When I delete my neo4j database after my tests like this
public static final DatabaseOperation clearDatabaseOperation = new DatabaseOperation() {
#Override public void performOperation(GraphDatabaseService db) {
//This is deprecated on the GraphDatabaseService interface,
// but the alternative is not supported by implementation (RestGraphDatabase)
for (Node node : db.getAllNodes()) {
for (Relationship relationship : node.getRelationships()) {
relationship.delete();
}
boolean notTheRootNode = node.getId() != 0;
if (notTheRootNode) {
node.delete();
}
}
When querying the database through an ajax search (i.e searching on an empty database it returns an internal 500 error)
localhost:9000/search-results?keywords=t 500 Internal Server Error
197ms
However if I delete the database manually like this
start r=relationship(*) delete r;
start n=node(*) delete n;
No exception is thrown
Its most likely an issue with my code at a lower level in the call and return.
Just wandering why the error only works on one of the scenarios above and not both
Use cypher,
you should probably state more obviously that you use the rest-graph-database.
Are you querying after the deletion or during it?
Please check your logs in data/graph.db/messages.log and data/log/console.log to find the error cause.
Perhaps you can also look at the response body of the http-500 request
As per your error I guess your data is getting corrupted after deletion.
I have used same code like yours and deleted the nodes, except I put the Iterator in transaction and shut down the database after opetation.
e.g.
Transaction _tx = _db.beginTx();
try {
for ( your conditions){
Your code
}
_tx.success();
} catch (Exception e) {
_logger.error(e.getMessage());
}finally{
_tx.finish();
_db.shutdown();
graphDbFactory.cleanUp();
}
Hope it will work for you.
Related
I am newbie to MongoDB i implemented transactional feature in one of my application, as per my requirements i need to persist data into different collections in the same database. Below is the code snippet for the same
In Tuple3 first element is database, second element is collection and third element is data i want to persist which is coming as json string which i am converting to bson document
ClientSession clientSession = mongoClient.startSession();
try {
clientSession.startTransaction(transactionOptions);
for (Tuple3<String, String, String> value: insertValues) {
MongoCollection<Document> collection = mongoClient
.getDatabase(insertValues.f0)
.getCollection(insertValues.f1);
Document data= Document.parse(insertValues.f2);
log.info(String.format("Inserting data into database %s and collection is %s", insertValues.f0, insertValues.f1));
collection.insertOne(clientSession, data);
clientSession.commitTransaction();
}
} catch (MongoCommandException | MongoWriteException exception) {
clientSession.abortTransaction();
log.error(String.format("Exception happened while inserting record into Mongo DB rolling back the transaction " +
"and cause of exception is: %s", exception));
} finally {
clientSession.close();
}
Below are transaction options i am using
TransactionOptions transactionOptions = TransactionOptions.builder().readConcern(ReadConcern.LOCAL).writeConcern(WriteConcern.W1).build();
Below is MongoClient method with MongoClientOptions i am taking Mongo DB Connection string as input to this method
public MongoClient getTransactionConnection(String connectionString) {
MongoClientOptions.Builder mongoClientOptions = new MongoClientOptions.Builder()
.readConcern(ReadConcern.LOCAL)
.writeConcern(WriteConcern.W1)
.readPreference(ReadPreference.primary())
.serverSelectionTimeout(120000)
.maxWaitTime(120000)
.connectionsPerHost(10)
.connectTimeout(120000);
MongoClientURI uri = new MongoClientURI(connectionString, mongoClientOptions);
return new MongoClient(uri);
}
Till here it is good and it is inserting data to three different collection under the specified database. But when i try to some negative scenario i am trying to throw exception in try block which ideally should rollback the data for that particular client session if any error happens.
I am trying to throw exception by using count variable which will increment and for if count value is equal to 1 i am throwing exception which should abort the transaction and rollback if any data is written to database but what i am seeing it is writing to one of the collection and throws exception after that stops the program but it is not rolling back the data written to collection actually. I am trying something like this below
ClientSession clientSession = mongoClient.startSession();
int count = 0;
try {
clientSession.startTransaction(transactionOptions);
for (Tuple3<String, String, String> value: insertValues) {
MongoCollection<Document> collection = mongoClient
.getDatabase(insertValues.f0)
.getCollection(insertValues.f1);
Document data= Document.parse(insertValues.f2);
log.info(String.format("Inserting data into database %s and collection is %s", insertValues.f0, insertValues.f1));
collection.insertOne(clientSession, data);
if(count == 1){
throw new MongoException("Aborting transaction.....");
}
count++;
clientSession.commitTransaction();
}
} catch (MongoCommandException | MongoWriteException exception) {
clientSession.abortTransaction();
log.error(String.format("Exception happened while inserting record into Mongo DB rolling back the transaction " +
"and cause of exception is: %s", exception));
} finally {
clientSession.close();
}
I am not sure where i am going wrong i am using Mongo DB version 4.0 deployed using Azure CosmosDB Api. Please help me in resolving this issue thanks in advance.
