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  • Large ResultSet on postgresql query

    - by tuler
    I'm running a query against a table in a postgresql database. The database is on a remote machine. The table has around 30 sub-tables using postgresql partitioning capability. The query will return a large result set, something around 1.8 million rows. In my code I use spring jdbc support, method JdbcTemplate.query, but my RowCallbackHandler is not being called. My best guess is that the postgresql jdbc driver (I use version 8.3-603.jdbc4) is accumulating the result in memory before calling my code. I thought the fetchSize configuration could control this, but I tried it and nothing changes. I did this as postgresql manual recomended. This query worked fine when I used Oracle XE. But I'm trying to migrate to postgresql because of the partitioning feature, which is not available in Oracle XE. My environment: Postgresql 8.3 Windows Server 2008 Enterprise 64-bit JRE 1.6 64-bit Spring 2.5.6 Postgresql JDBC Driver 8.3-603

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  • How do I recover from an unchecked exception?

    - by erickson
    Unchecked exceptions are alright if you want to handle every failure the same way, for example by logging it and skipping to the next request, displaying a message to the user and handling the next event, etc. If this is my use case, all I have to do is catch some general exception type at a high level in my system, and handle everything the same way. But I want to recover from specific problems, and I'm not sure the best way to approach it with unchecked exceptions. Here is a concrete example. Suppose I have a web application, built using Struts2 and Hibernate. If an exception bubbles up to my "action", I log it, and display a pretty apology to the user. But one of the functions of my web application is creating new user accounts, that require a unique user name. If a user picks a name that already exists, Hibernate throws an org.hibernate.exception.ConstraintViolationException (an unchecked exception) down in the guts of my system. I'd really like to recover from this particular problem by asking the user to choose another user name, rather than giving them the same "we logged your problem but for now you're hosed" message. Here are a few points to consider: There a lot of people creating accounts simultaneously. I don't want to lock the whole user table between a "SELECT" to see if the name exists and an "INSERT" if it doesn't. In the case of relational databases, there might be some tricks to work around this, but what I'm really interested in is the general case where pre-checking for an exception won't work because of a fundamental race condition. Same thing could apply to looking for a file on the file system, etc. Given my CTO's propensity for drive-by management induced by reading technology columns in "Inc.", I need a layer of indirection around the persistence mechanism so that I can throw out Hibernate and use Kodo, or whatever, without changing anything except the lowest layer of persistence code. As a matter of fact, there are several such layers of abstraction in my system. How can I prevent them from leaking in spite of unchecked exceptions? One of the declaimed weaknesses of checked exceptions is having to "handle" them in every call on the stack—either by declaring that a calling method throws them, or by catching them and handling them. Handling them often means wrapping them in another checked exception of a type appropriate to the level of abstraction. So, for example, in checked-exception land, a file-system–based implementation of my UserRegistry might catch IOException, while a database implementation would catch SQLException, but both would throw a UserNotFoundException that hides the underlying implementation. How do I take advantage of unchecked exceptions, sparing myself of the burden of this wrapping at each layer, without leaking implementation details?

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  • JPA entity design / cannot delete entity

    - by timaschew
    I though its simple what I want, but I cannot find any solution for my problem. I'm using playframework 1.2.3 and it's using Hibernate as JPA. So I think playframework has nothing to do with the problem. I have some classes (I omit the nonrelevant fields) public class User { ... } public class Task { public DataContainer dataContainer; } public class DataContainer { public Session session; public User user; } public class Session { ... } So I have association from Task to DataContainer and from DataContainer to Sesssion and the DataContainer belongs to a User. The DataContainers can have always the same User, but the Session have to be different for each instance. And the DataContainer of a Task have also to be different in each instance. A DataContainer can have a Sesesion or not (it's optinal). I use only unidirectional assoc. It should be sufficient. In other words: Every Task must has one DataContainer. Every DataContainer must has one/the same User and can have one Session. To create a DB schema I use JPA annotations: @Entity public class User extends Model { ... } @Entity public class Task extends Model { @OneToOne(optional = false, cascade = CascadeType.ALL) public DataContainer dataContainer; } @Entity public class DataContainer extends Model { @OneToOne(optional = true, cascade = CascadeType.ALL) public Session session; @ManyToOne(optional = false, cascade = CascadeType.ALL) public User user; } @Entity public class Session extends Model { ... } BTW: Model is a play class and provides the primary id as long type. When I create some for each entity a object and 'connect them', I mean the associations, it works fine. But when I try to delete a Session, I get a constraint violation exception, because a DataContainer still refers to the Session I want to delete. I want that the Session (field) of the DataContainer will be set to null respectively the foreign key (session_id) should be unset in the database. This will be okay, because its optional. I don't know, I think I have multiple problems. Am I using the right annotation @OneToOne ? I found on the internet some additional annotation and attributes: @JoinColumn and a mappedBy attribute for the inverse relationship. But I don't have it, because its not bidirectional. Or is a bidirectional assoc. essentially? Another try was to use @OnDelete(action = OnDeleteAction.CASCADE) the the contraint changed from NO ACTIONs when update or delete to: ADD CONSTRAINT fk4745c17e6a46a56 FOREIGN KEY (session_id) REFERENCES annotation_session (id) MATCH SIMPLE ON UPDATE NO ACTION ON DELETE CASCADE; But in this case, when I delete a session, the DataContainer and User is deleted. That's wrong for me. EDIT: I'm using postgresql 9, the jdbc stuff is included in play, my only db config is db=postgres://app:app@localhost:5432/app

