {"hcwId"},
onDelete = ForeignKey.CASCADE),
indices = #Index(
value = {"hcwId"}))
public class HealthCareWorkersInformation {
#PrimaryKey(autoGenerate = true)
#ColumnInfo(name = "hcwInfoId")
private long id;
private long hcwId;
//#ColumnInfo(typeAffinity = ColumnInfo.BLOB)
private String base64Image;
private String updatedAt = new SimpleDateFormat("dd MM yyyy, HH:mm",
Locale.getDefault()).format(Calendar.getInstance().getTime());
public HealthCareWorkersInformation() {
}
#Ignore
public HealthCareWorkersInformation(long hcwId) {
this.hcwId = hcwId;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public long getHcwId() {
return hcwId;
}
public void setHcwId(long hcwId) {
this.hcwId = hcwId;
}
public String getBase64Image() {
return base64Image;
}
public void setBase64Image(String base64Image) {
this.base64Image = base64Image;
}
public String getUpdatedAt() {
return updatedAt;
}
public void setUpdatedAt(String updatedAt) {
this.updatedAt = updatedAt;
}
}
My DAO:
#Insert
void insertHealthCareWorkerInformation(HealthCareWorkersInformation healthCareWorkersInformation);
#Query("SELECT * FROM HEALTHCAREWORKERINFORMATION")
LiveData<List<HealthCareWorkerInformation>> getHCWInfo();
Sample data I send through:
{"consentGiven":null,"hcwId":1,"patiendId":1,"name":"Ben","lastName":"Ben","dateOfBirth":"4/9/2019","phoneNumber":"+271234567","base64Image":"data:image/png;base64,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"}
Everything else gets saved except for the base64 column. Please assist.
The problem is the semicolon in data:image/png;base64, in combination with " double quotes.
The most easy would be to save the base64 string without that prefix, which breaks the syntax and then assume it is all PNG images (or add a further field, which indicates the encoding of each image).
This problem isn't specific to Room, but specific to Java with SQLite, because that semicolon terminates the statement (which Room will generate). In Java, one can use ' single-quotes only for the primitive data-type char, while the complex data-type String excepts " double-quotes. The only way to get around this limitation, is not trying to save a String containing a ;.
To provide an example of what I mean:
private String base64String = null;
private String base64Type = "png";
public String getBase64Image() {
if(this.base64String != null) {
return "data:image/" + this.base64Type + ";base64," + this.base64String;
} else {
return null;
}
}