Cosmos DB does not have transaction support outside of a single partition (shard) of a single collection. This limitation exists regardless of API in use (in your case, MongoDB API). This is why you're not seeing the behavior you're expecting. Note: this is mentioned in the Cosmos DB MongoDB compatibility docs.
You'll need to come up with your own implementation for managing data consistency within your app.
I work on university project in java. I have to download attachments from new emails using GMAIL API.
I successfully connected to gmail account using OAuth 2.0 authorization.
private static final List<String> SCOPES = Collections.singletonList(GmailScopes.GMAIL_READONLY);
I tried to get unseen mails using
ListMessagesResponse listMessageResponse = service.users().messages().list(user).setQ("is:unseen").execute();
listMessageResponse is not null but when I call method .getResultSizeEstimate() it returns 0
also I tried to convert listMessageResponse to List < Message > (I guess this is more usable) using
List<Message> list = listMessageResponse.getMessages();
But list launches NullPointerException
Then tried to get each attachment with
for(Message m : list) {
List<MessagePart> part = m.getPayload().getParts();
for(MessagePart p: part) {
if(p.getFilename()!=null && p.getFilename().length()>0) {
System.out.println(p.getFilename()); // Just to check attachment filename
}
}
}
Is my approach correct (if not how to fix it) and how should I download those attachments.
EDIT 1:
Fixed q parameter, I mistakenly wrote is:unseen instead of is:unread.
Now app reaches unread mails successfully.
(For example there was two unread mails and both successfully reached, I can get theirs IDs easy).
Now this part trows NullPointerException
List<MessagePart> part = m.getPayload().getParts();
Both messages have attachments and m is not null (I get ID with .getID())
Any ideas how to overcome this and download attachment?
EDIT 2:
Attachments Downloading part
for(MessagePart p : parts) {
if ((p.getFilename() != null && p.getFilename().length() > 0)) {
String filename = p.getFilename();
String attId = p.getBody().getAttachmentId();
MessagePartBody attachPart;
FileOutputStream fileOutFile = null;
try {
attachPart = service.users().messages().attachments().get("me", p.getPartId(), attId).execute();
byte[] fileByteArray = Base64.decodeBase64(attachPart.getData());
fileOutFile = new FileOutputStream(filename); // Or any other dir
fileOutFile.write(fileByteArray);
fileOutFile.close();
}catch (IOException e) {
System.out.println("IO Exception processing attachment: " + filename);
} finally {
if (fileOutFile != null) {
try {
fileOutFile.close();
} catch (IOException e) {
// probably doesn't matter
}
}
}
}
}
Downloading working like charm, tested app with different type of emails.
Only thing left is to change label of unread message (that was reached by app) to read. Any tips how to do it?
And one tiny question:
I want this app to fetch mails on every 10 minutes using TimerTask abstract class. Is there need for manual "closing" of connection with gmail or that's done automatically after run() method iteration ends?
#Override
public void run(){
// Some fancy code
service.close(); // Something like that if even exists
}
I don't think ListMessagesResponse ever becomes null. Even if there are no messages that match your query, at least resultSizeEstimate will get populated in the resulting response: see Users.messages: list > Response.
I think you are using the correct approach, just that there is no message that matches your query. Actually, I never saw is:unseen before. Did you mean is:unread instead?
Update:
When using Users.messages: list only the id and the threadId of each message is populated, so you cannot access the message payload. In order to get the full message resource, you have to use Users.messages: get instead, as you can see in the referenced link:
Note that each message resource contains only an id and a threadId. Additional message details can be fetched using the messages.get method.
So in this case, after getting the list of messages, you have to iterate through the list, and do the following for each message in the list:
Get the message id via m.getId().
Once you have retrieved the message id, use it to call Gmail.Users.Messages.Get and get the full message resource. The retrieved message should have all fields populated, including payload, and you should be able to access the corresponding attachments.
