JSF :: Registering Model Services As ServletContext Attributes Using ServletContextListener
Aug 11, 2014
I am making an application in which I have to make the model (the services) available to the entire application so that all beans can access it and call its methods during the life of the application.
I am using the following technologies:
view: JSF 2.x
beans: Spring 4.x beans
The design problem I am having is the following:I came up with the idea of registering the model services as ServletContext attributes using my ServletContextListener, effectively making the services available to the entire application:
//imports
public class MyContextListener implements ServletContextListener {
//model services
private UserService userService;
private RepairService repairService;
public void initCafe()
{
userService.removeAllUsers();
repairService.removeAllRepairs();
[code]....
Shouldn't I just use @Autowired userService and @Autowired repairservice everywhere I want to use these services application-wide?Or is this a problem because beans have a default scope of Request? I am confused.
Why we need to use ServletContext attribute when we already have ServletContext parameters.Whats the difference between ServletContext Attributes and ServletContext parameters.
I have requirement, in that I am showing a Datatable, above that table i have form in that i can register a employee, after clicking on submit employee data have to be saved in the database aswell as i have to update datable, so that I can see that registered employee in that Datatable, how can i full fill this requirement. I am using jsf 2.0, ejb3.0,jpa 2.0.
In managed bean I am calling this service as fallow in init method, and i am binding same this. employee list to UI
public String getAllEmployeesfronHr() { this.employees = customerservice.getallEmployees(); System.out.println(this.employees.size() + "=================size of employee"); return ""; }
For every submit button click i have to query database or is there any mechanism to update List / can we use entity manager in anyway so that we can update Employee List....
I have two java classes, the first is a Servlet that register users access to the same servlet, the second class implements a ServletContextListener and update the HashMap removing the expired access.I need this Application to obtain a list of online users on an android app, this is the code:
How does the init() method in servlets have access to the servletContext . in its signature i can only see public void init(ServletConfig config) and init () . then how does it access servlet context .
i am newbie to servlet and m working on a project like online shopping. I have list of data items in my database and i am able to fetch and display the data from database but i want to know that how can i store these data items in ServletContext so that i can use use it frequently in other pages.
How can i use multiple textures on a model? I have the .OBJ loader and .MTL loader and everything is working fine. I can use a single texture. But i have a model that has 2 textures. How can i use both of the textures?
Boolean retrieval model using skiplist. I don't know how to code it. I have modified it but I'm not sure it work out. What are the modifications I can made.
/**My requirement is to implement two methods for Boolean Retrieval:
● index(String dir) ○ index()supposed to go over all files under "dir". There will be no subdirectories inside it.
● retrieve() ○ retrieve() supposed to return name of all the documents under "dir" that satisfies the given query. Note that, only basename of the files are to be returned, not the full path. ○ Query can be of two forms: ■ OR: returned doc should contain at least one term from the query. ■ AND: returned doc should contain all the terms from the query. **/
import java.util.HashSet; import java.util.Vector; public class BooleanRetrievalModel implements DocSearch { // begin private class private class SkipList { // Node in skip-list
I have some paired values stored as a hashmap in my model, for example sake, we'll say the 'key' is a Manager's ID and the 'value' is the name of their department, so 'betty123' could be a key to a value 'IT', and 'dave345' could be a key for the value 'Finance'. This hashmap is populated from a database. In my form, I have two "Select" dropdown fields, one for "Department" (with fields which match the values in the hashmap), and one for "Manager ID". I want to autopopulate the "Manager ID" field when the "Department" field is changed, based on the values in the Hashmap. I understand that I can't access dynamically elements of the hashmap in a script, so, for example, I can't do this:
var specificDepartment= $("#department"); var managerId = ${departmentHash[specificDepartment]}; $("#manager").val(managerId);
Because this code is dynamic based on the value of "department" at the time it's run, whereas the departmentHash object is generated when the page is loaded.
Is there some other way I can do this? Am I approaching it the wrong way? FWIW, I'm using Spring 4.1.1 and jQuery 1.8. I understand the conceptual block with code I wrote above, but I can't for the life of me think of an obvious solution although I'm sure this is a fairly commonplace problem in web development.
I understand how vectors work I'm currently using one to store my id's from my txt file but how do you put them in a defaultComboBoxModel?
DefaultComboBoxModel defaultComboBoxModel = new DefaultComboBoxModel(); //declare a vector object that will hold a string (only thing that works with comboboxmodel Vector<String> myVector=new Vector<String>(); //try statement try{ FileReader fr = new FileReader(file);
[Code]...
Any example of how a vector is used with a defaultComboBoxModel so I can then use that to populate my JComboBox?
I get the value from database and display in table , price value will show 6 decimal and date value will show date and time.What to do to show only 2 decimal places and only date e.g. 1/1/2014 in the table ?
