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JSF
Oloks Ridwan
Quiz von Oloks Ridwan, aktualisiert more than 1 year ago
Oloks Ridwan
Erstellt von Oloks Ridwan vor mehr als 9 Jahre
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Zusammenfassung der Ressource

Frage 1

Frage
What is a principal?
Antworten
  • represents an (authenticated) user
  • represents

Frage 2

Frage
What is a role?
Antworten
  • group of principals who share common set of permissions
  • group

Frage 3

Frage
What annotations can be used to specify security privileges?
Antworten
  • @PermitAll @DenyAll @RolesAllowed @DeclareRoles @RunAs
  • @PermitAll

Frage 4

Frage
What is the difference between container-managed and application-managed security? What are the pros and cons of each? When might you choose to use one in preference to the other?
Antworten
  • Pros and cons of application-managed security Pro: complete control Pro: can fine-tune for performance Con: you might forget to put it in a method Con: managing site-wide may be a problem
  • Pros and cons of application-managed security

Frage 5

Frage
What is a native query?
Antworten
  • Native Queries are a concise and type-safe way to express queries directly as Java method.
  • Java Method

Frage 6

Frage
Why is using a named query often more efficient than a JPQL query?
Antworten
  • Using named queries may improve code organisation by separating the JPQL query strings from the Java code. It also enforces the use of query parameters rather than embedding literals dynamically into the query string and results in more efficient queries.
  • Using named queries may improve code organisation

Frage 7

Frage
Why is using a named query often more efficient than a JPQL query?
Antworten
  • Using named queries may improve code organization by separating the JPQL query strings from the Java code. It also enforces the use of query parameters rather than embedding literals dynamically into the query string and results in more efficient queries.
  • test

Frage 8

Frage
What is the JPA implementation that we use called? What other implementations are there?
Antworten
  • Hibernate, Toplink, we use this for JPA implementation in our coursework OpenJPA
  • Toplink, we use this for JPA implementation in our coursework

Frage 9

Frage
What are the pros and cons of using JPQL queries and criteria queries?
Antworten
  • JPQL queries are defined as strings, similarly to SQL. JPA criteria queries, on the other hand, are defined by instantiation of Java objects that represent query elements. Advantage of using the criteria API is that errors can be detected earlier, during compilation rather than at runtime. On the other hand, for many developers string based JPQL queries, which are very similar to SQL queries, are easier to use and understand. For simple static queries - string based JPQL queries may be preferred. For dynamic queries that are built at runtime - the criteria API may be preferred. It is cleaner when using the JPA criteria API, because it eliminates the need for building the query using many string concatenation operations.
  • need for building the query using many string concatenation operations.

Frage 10

Frage
What is a native query?
Antworten
  • Native Queries are a concise and type-safe way to express queries directly as Java method.
  • Java method.

Frage 11

Frage
What is the difference between optimistic and pessimistic transaction locking? Which do we normally use?
Antworten
  • Optimistic locking is applied on transaction commit. Any database object that has to be updated or deleted is checked
  • Any database object that has to be updated or deleted is checked

Frage 12

Frage
What is the relationship between a persistence unit and an entity manager?
Antworten
  • A persistence unit defines a set of all entity classes that are managed by EntityManager While The EntityManager is the primary interface used by application developers to interact with the JPA runtime
  • A persistence unit defines a set of all entity classes that are managed by EntityManager

Frage 13

Frage
What is a persistence unit and where are its details usually to be found?
Antworten
  • A persistence-unit provides a convenient way of specifying a set of metadata files, and classes, and jars that contain all classes to be persisted in a grouping. To define a persistence-unit you first need to add a file persistence.xml to the META-INF/ directory of your application jar. http://www.datanucleus.org/products/datanucleus/jpa/emf.html#persistenceunit
  • A persistence-unit provides a convenient way of specifying a set of metadata files, and classes, and jars that contain all classes to be persisted in a grouping.

Frage 14

Frage
What is a data access object used for?
Antworten
  • The Data Access Object is basically an object or an interface that provides access to an underlying database or any other persistence storage.
  • any other persistence storage.