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  • how to use JComboBox using Enum in Dialog Box

    - by Edan
    Hi, I define enums: enum itemType {First, Second, Third}; public class Item { private itemType enmItemType; ... } How do I use it inside Dialog box using JComboBox? Means, inside the dialog box, the user will have combo box with (First, Second, Third). Also, is it better to use some sort of ID to each numerator? (Integer) thanks.

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  • JFrame the same shape as an Image / Program running in background

    - by Jan Weber
    My question is simple, the solution surely not. I am looking for a way to shape a JFrame the same as an Image it will be displaying. By shape I mean the shape of the pixels that have an alpha != 0. I've already found a working example using a GeneralPath object, but it created ~110000 "nodes" for an Image of about 500*400, so starting the JFrame took more than 2 minutes, which is definitely not the desired effect, the startup should be in under 2 seconds. Thanks for your time.

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  • Netbeans Clamshell emulator out of memory

    - by Kyle
    Hello, I have been working with the clamshell mobile phone emulator for netbeans. I recently have tested a simple bluetooth application and got an Out of Memory erorr. Is it possible to up the amount of memory the emulator can use? thanks!

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  • JBoss Clustered Service that sends emails from txt file

    - by michael lucas
    I need a little push in the right direction. Here's my problem: I have to create an ultra-reliable service that sends email messages to clients whose addresses are stored in txt file on FTP server. Single txt file may contain unlimited number of entries. Most often the file contains about 300,000 entries. Service exposes interface with just two simple methods: TaskHandle sendEmails(String ftpFilePath); ProcessStatus checkProcessStatus(TaskHandle taskHandle); Method sendEmails() returns TaskHandle by which we can ask for ProcessStatus. For such a service to be reliable clustering is necessary. Processing single txt file might take a long time. Restarting one node in a cluster should have no impact on sending emails. We use JBoss AS 4.2.0 which comes with a nice HASingletonController that ensure one instance of service is running at given time. But once a fail-over happens, the second service should continue work from where the first one stopped. How can I share state between nodes in a cluster in such a way that leaves no possibility of sending some emails twice?

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  • Why do I not see stricter scoping more often?

    - by Ben
    I've found myself limiting scope fairly often. I find it makes code much clearer, and allows me to reuse variables much more easily. This is especially handy in C where variables must be declared at the start of a new scope. Here is an example of what I mean. { int h = 0; foreach (var item in photos) { buffer = t.NewRow(); h = item.IndexOf("\\x\\"); buffer["name"] = item.Substring(h, item.Length - h); t.Rows.Add(buffer); } } With this example, I've limited the scope of h, without initializing it in every iteration. But I don't see many other developers doing this very often. Why is that? Is there a downside to doing this?

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  • Getting fewer columns with hibernate

    - by Gandalf StormCrow
    I have a table with 11 columns, but I need to get only 2 of them in my application, I'm using spring/hibernate/DAO combination. For now I have a domain class which includes all 11 fields, and mapping file which maps all 11 columns in table. How do I use get just 2 of them not all?