When one is needed I simply add it to the table. In this case however whilst updating the model via table update in tableChanged method I have the impression of 2 identical models because the update happens twice (use of audio).
Is it not true that adding a new model cancels out the other ? I test for which model is attached to table and add the correct one depending on the data required.
/* * * You need to implement BooleanRetrievalModel using SkipList. * You should have everything within this file. */
import java.util.HashSet; import java.util.Vector; public class BooleanRetrievalModel implements DocSearch { // begin private class private class SkipList { // Node in skip-list
I am working on an project in which some data needs to be received through socket , do some processing on it and then store on the database. After that it will display on GUI. GUI should be updated automatically.
I am able to implement basic model in which data is storing in the database and displayed then on the GUI. I tried to implement MVC design patter as well.
Now i need to create a GUI which can be used by several users at a time means several jvm session for the GUI. I got struck at this point.
Some detail: i have one jvm session in which i am receiving , processing and storing the data. Now i want to fire an alert whenever any new entry is made into the database. Also each time new GUI is opened it should be registered with the model so that model send updated data alert to all this users.
When i am trying to open several GUI and trying to register with the Model then it is not increasing count of registered user. For each time it is showing 1 count only and whenever a new entry is made count is showing 0. Is it because both are running in different jvm sessions ?
Some code for the model which is running in different package and jvm
GUI..
private void runApp() { //some gui code WindowListenerClass windowListener = new WindowListenerClass(this); frame.addWindowListener(windowListener) //registering viewer with the model Model.setNewAlarmEvent(this); tableModel = windowListener.getDefaultTableModel();
I'd like to create my own Table Model to handle data from an SQLite database using JSwing, but I'm having difficulty. How to confirm the following:
-- A table model is an object that contains methods for manipulating data in the table, right?
If that's the case, then how should I create a Table Model to handle data coming from a database. From what I understand...
My custom Table Model needs to subclass AbstractTableModelI then override 3 methods from AbstractTableModel (getRowCount(), getColumnCount(), getValueAt())
As it relates to drawing data from a database, how should I be thinking about this problem (i.e. creating a Table Model that can work with a database)?
I am trying to model a galaxy so that I have multiple stars certain distances away from each other and with different masses.
The accretion and than cylinder expansion happens with just about every galaxy.
I have a few questions.
First My computer only runs this if the number of particles is in the 500s. If that's the case How can I increase the probability that I will when I get to it have a red giant?
Second how can I modify this so that I have a timescale during which white dwarfs form from some stars and you see in the single stars either no supernova or nova just degeneration or a type 2 supernova and in binaries a type 1a supernova which is like a type 2 supernova of 1 star when it is a red giant, that giant becoming a white dwarf, the other star becoming a red giant, and then the white dwarf sucking gas from the giant until it explodes and ejects its companion?
Third how can I make this compacted and taking up less space in case I want to expand it to a few galaxies or even start with a big bang?
Basically what I am asking is how can I make this like a universe?
I have a requirement where we have an ETL jobs that runs in the backend which will get the up to date data from various sources , here we have both structured and unstructured data and the data capacity is massive which is in petabytes. Based on the data that is fetched we need to come up with a consolidated data view for the data which we retrieved. My queries are:-
1) How to create a consolidate data view , in what form it will be in (XML, JSON, etc)? whether we need to come up with a unified data model as the data is both structured and unstructured format? If so how we can go about it?
2) Since the data is really massive, how we can construct the consolidate data view? whether we need to create it in small chunks or whether we need to store these data in a cache or DB from where we will retrieve it and form the consolidated data view?
3) To process these data whether we need to have any Hadoop clusters to process these data parallel? As we are talking about massive data in the form of structured and un structured format?
4) Whether there is a need for NoSQL database to support unstructured data? If we are supposed to store the data?
I have tried to implement MultipleSelectionModel with mostly success in TreeView, but definitely with quirks. I've looked at the implementation in TreeView and it's off putting to say the least. Hopefully it doesn't need to be that complicated. For now, all I need is it to handle SINGLE SELECTION, but it needs to be solid. I've put in a lot of println's to see what gets called. Most don't seem to be called. I'm relying on TreeView to look up the object being selected, I'm not sure if that's appropriate. The internal implementation seems to worry about tree state a lot.
It baffles me as to why there isn't a base class from which to extend or reuse? I'm doing this so I can delay a selection (make it vetoable), also to handle drag/drop more cleanly (so target won't move because of drag action).
private class VSelectionModel extends MultipleSelectionModel { List<Integer> baseSelectedIndexes = new ArrayList<>(); ObservableList<Integer> selectedIndexes = FXCollections.observableList(baseSelectedIndexes); List<Object> baseItems = new ArrayList<>(); ObservableList items = FXCollections.observableList(baseItems);
I have seen in some examples like URL... a good design is to have the model and the action methods in one just single bean and the model not to be a separated class but a few properties like this:
public class CustomerBean implements Serializable{ //DI via Spring CustomerBo customerBo; [b]public String name;[/b] [b]public String address;[/b] //getter and setter methods
[code]...