Dynamodb versioing with dynamodb mapper is not working as expected

I am getting conditionalcheckfailed exception when trying to save/update items using dynamodb mapper.
Can anyone please share snippet of code using java that can demonstrate how versioning and optimistic locking can be implemented successfully?
Tried not setting version at all!!
Tried adding a record to table, and then doing read before save.
Nothing woked!! I continue to get ConditionalCheckFailed Exception.
Only thing works is if I set the config to COBBLER!! but that's not what I want as I need optimistic locking for my data.
DB item class---
#DynamoDBTable(tableName="Funds")
public class FundsItem {
private String id;
private String auditId;
private Long version;
private String shopId;
private String terminalId;
private String txId;
#DynamoDBHashKey(attributeName = "Id")
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
#DynamoDBRangeKey(attributeName = "AuditId")
public String getAuditId() {
return auditId;
}
public void setAuditId(String auditId) {
this.auditId = auditId;
}
#DynamoDBVersionAttribute(attributeName = "Version")
public Long getVersion() { return version; }
public void setVersion(Long version) { this.version = version; }
#DynamoDBAttribute(attributeName = "ShopId")
public String getShopId() {
return shopId;
}
public void setShopId(String shopId) {
this.shopId = shopId;
}
#DynamoDBAttribute(attributeName = "TerminalId")
public String getTerminalId() { return terminalId; }
public void setTerminalId(String terminalId) {
this.terminalId = terminalId;
}
#DynamoDBAttribute(attributeName = "TxId")
public String getTxId() {
return txId;
}
public void setTxId(String txId) {
this.txId = txId;
}
}
Code to save new item -----
public long addFunds(FundsRequest request){
FundsItem dbItem = new FundsItem();
String Id = request.getShopId().trim() + request.getTerminalId().trim();
String V0_Audit_Rec = "V0_Audit_" + Id;
//save V0 item.
dbItem.setVersion((long) 1);
dbItem.setId(Id);
dbItem.setAuditId(V0_Audit_Rec);
dbItem.setShopId(request.getShopId().trim());
dbItem.setTerminalId(request.getTerminalId().trim());
dbItem.setTxId(request.getTxId().trim());
mapper.save(dbItem);
}
Pls check the snippet above - This is a new empty table.
hashkey - id, rangekey - auditId, VersionField - version.
I just want to be able to add a new record that's why not doing any read before saving a new item. If I can get this simple case i.e. adding a new /first record to the dynamodb table work, I can implement rest of the use cases too.
In general:
Never set your version, the SDK will initialise this if required.
Always try and load an item with your key first. If null is returned, create the item and save it. Else update the returned item and save it.
I know you mentioned you've tried the above. If its truely an empty table your code should work OK (minus the setting of the version).
A couple of things I would also do:
Don't set your version field with a custom attribute name. In theory this should be fine, but for the sake of making your code the same as the AWS examples, I would remove this, at least until you have it working.
Although I think you need to remove the setting of the version, I note you are casting to a long, not a Long. Again, unlikely to be an issue but just something to eliminate at least. i.e. if you insist of setting version use new Long(l).

Hibernate: Program run persists new created entities together with entities which were persisted in previous program run and which I had deleted

This is maybe a beginner question on hibernate. I am doing my first steps, I designed a simple datamodel consisting of about 10 entities and I use hibernate to persist them to my Oracle XE database. Now I am facing the following problem: First time, when I do a transaction to persist some entities, they are persisted properly. I verify, that the data exists in the database and then I delete all the entries from all database tables. I verify that all tables are empty again. Then I run my program again to persist some new entities - and here happens something really strange: Afterwards I find in my databse the new entries as well as the old ones, which were persisted last time and which I had deleted! They contained the old IDs and the old data fields! How can this be? This happens even if I shut down my computer after the first time the program runs! How does it remember the old entries and where are they saved? Do you have any ideas?
Some information, that might be useful:
I am using annotations (instead of config files) for the mapping.
Following you see the classes used for persisting as well as one example of an entity (I am showing only one entity to avoid making the question too long).
As you see, I am using FetchType = EAGER on my MANY to MANY mappings (as I understand, this makes sure, that all related entities are loaded immediately together with any loaded entity). Can this have any impact?
Thanks for any help!
public class PersistenceManager {
private static final SessionFactory factory = new Configuration().configure().buildSessionFactory();
public static void sampleData() {
try(Session session = factory.openSession()) {
SampleDataLoader.loadSampleData(session);
} catch(HibernateException e) {
System.out.println("Exception during persisting! Message: " + e.getMessage());
e.printStackTrace();
}
}
}
public class SampleDataLoader {
static void loadSampleData(Session session) {
Language french = new Language("French");
Language german = new Language("German");
Noun garcon = new Noun(french, "garcon", false);
Noun junge = new Noun(german, "Junge", false);
junge.addTranslation(garcon);
ZUser user = new ZUser("Daniel", "password");
user.setOwnLanguage(german);
user.setEmail("abc#somemail.de");
user.setDateRegistered(LocalDateTime.now());
user.addForeignLanguage(french);
Transaction transaction = session.beginTransaction();
session.save(user);
session.save(french);
session.save(german);
session.save(junge);
transaction.commit();
}
}
#Entity
public class ZUser {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
#Column(name = "id")
private int id;
#Column
private String name;
#Column
private String password;
#Column
private String email;
#Column
private String picturePath;
#Column
private LocalDateTime dateRegistered;
#ManyToOne(fetch=FetchType.EAGER)
#JoinColumn(name="OWNLANGUAGE_ID")
private Language ownLanguage;
#ManyToMany(cascade = { CascadeType.ALL })
#JoinTable(name="USER_LANGUAGE",
joinColumns=#JoinColumn(name="USER_ID"),
inverseJoinColumns=#JoinColumn(name="LANGUAGE_ID")
)
private Set<Language> foreignLanguages = new HashSet<>();
public ZUser() { }
public ZUser(String n, String p) {
name = n;
password = p;
}
public int getId() { return id; }
public void setId(int id) { this.id = id; }
public String getName() { return name; }
public void setName(String name) { this.name = name; }
public String getPassword() { return password; }
public void setPassword(String password) { this.password = password; }
public String getEmail() { return email; }
public void setEmail(String email) { this.email = email; }
public String getPicturePath() { return picturePath; }
public void setPicturePath(String picturePath) { this.picturePath = picturePath; }
public LocalDateTime getDateRegistered() { return dateRegistered; }
public void setDateRegistered(LocalDateTime dateRegistered) { this.dateRegistered = dateRegistered; }
public Language getOwnLanguage() { return ownLanguage; }
public void setOwnLanguage(Language ownLanguage) { this.ownLanguage = ownLanguage; }
public void addForeignLanguage(Language language) {foreignLanguages.add(language);}
public Set<Language> getForeignLanguages() {return Collections.unmodifiableSet(foreignLanguages); }
}
Clarified by the comment of Jagger (see comments). Indeed, I was using Oracle SQL command line to delete the entries and I had rgotten, that I need to explicitely commit after deleting. The solution can be so easy :)