Frage 15

Frage
What is a named query and what is it useful for?
Antworten
  • A named query is a statically defined query with a predefined unchangeable query string.
  • A named query

Frage 16

Frage
What major effort does JPQL save in comparison with SQL?
Antworten
  • The main difference between JPQL and SQL lies in that the former deals with JPA entities, while the latter deals directly with relational data. As a Java developer, you also maybe interested to learn that using JPQL, unlike SQL/JDBC, eliminates the need for you to use JDBC API from your Java code—the container does all this work for you behind the scenes.
  • The main

Frage 17

Frage
What is JPQL?
Antworten
  • The Java Persistence Query Language (JPQL) is a platform-independent object-oriented query language defined as part of the Java Persistence API (JPA) specification. JPQL is used to make queries against entities stored in a relational database.
  • The Java Persistence Query Language (

Frage 18

Frage
Why is JPQL useful?
Antworten
  • It is platform-independent.
  • its

Frage 19

Frage
What do we mean when we say that an entity is detached?
Antworten
  • A detached entity is an entity which state must not be reflected by the JPA provider. In other words, if you change its state (i.e. through setters methods) these changes will not be saved to the underlying database, as the JPA provider doesn't have to "observe" such entities.
  • A detached entity is an entity which state must not be reflected by the JPA provider.

Frage 20

Frage
How do you obtain an entitymanager when operating in each environment
Antworten
  • A container-managed entity manager is obtained in an application through dependency injection or through JNDI lookup. A container-managed entity manager requires the use of a JTA transaction. An Application managed entity manager is retrieved through the EntityManagerFactory API.
  • A container-managed entity manager is obtained in an application through dependency injection or through JNDI lookup

Frage 21

Frage
What is an entity manager?
Antworten
  • The EntityManager is the primary interface used by application developers to interact with the JPA runtime. The methods of the EntityManager can be divided into the following functional categories: • Transaction association. • Entity lifecycle management. • Entity identity management. • Cache management. • Query factory. • Closing.
  • • Closing.

Frage 22

Frage
Which relationships are by default eager, and which are by default lazy?
Antworten
  • one to one → eager many to many → lazy
  • one to one → eager

Frage 23

Frage
What strategies are available for mapping inheritance relationships in JPA?we have
Antworten
  • 3 a InheritanceType.SINGLE_TABLE - b InheritanceType.TABLE_PER_CLASS c InheritanceType.JOINED
  • a InheritanceType.SINGLE_TABLE -

Frage 24

Frage
What do the terms eager and lazy mean in this context?
Antworten
  • It gives a hint to the persistence provider runtime that data should be fetched lazily (only when the application asks for the property) or eagerly (when the entity is initially loaded by the provider).
  • the entity is initially loaded by the provider).

Frage 25

Frage
How do you tell JPA where to store the data that makes up a foreign key? [Be careful!]
Antworten
  • @OneToOne @JoinColumn(name="parent_id", referencedColumnName="ID") private Parent parent; }
  • (name="parent_id", referencedColumnName="ID") private Parent parent; }

Frage 26

Frage
Explain what an HTTP request is
Antworten
  • it is a message from client to server requesting resources
  • requesting resources

Frage 27

Frage
How does an HTTP request travel over a network?
Antworten
  • it is traveling through TCPIP protocol
  • protocol

Frage 28

Frage
Explain what an HTTP response is and its relationship to a request
Antworten
  • It is the message from the server to the client as per the request sent from the client to server.
  • from the client to server.

Frage 29

Frage
Explain what HTTP status codes such as 200 and 404 mean
Antworten
  • 404 code is the status code from the server to the client indicating the resource not found. 200 it is the code from server to client indicating that the request is received successful
  • request is received successful

Frage 30

Frage
What is a mime type and what is its relationship to HTTP messages?
Antworten
  • Multipurpose Internet Mail Extension. The relation between the HTTP and MIME type is MIMIE type is part of HTTP header response
  • The relation between the HTTP and MIME type is MIMIE type is part of HTTP header response

Frage 31

Frage
Why in the WWW might there be more HTTP requests than HTTP responses?
Antworten
  • Because the request might not reach to the server because of network error. or might be the server is switched off.
  • switched off.