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  • Transactions in hibernate

    - by kumar1425
    Hi I new to hibernate In my project, i need to handle transactions. How to handle declarative transactions with in two classes Examples: //class 1 class A{ createA() { insert(A); } } //class 2 class B { createB() { insert(B); } } //class 3 @Transaction(Exception.class) class C { test() { create(A); create(B); } } As per the above code is there any possibility to handle transactions, in such a way that if the insert in classA success and the insert in the classB fails then the transaction should rollback and remove the record inserted in the table A corresponding to the Class A please help me with this using declarative transactions.... Thanks in adavace....

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  • mig layout - span and grow/push problem

    - by pstanton
    i want 3 components laid out on 2 lines, so that the bottom component and the top-right component use all available horizontal space. JFrame frame = new JFrame(); frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); frame.setLayout(new MigLayout("debug, fill")); Container cp = frame.getContentPane(); cp.add(new JTextField("component 1"), ""); cp.add(new JTextField("component 2"), "growx,push,wrap"); cp.add(new JTextField("component 3"), "span,growx,push"); frame.pack(); frame.setVisible(true); considering the above, how do i stop the space between "component 1" and "component 2" from appearing when resizing the frame? thanks.

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  • Progress bar increment by 1 every 100th of second

    - by Matthew De'Loughry
    I'm trying to get a JProgressBar to increment by 1 every 100th of a second, and at the moment I'm using Thread.sleep(100) inside a while statement like so: try { while (i<=100){ doTime(); } } catch (InterruptedException ex) { Logger.getLogger(SplashScreen.class.getName()).log(Level.SEVERE, null, ex); } public void doTime() throws InterruptedException{ jLabel1.setText("sleeping"); Thread.sleep(100); jLabel1.setText("start"); i++; pb.setValue(i); pb.repaint(); } and If I debug by doing a System.out.println it displays in real time but the swing GUI freezes until it drops out of the while loop can anyone help? thanks matt

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  • @NamedQuery select parameter meaning

    - by sergionni
    Found some examples of @NamedQuery annotations,e.g.: @NamedQuery(name="employeeBySsn" query="select e from Employee e where e.ssn = :ssn") what does parameter e mean? the second usage of it seems like alias name of table and what does "select e" part mean?

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  • dynamic button in jsp

    - by kawtousse
    hi everyone, in my jsp i have a table constructed dynamically like the following: retour.append("<tr>"); try { s= HibernateUtil.currentSession(); tx=s.beginTransaction(); Query query = s.createQuery(HQL_QUERY); for(Iterator it=query.iterate();it.hasNext();) { if(it.hasNext()){ Dailytimesheet object=(Dailytimesheet)it.next(); retour.append("<td>" +object.getActivity() +"</td>"); retour.append("<td>" +object.getProjectCode() + "</td>"); retour.append("<td>" +object.getWAName() + "</td>"); retour.append("<td>" +object.getTaskCode() +"</td>"); retour.append("<td>" +object.getTimeFrom() +"</td>"); retour.append("<td>" +object.getTimeSpent() + "</td>"); retour.append("<td>" +object.getPercentTaskComplete() + "</td>"); if (droitdaccess) { retour.append(""); retour.append(""); retour.append(""); retour.append("<td bordercolor=#FFFFFF>"); retour.append("<input type=\"hidden\" id=\"id_"+nomTab+"_"+compteur+"\" value=\""+object.getIdDailyTimeSheet()+"\"/>"); retour.append("<img src=\"icon_delete.gif\" onClick=\"deletearowById('id_"+nomTab+"_"+compteur+"')\" style=\"cursor:pointer\" name=\"action\" value=\"deleting\" />"); retour.append("</td>"); } } compteur++; retour.append("</tr>"); } //terminer la table. retour.append ("</table>"); next to the table i want to display a button named send in order to send the table content. I do not really want to dispaly this button where the table is empty. So at least if the table is populated by nly one record i want that button being displayed. How should i deal in this case. Thanks.

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  • Configurable Values in Enum