Sending Entity Object in Response which contains blob

I am trying to create a springboot usermanagement application.
I have an entity object which contains two blob elements.Here is my entity object.
#Entity
#Table(name="user_meta_profile")
public class UserMetaProfile implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "user_id")
private int user_id;
#Column(name = "resume_file")
#Lob
private Blob resume_file;
#Column(name = "photo")
#Lob
private Blob photo;
#Column(name = "username")
private String username;
public int getUser_id() {
return user_id;
}
public void setUser_id(int user_id) {
this.user_id = user_id;
}
public Blob getResume_file() {
return resume_file;
}
public void setResume_file(Blob resume_file) {
this.resume_file = resume_file;
}
public Blob getPhoto() {
return photo;
}
public void setPhoto(Blob photo) {
this.photo = photo;
}
public void setUsername(String username) {
this.username = username;
}
}
As you can see there are two blob items 'resume_file' and 'photo'.
I want to send back a JSON response to the API call.
My Controller code is as shown below.
#Controller
#RequestMapping("/v1")
public class UsersController {
#Autowired
private IUserMetaProfileService userMetaProfileService;
#GetMapping("MetaProfile/{id}")
public ResponseEntity<UserMetaProfile> getUserMetaProfileById(#PathVariable("id") Integer id) {
UserMetaProfile userMetaProfile = userMetaProfileService.getUsersById(id);
return new ResponseEntity<UserMetaProfile>(userMetaProfile, HttpStatus.OK);
}
}
But when I call the API, I get the exception:
"exception": "org.springframework.http.converter.HttpMessageNotWritableException",
"message": "Could not write JSON document: No serializer found for class java.io.ByteArrayInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain:
...
...nested exception is com.fasterxml.jackson.databind.JsonMappingException: No serializer found for class java.io.ByteArrayInputStream and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)
Since JSON cannot contain binary data you need to serialize those fields as something else. You have a couple of options:
If you intend to show the binary as an image (since yours is a photo) you can serialize it as a data uri.
Send links to photos instead and create a controller method that will output the binary data with the appropriate content type (beyond the scope here).
So for Option 1 you can do something like this:
#Entity
#Table(name="user_meta_profile")
public class UserMetaProfile implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name = "user_id")
private int user_id;
#Column(name = "resume_file")
#Lob
private Blob resume_file;
#Column(name = "photo")
#Lob
private Blob photo;
#Column(name = "username")
private String username;
public int getUser_id() {
return user_id;
}
public void setUser_id(int user_id) {
this.user_id = user_id;
}
#JsonIgnore // disable serializing this field by default
public Blob getResume_file() {
return resume_file;
}
// serialize as data uri insted
#JsonProperty("resumeData")
public String getResume() {
// just assuming it is a word document. you would need to cater for different media types
return "data:application/vnd.openxmlformats-officedocument.wordprocessingml.document;base64," + new String(Base64.getEncoder().encode(resume_file.getBytes()));
}
public void setResume_file(Blob resume_file) {
this.resume_file = resume_file;
}
#JsonIgnore // disable this one too
public Blob getPhoto() {
return photo;
}
// serialize as data uri instead
#JsonProperty("photoData")
public String getPhotoBase64() {
// just assuming it is a jpeg. you would need to cater for different media types
return "data:image/jpeg;base64," + new String(Base64.getEncoder().encode(photo.getBytes()));
}
public void setPhoto(Blob photo) {
this.photo = photo;
}
public void setUsername(String username) {
this.username = username;
}
}
For the photo bit the value of the photoData JSON attribute can be set directly as the src attribute of an img tag and the photo will be rendered in the HTML. With the resume file you can attach it as an href to a <a> tag with a download attribute so it can be downloaded:
<a href={photoData value here} download>Download Resume File</a>
Just as an FYI if the files are large the JSON will be huge and it might also slow down the browser.