Frage 32

Frage
What is the difference between a static web page and a dynamic one?
Antworten
  • Developers generally create static pages with HTML, but use languages like PHP, Javascript, or Actionscript to create dynamic pages. They can also use frameworks like Ruby on Rails, Django, or Flex for dynamic pages. Dynamic languages and frameworks also have the technical capacity to create static Web page content. However, doing so creates source code that is unnecessarily complex for its purpose while being more difficult to maintain
  • html

Frage 33

Frage
How does the content of a dynamic web page get created?
Antworten
  • PHP, Javascript, or Actionscript
  • a

Frage 34

Frage
What are the four architectures for dynamic web applications?
Antworten
  • CGI, server side include, server module and auxiliary server
  • auxiliary server

Frage 35

Frage
Why is the architecture that Java uses the most scalable?
Antworten
  • By adding more auxiliary server
  • by adding more auxiliary server

Frage 36

Frage
Why is the architecture that Java uses the most resilient?
Antworten
  • high availability, fault tolerance
  • ssss

Frage 37

Frage
How can you use Java's architecture to provide an enterprise web application on a global scale
Antworten
  • by adding more web servers and auxiliary server
  • auxiliary server

Frage 38

Frage
What is a servlet?
Antworten
  • min program receive the request from the client and map it to functionality
  • functionality

Frage 39

Frage
What is a JSP?
Antworten
  • java web programming get translated to servlet once received by servlet engine
  • servlet engine

Frage 40

Frage
What is the relationship between a JSP and a servlet?
Antworten
  • JSP is a servlet
  • servlet

Frage 41

Frage
What advantages does Java's servlet programming model have over (a) CGI? (b) PHP?
Antworten
  • threading and at each time CGI has to run a program which is not good practice for OS. The problem of php is in case the module is crashed than the web server is also down
  • The problem of php is in case the module is crashed than the web server is also down

Frage 42

Frage
What is an exception and what is one used for?
Antworten
  • it is used to reporting the error.( exception is an event which occur during the execution of a program, that disrupts the normal flow of the program instructions.
  • ( exception is an event which occur during the execution of a program, that disrupts the normal flow of the program instructions.

Frage 43

Frage
Explain throwing and catching exceptions?
Antworten
  • Creating an object and handing it to the runtime system is called throwing exception. The exception handler chosen is said to catch the exception.
  • Creating an object

Frage 44

Frage
What do we mean when we say that one class inherits from another?
Antworten
  • It is the mechanism where in a new class is derived from existing class. class may inherit or acquire the properties and methods of other class.
  • It is the mechanism where in

Frage 45

Frage
If an application had classes Person, StaffMember and Student, how might they be related?
Antworten
  • StaffMember and Student are sub class of Person
  • Person

Frage 46

Frage
java.util and jim.sums.entities are examples of what?
Antworten
  • packages
  • p

Frage 47

Frage
What is the difference between a field that is private, protected or public?
Antworten
  • Private:- filed it can be use within the class and it can not be used outside the class protected:- visible only to the class where it is declared and to subclasses public:- it is visible to all class, subclass and packages
  • packages

Frage 48

Frage
What does static mean when associated with a class's fields or methods? it is a variable which is not changed wherever it called or used
Antworten
  • it is a variable which is not changed wherever it called or used
  • used

Frage 49

Frage
Explain what the classes/interfaces Collection, Set, List, ArrayList and Vector represent and what are the distinctions between them?
Antworten
  • A Collection represents a group of objects known as its elements. The Collection interface is used to pass around collections of objects where maximum generality is desired. A Set is a Collection that cannot contain duplicate elements. A List is an ordered Collection (sometimes called a sequence). Lists may contain duplicate elements. Array List:- general purpose implementation list which is usually the best performing implementation
  • e

Frage 50

Frage
What is a Map
Antworten
  • A Map is an object that maps keys to values
  • values

Frage 51

Frage
What does the declaration Map<String, Person> represent?
Antworten
  • mapping from string to person
  • w

Frage 52

Frage
What is a facelet?
Antworten
  • it is part of java server written in xml
  • xml

Frage 53

Frage
What is a managed bean?
Antworten
  • it is a class with constructor and getter and setter. Also it is JSF controller
  • Also it is JSF controller

Frage 54

Frage
What is meant by the scope of a managed bean?
Antworten
  • it is mean the lifetime of the object
  • lifetime of the object

Frage 55

Frage
What are the available scopes to choose from?
Antworten
  • Session scope:- (session end when its timeout) Request scope:- start when request started and end after request is received Application scope:- View scope:-
  • start when request

Frage 56

Frage
Which scope is the default?
Antworten
  • in JAVA EE6 is request scope, in JAVA EE7 is non scoped
  • JAVA EE6

Frage 57

Frage
Give at least 10 examples of how different HTML controls can be represented using facelet tags
Antworten
  • h:inputText , h:inputHidden, h:inputSecret, h:inputTextarea, h:link, h:commandButton, h:button, h:form, h:panelGrid , h:dataTable
  • h:inputText

Frage 58

Frage
What do the properties of a managed bean represent?
Antworten
  • the data which can be share between view and controller
  • controller