    - by Omer Akhter
    I often use this design in my code to maintain configurable values. Consider this code: public enum Options { REGEX_STRING("Some Regex"), REGEX_PATTERN(Pattern.compile(REGEX_STRING.getString()), false), THREAD_COUNT(2), OPTIONS_PATH("options.config", false), DEBUG(true), ALWAYS_SAVE_OPTIONS(true), THREAD_WAIT_MILLIS(1000); Object value; boolean saveValue = true; private Options(Object value) { this.value = value; } private Options(Object value, boolean saveValue) { this.value = value; this.saveValue = saveValue; } public void setValue(Object value) { this.value = value; } public Object getValue() { return value; } public String getString() { return value.toString(); } public boolean getBoolean() { Boolean booleanValue = (value instanceof Boolean) ? (Boolean) value : null; if (value == null) { try { booleanValue = Boolean.valueOf(value.toString()); } catch (Throwable t) { } } // We want a NullPointerException here return booleanValue.booleanValue(); } public int getInteger() { Integer integerValue = (value instanceof Number) ? ((Number) value).intValue() : null; if (integerValue == null) { try { integerValue = Integer.valueOf(value.toString()); } catch (Throwable t) { } } return integerValue.intValue(); } public float getFloat() { Float floatValue = (value instanceof Number) ? ((Number) value).floatValue() : null; if (floatValue == null) { try { floatValue = Float.valueOf(value.toString()); } catch (Throwable t) { } } return floatValue.floatValue(); } public static void saveToFile(String path) throws IOException { FileWriter fw = new FileWriter(path); Properties properties = new Properties(); for (Options option : Options.values()) { if (option.saveValue) { properties.setProperty(option.name(), option.getString()); } } if (DEBUG.getBoolean()) { properties.list(System.out); } properties.store(fw, null); } public static void loadFromFile(String path) throws IOException { FileReader fr = new FileReader(path); Properties properties = new Properties(); properties.load(fr); if (DEBUG.getBoolean()) { properties.list(System.out); } Object value = null; for (Options option : Options.values()) { if (option.saveValue) { Class<?> clazz = option.value.getClass(); try { if (String.class.equals(clazz)) { value = properties.getProperty(option.name()); } else { value = clazz.getConstructor(String.class).newInstance(properties.getProperty(option.name())); } } catch (NoSuchMethodException ex) { Debug.log(ex); } catch (InstantiationException ex) { Debug.log(ex); } catch (IllegalAccessException ex) { Debug.log(ex); } catch (IllegalArgumentException ex) { Debug.log(ex); } catch (InvocationTargetException ex) { Debug.log(ex); } if (value != null) { option.setValue(value); } } } } } This way, I can save and retrieve values from files easily. The problem is that I don't want to repeat this code everywhere. Like as we know, enums can't be extended; so wherever I use this, I have to put all these methods there. I want only to declare the values and that if they should be persisted. No method definitions each time; any ideas?

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  • Lost with hibernate - OneToMany resulting in the one being pulled back many times..

    - by Andy
    I have this DB design: CREATE TABLE report ( ID MEDIUMINT PRIMARY KEY NOT NULL AUTO_INCREMENT, user MEDIUMINT NOT NULL, created TIMESTAMP NOT NULL, state INT NOT NULL, FOREIGN KEY (user) REFERENCES user(ID) ON UPDATE CASCADE ON DELETE CASCADE ); CREATE TABLE reportProperties ( ID MEDIUMINT NOT NULL, k VARCHAR(128) NOT NULL, v TEXT NOT NULL, PRIMARY KEY( ID, k ), FOREIGN KEY (ID) REFERENCES report(ID) ON UPDATE CASCADE ON DELETE CASCADE ); and this Hibernate Markup: @Table(name="report") @Entity(name="ReportEntity") public class ReportEntity extends Report{ @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name="ID") private Integer ID; @Column(name="user") private Integer user; @Column(name="created") private Timestamp created; @Column(name="state") private Integer state = ReportState.RUNNING.getLevel(); @OneToMany(mappedBy="pk.ID", fetch=FetchType.EAGER) @JoinColumns( @JoinColumn(name="ID", referencedColumnName="ID") ) @MapKey(name="pk.key") private Map<String, ReportPropertyEntity> reportProperties = new HashMap<String, ReportPropertyEntity>(); } and @Table(name="reportProperties") @Entity(name="ReportPropertyEntity") public class ReportPropertyEntity extends ReportProperty{ @Embeddable public static class ReportPropertyEntityPk implements Serializable{ /** * long#serialVersionUID */ private static final long serialVersionUID = 2545373078182672152L; @Column(name="ID") protected int ID; @Column(name="k") protected String key; } @EmbeddedId protected ReportPropertyEntityPk pk = new ReportPropertyEntityPk(); @Column(name="v") protected String value; } And i have inserted on Report and 4 Properties for that report. Now when i execute this: this.findByCriteria( Order.asc("created"), Restrictions.eq("user", user.getObject(UserField.ID)) ) ); I get back the report 4 times, instead of just the once with a Map with the 4 properties in. I'm not great at Hibernate to be honest, prefer straight SQL but I must learn, but i can't see what it is that is wrong.....? Any suggestions?