Some questions:
1. If you are using hibernate or any other ORM like the above example(URL...), why not to use the hibernate pojo bean directly like it represented the form instead of using properties?:
public class CustomerBean implements Serializable{ //DI via Spring CustomerBo customerBo; [b]Customer customer;[/b] //represents the properties of a form //getter and setter methods public void setCustomerBo(CustomerBo customerBo) { this.custom
2. Why is it said that JSF represents the purest MVC? Spring separates the model from the view too and Struts does too. I dont really understand it
This is a design question is the same problem in any language.as you do to map the controller to the domain model?We have situations in general larger than ... consider the example objects .
situation.1 - We have a request that has all the parameters of the account ;{ " id" : " 1 " , "name " : "test " , "some " : " xxx " } ............. and other fields .
situation.2 - can request that has to have a certain account parameters , for example in the case of an update;{" id" , " 1" , "name " , " testUpdated "}
situation.3 - We have a request that has some parameters of the account , others have more like id as user together;{ " id" : " 1 " , "user " : " xxx " , "service " : " yyy " } in which case each piece of the request will turn an object .
Java Code:
public class Account {
private Long id; private String name ; private String some ;
} mh_sh_highlight_all('java');
I see a few options ;
1 - Can I get AccountForm in the controller and set the properties for the Account object and others in CONTROLLER ;
+ ok for situation.1 situations 2, and situation.3
+ Separates the requisition of the object domain
- Pollutes the controller with code conversion
- Controller is full of setters .. if a higher class as a large object as a request is very confusing .
Java Code:
controller ( AccountForm from ) { Account account = new Account ( ) account.setNome form.getNome = (); account.setSome form.getSome = (); Other outher = new Other ( ) ; other.setSome ( form.getSome ( ) ) ; } mh_sh_highlight_all('java');
2 - Can I get AccountRequest in the controller and have a method in itself as AccountRequest.getAccount ( ) to return a mapped model , in this case the mapping is at own Request object .
+ Separates the requisition of the object domain
+ Encapsulates the conversion in a place with easy access .
+ Meets situation.1 situation.2 and situation3 ;
- Request object has two responsibilities represent the request and map to a valid model .
4 - Outsource this mapping request parameters to another object mapper for request ..
+ Isolates logic mapping
- Until complexity for simpler cases are used as standard for all such a find by id .
- One more class for each request ;
In the case of API gets worse response has two further classes. speaking in terms of request for response .... AccountRequest, AccountRequestMapper, Account, AccountResponseMapper, AccountResponse .....I'm doing more testing the Hybrid option 3 for simple cases (find ID or updates) .... with option 2 for example for more complex cases ..
I'm attempting to make a model of the solar system. Up till now, I have a Sun and the Earth revolving around it. The problem I have is when I add inheritance to the program. The moon that I created does not orbit the Earth.
Here's my code for the classes I've created
public class Driver { public static void main(String[] args){ SolarSystem model = new SolarSystem(700, 700); /* Create new instances of each object in the solar system */ SunObject sun = new SunObject(); PlanetObject earth = new PlanetObject(140, 30, 15, "BLUE", 2); MoonObject moon = new MoonObject(15, 30, 2, "WHITE", 1.5);
[Code] ....
Note that SolarSystem is a class given to me. That contains all the paint methods. I'm just creating new instances with the drawSolarObject()
And the drawSolarObjectAbout takes an extra two parameters:
centreOfRotationDistance - the distance part of the polar co-ordinate about which this object orbits. centreOfRotationAngle - the angular part of the polar co-ordinate about which this object orbits
And a MoonObject class, which is EXACTLY the same as the PlanetObject class. The main problem I'm having is when I extend my PlanetObject class to a PointInSpace class below:
public class PointInSpace { private double distance; private double angle; public double getPointDistance(){ return distance;
[Code] .....
What I'm trying to do is use the distance and angle in the PointInSpace class so that my Moon can orbit those two coordinates . I get it working when I method override when drawing the moon - using earth.getDistance() instead of earth.getPointDistance() etc. Have I inherited properly? Should I try a method overloading process instead?
I have been going in circles trying to update a JTable. For now I just need to take input from a textfield after clicking on a JButton and have that text be placed in the JTable. LeftPanel listens, while RightPanel holds the table. Here is what I have so far:
Sometimes models needs to access blocking devices, like network cards, databases, files, and so on. This should be done by worker threads or services. But who is in charge of that? The controller or the model itself? I tend to say it is the model, as only the model knows about the fact that it accesses a blocking object. On the other hand, it is said that a model should be a POJO, so it would be the controller's job. Is there a best practice or general design rule?