Frage 59

Frage
What notation is used in a facelet to associate a property or method with a control?
Antworten
  • expression language #
  • &&

Frage 60

Frage
Why is JSF superior to JSP?
Antworten
  • jsp is not supported MVC pattern fully, while jsf is fully supported for JSF
  • upported for JSF

Frage 61

Frage
What are the 3 types of session bean?
Antworten
  • stateless, stateful and Singleton
  • Singleton

Frage 62

Frage
In what circumstances would you use each of the 3 types?
Antworten
  • stateful: The bean needs to hold information about the client across method invocations. stateless:- The bean’s state has no data for a specific client. Singleton:-State needs to be shared across the application.
  • Singleton:-State needs to be shared across the application.

Frage 63

Frage
Which of the 3 types is most commonly used?
Antworten
  • stateless
  • l

Frage 64

Frage
What is the difference between a session bean and a message bean?
Antworten
  • message bean used to deal with messages while session beans used in business logic to interact with database
  • database

Frage 65

Frage
What is dependency injection?
Antworten
  • Dependency injection (DI) is the concept of providing an external dependency to a specific resource, generally by a Java EE container It enables you to provide a set of services to Java EE components
  • Java EE components

Frage 66

Frage
Who or what does the injecting?
Antworten
  • Who=java EE container, what= @EJB
  • ll

Frage 67

Frage
What annotation is normally used for dependency injection?
Antworten
  • @EJB
  • l

Frage 68

Frage
How would you specify the start and end of a transaction in a stateful EJB? BY using
Antworten
  • @REMOVE annotation
  • @REMOVE annotationl

Frage 69

Frage
What annotations can be used to control what happens when an EJB is created or destroyed? @PreDestroy @PostConstruct
Antworten
  • destroyed? @PreDestroy @PostConstruct
  • @PostConstruct

Frage 70

Frage
What is the timer service used for?
Antworten
  • Enables you to schedule timed notifications for all types of enterprise beans except for stateful session beans. You can schedule a timed notification to occur according to a calendar schedule, at a specific time, after a duration of time, or at timed. How to use it? intervals.timerService.createSingleActionTimer(duration, new TimerConfig());
  • TimerConfig());

Frage 71

Frage
What is the difference between a local interface, a remote interface and a no-interface view?
Antworten
  • When EJB does not explicitly specify as interface type it is assume to be local otherwise it is remote. @localBean @remoteBean No -Interface :Is almost same as local client view, but there are differences. Your bean class is not required to implement client view interfaces in this case. All public methods of the bean class are automatically exposed to the caller. no-interface view always acquires an EJB reference
  • l

Frage 72

Frage
What do we mean by pooling beans?
Antworten
  • There's a limited number of beans in a pool and the container picks instances from the pool to serve requests as they come.
  • picks instances from the pool to serve requests as they come.

Frage 73

Frage
What is an entity bean?
Antworten
  • Mapping object to database, representing business object
  • object

Frage 74

Frage
How do you make a bean an entity bean?
Antworten
  • @enitity annotation
  • by

Frage 75

Frage
What does the @Id annotation do?
Antworten
  • is the annotation used to specify primary key
  • primary key

Frage 76

Frage
What annotation is used to denote a composite primary key?
Antworten
  • @embeddedID
  • @

Frage 77

Frage
Under what particular circumstances would you have to use the @Column and/or @Table annotations?
Antworten
  • when the database column not match the entity class column
  • entity class column

Frage 78

Frage
Explain what is meant by a unidirectional relationship and a bidirectional relationship?
Antworten
  • In a unidirectional relationship, only one entity has a relationship field or property that refers to the other. For example, LineItem would have a relationship field that identifies Product, but Product would not have a relationship field or property for LineItem. In other words,LineItem knows about Product, but Product doesn’t know which LineItem instances refer to it. while in a bidirectional relationship, each entity has a relationship field or property that refers to the other entity. Through the relationship field or property, an entity class’s code can access its related object. If an entity has a related field, the entity is said to “know” about its related object. For example, if Order knows what LineItem instances it has and if LineItem knows what Order it belongs to, they have a bidirectional relationship.
  • relationship,

Frage 79

Frage
What are the annotations used to specify the chosen inheritance strategy? Where must those annotations be placed?
Antworten
  • @inheritence Before the constructor class.
  • constructor class.

Frage 80

Frage
How do you get JPA to arrange your lists in the right order?
Antworten
  • @orderBySource
  • Source
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