Code sample:
List<Message> list = listMessageResponse.getMessages();
for(Message m : list) {
Message message = service.users().messages().get(user, m.getId()).execute();
List<MessagePart> part = message.getPayload().getParts();
// Rest of code
}
Reference:
Class ListMessagesResponse
Users.messages: list > Response
We are fetching the list of namespaces from datastore which counts upto 30k.
The cron to fetch namespaces runs daily. But one day it works fine and other day it throws datastore timeout exception.
com.google.appengine.api.datastore.DatastoreTimeoutException: The
datastore operation timed out, or the data was temporarily
unavailable.
Related Code :
DatastoreService ds = DatastoreServiceFactory.getDatastoreService();
FetchOptions options = FetchOptions.Builder.withChunkSize(150);
Query q = new Query(Entities.NAMESPACE_METADATA_KIND);
for (Entity e : ds.prepare(q).asIterable(options)){
// A nonzero numeric id denotes the default namespace;
// see Namespace Queries, below
if (e.getKey().getId() != 0){
continue;
}else{
namespaces.add(e.getKey().getName());
}
}
What could be the issue?
According to official documentation:
DatastoreTimeoutException is thrown when a datastore operation times
out. This can happen when you attempt to put, get, or delete too many
entities or an entity with too many properties, or if the datastore is
overloaded or having trouble.
This means that datastore having troubles with your request. Try to handle that error like:
import com.google.appengine.api.datastore.DatastoreTimeoutException;
try {
// Code that could result in a timeout
} catch (DatastoreTimeoutException e) {
// Display a timeout-specific error page
}
I have some method in my DAO class:
public void insertAVAYAcmCDRs(List<AvayaCmCdr> cdrList) {
AvayaCmCdr aCdrList1 = null;
try {
em.getTransaction().begin();
for (AvayaCmCdr aCdrList : cdrList) {
aCdrList1 = aCdrList;
em.persist(aCdrList);
}
em.getTransaction().commit();
em.clear();
} catch (Exception e) {
logger.log(Level.INFO, "Exception in task time={0}. Exception message = {1}.", new Object[]{aCdrList1.getDate(), e.getMessage()});
}
}
I tried save all array entities to DB. But in DB i have uniqe index - it does not allow to insert duplicate rows. It work normaly on DB side but i have some error in java.
a different object with the same identifier value was already associated with the session:
I get this error on 2 step of cycle. I print this object and found dublicate in DB.
I want ignore this error and continue insert data or somehow handle the error.
if this row already in the database i want ignore and skip it and continue insert
Why are you assigning this aCdrList1 = aCdrList ? Is there any specific reason?
you can save aCdrList object. Use below one
em.saveOrUpdate(aCdrList);
or
em.merge(aCdrList);
I am using UnboundID-LDAPSDK (2.3.8) to change the user's photo in our Microsoft Active Directory.
LDAPConnection ldap = null;
try {
ldap = new LDAPConnection("domain-srv", 389, "CN=admin,OU=Users,OU=ADM,DC=domain,DC=local", "password");
SearchResult sr = ldap.search("DC=domain,DC=local", SearchScope.SUB, "(sAMAccountName=" + getUser().getUsername() + ")");
if (sr.getEntryCount() == 1) {
SearchResultEntry entry = sr.getSearchEntries().get(0);
entry.setAttribute("thumbnailPhoto", getUser().getPhotoAsByteArray());
ldap.close();
return true;
} else
return false;
} catch (LDAPException e) {
e.printStackTrace();
}
But I get a java.lang.UnsupportedOperationException.
The documentation for setAttribute states:
Throws an UnsupportedOperationException to indicate that this is a
read-only entry.
I also tried to change the postalCode but I get the same exception.
Changing those attributes should be possible, because I can change them with jXplorer.
Do I have to enable a write-mode somehow?
Thank you
The SearchResultEntry object extends ReadOnlyEntry and is therefore immutable. But even if it weren't, merely calling entry.setAttribute would have no effect on the data in the server. You have to use a modify operation for that.
To do that, you'd need something like:
ModifyRequest modifyRequest = new ModifyRequest(entry.getDN(),
new Modification(ModificationType.REPLACE,
"thumbnailPhoto", getUser().getPhotoAsByteArray());
ldap.modify(modifyRequest);
Also, you should put the call to ldap.close() in a finally block because as the code is written now, you're only closing the connection if the search is successful and returns exactly one entry, but not if the search fails, doesn't match any entries, or the attempt to perform the modify fails.