Different serialization/deserialization names with java jackson

I want to be able to have different names for serialized and deserialized json objects when using jackson in java.
To be a bit more concrete: I am getting data from an API that is using one name standard on their JSON attributes, but my endpoints use a different one, and as I in this case just want to pass the data along I would like to be able to translate the attributes to my name standard.
I have read similar questions on here, but I simply can't seem to get it working.
private String defaultReference;
#JsonProperty(value = "default_reference", access = JsonProperty.Access.WRITE_ONLY)
public void setDefaultReference(String defaultReference)
{
this.defaultReference = defaultReference;
}
#JsonProperty(value = "defaultReference", access = JsonProperty.Access.READ_ONLY)
public String getDefaultReference()
{
return defaultReference;
}
That is my latest attempt. problem with this is that it always returns null, so the setter is not used.
I have also tried:
#JsonProperty(value = "default_reference", access = JsonProperty.Access.WRITE_ONLY)
private String defaultReference;
#JsonProperty(value = "defaultReference", access = JsonProperty.Access.READ_ONLY)
public String getDefaultReference()
{
return defaultReference;
}
This sort of works. It can deserialize default_reference. Problem is that in my JSON response I get both default_reference and defaultReference. Preferably I would only get defaultReference.
Has anyone done anything similar and see what is wrong with what I've tried?
You're on the right track. Here's an example of this working with a test JSON document.
public static class MyClass {
private String defaultReference;
#JsonProperty(value = "default_reference")
public void setDefaultReference(String defaultReference) {
this.defaultReference = defaultReference;
}
#JsonProperty(value = "defaultReference")
public String getDefaultReference() {
return defaultReference;
}
public static void main(String[] args) throws IOException {
ObjectMapper objectMapper = new ObjectMapper();
MyClass instance = objectMapper.readValue("{\"default_reference\": \"value\"}", MyClass.class);
objectMapper.writeValue(System.out, instance);
// Output: {"defaultReference":"value"}
}
}
Another Alternative is
#JsonSetter("default_reference")
public void setDefaultReference(String defaultReference) {
this.defaultReference = defaultReference;
}
#JsonGetter("defaultReference")
public String getDefaultReference() {
return defaultReference;
}

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