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  • Authentication from url in Restlet

    - by DutrowLLC
    I've been using Restlets "ChallengeResponse" mechanism to authenticate users so far. ChallengeResponse challengeResponse = getRequest().getChallengeResponse(); if( challengeResponse == null ){ throw new RuntimeException("not authenticated"); } String login = challengeResponse.getIdentifier(); String password = new String(challengeResponse.getSecret()); From my understanding, "ChallengeResponse" requires that the username and password are put into headers. However a client needs to put the credentials into the url like so: https://username:[email protected]/my_secure_document When I looked at what was actually sent, it looks like the password is being hashed. What is the proper way to authenticate in this fashion using Restlet?

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  • Trying to create spring project with maven

    - by Gandalf StormCrow
    Hello everyone I was just going trough http://static.springsource.org/docs/Spring-MVC-step-by-step/part1.html spring tutorial, and I thought its old I'll think something better on my own. For starters how do I start spring project with maven, which archtype should I choose? I wanna create simple spring app, write class which I will deploy to jboss, spring will instansiate it at startup .. that is what have in mind for now .. for now I need to start it first

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  • JDO, GAE: Load object group by child's key

    - by tiex
    I have owned one-to-many relationship between two objects: @PersistenceCapable(identityType = IdentityType.APPLICATION) public class AccessInfo { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private com.google.appengine.api.datastore.Key keyInternal; ... @Persistent private PollInfo currentState; public AccessInfo(){} public AccessInfo(String key, String voter, PollInfo currentState) { this.voter = voter; this.currentState = currentState; setKey(key); // this key is unique in whole systme } public void setKey(String key) { this.keyInternal = KeyFactory.createKey( AccessInfo.class.getSimpleName(), key); } public String getKey() { return this.keyInternal.getName(); } and @PersistenceCapable(identityType = IdentityType.APPLICATION) public class PollInfo { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Key key; @Persistent(mappedBy = "currentState") private List<AccessInfo> accesses; ... I created an instance of class PollInfo and make it persistence. It is ok. But then I want to load this group by AccessInfo key, and I am getting exception NucleusObjectNotFoundException. Is it possible to load a group by child's key?

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  • Is JPA persistence.xml classpath located?

    - by Vinnie
    Here's what I'm trying to do. I'm using JPA persistence in a web application, but I have a set of unit tests that I want to run outside of a container. I have my primary persistence.xml in the META_INF folder of my main app and it works great in the container (Glassfish). I placed a second persistence.xml in the META-INF folder of my test-classes directory. This contains a separate persistence unit that I want to use for test only. In eclipse, I placed this folder higher in the classpath than the default folder and it seems to work. Now when I run the maven build directly from the command line and it attempts to run the unit tests, the persistence.xml override is ignored. I can see the override in the META-INF folder of the maven generated test-classes directory and I expected the maven tests to use this file, but it isn't. My Spring test configuration overrides, achieved in a similar fashion are working. I'm confused at to whether the persistence.xml is located through the classpath. If it were, my override should work like the spring override since the maven surefire plugin explains "[The test class directory] will be included at the beginning the test classpath". Did I wrongly anticipate how the persistence.xml file is located? I could (and have) create a second persistence unit in the production persistence.xml file, but it feels dirty to place test configuration into this production file. Any other ideas on how to achieve my goal is welcome.

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  • Loopj Android Async Http - onFailure not fired

    - by Ashley Staggs
    I am using the great async http library from loopj, but I have run into a small snag. If the user has no internet connection or loses their connection, the app just won't return anything. This part is expected, but it also doesn't fire the onFailure method. Also, the code I have used when there is an internet connection does work so there is no problem on the server end. Here is some code that is stripped down to the minimum. It also doesn't work (I have tested this too) String url = getString(R.string.baseurl) + "/appconnect.php"; client.getHttpClient().getParams().setParameter(ClientPNames.ALLOW_CIRCULAR_REDIRECTS, true); client.get(url, null, new JsonHttpResponseHandler() { @Override public void onSuccess(JSONArray response) { Toast.makeText(getApplicationContext(), "Success", Toast.LENGTH_SHORT).show(); } @Override public void onFailure(Throwable e, JSONArray errorResponse) { Toast.makeText(getApplicationContext(), "Failure", Toast.LENGTH_SHORT).show(); } }); Thanks, Ashley

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