{"id":67690,"date":"2021-07-27T04:10:07","date_gmt":"2021-07-27T08:10:07","guid":{"rendered":"http:\/\/bangla.salearningschool.com\/recent-posts\/basic-java-but-essential-knowledge-for-exams-like-scja-or-to-the-project-managers-new-to-java-technologies-computer-game-design-java-short-notes\/"},"modified":"2021-07-27T04:10:07","modified_gmt":"2021-07-27T08:10:07","slug":"basic-java-but-essential-knowledge-for-exams-like-scja-or-to-the-project-managers-new-to-java-technologies-computer-game-design-java-short-notes","status":"publish","type":"post","link":"http:\/\/bangla.sitestree.com\/?p=67690","title":{"rendered":"Basic Java But Essential Knowledge for exams like SCJA, or to the project managers new to Java technologies #Computer Game Design #Java Short Notes"},"content":{"rendered":"<ul>\n<li>By definition an enumerated type is a finite set of symbolic literals<\/li>\n<li>In Java an enumerated type is represented as first-class object.<\/li>\n<li>Enumerated type literals are allowed in case statements.<\/li>\n<li>The literals of an enumerated type may be of any valid Java identifier<\/li>\n<li>An interface may NOT contain any concrete method implementations<\/li>\n<li>An interface is NOT a class of any style.<\/li>\n<li>An interface defines a set of abstract methods that may have many implementations.<\/li>\n<li>An interface is NOT a member of a class.<\/li>\n<li>Both class associations and class compositions relationship may be of any multiplicity.<\/li>\n<li>compositions may also have navigation methods, but these methods must NOT pass references to the owned objects. This is usually achieved by passing back a copy of the object rather than the owned object itself. Composition implies that the owning object controls the life cycle of the owned object.<\/li>\n<li>Dependency:one object uses another object during computations.<\/li>\n<li>the portability of a Java application is NOT dependent<\/li>\n<li>upon whether information hiding was used. the class cannot protect bad assignments. For example, setting a negative value for an account balance.<\/li>\n<li>classes that do NOT support information hiding are NOT treated specially in Java<\/li>\n<li>Disadvantages of information hiding: Access to object<\/li>\n<li>attributes incur a runtime penalty.However, the Sun hotspot JVM usually can eliminate the added overhead by &#8220;inlining&#8221; the methods where they are called.<\/li>\n<li>It is time consuming to use methods to access object attributes rather than direct access.<\/li>\n<li>Information hiding does NOT restrict the reusability of a superclass.<\/li>\n<li>Interfaces are only contracts (declarations of public methods) and a program needs classes for actual behavior.<\/li>\n<li>NOT every class will have behavior that requires an explicit contract (interface).<\/li>\n<li>It is the reference variables to objects that need to be as generic as possible. This is the essence of the &#8220;program to an interface&#8221; principle.<\/li>\n<li>An interface cannot be instantiated using the new operator<\/li>\n<li>The minus symbol in a uml class diagram signifies private visibility<\/li>\n<li>the + symbol in a uml class diagram signifies public visibility<\/li>\n<li>encapsulation: all of its attributes be private and it provides appropriate public accessor and mutator methods.<\/li>\n<li>UML: attribute representation: &#8211; attr : int<\/li>\n<li>UML\n<ul>\n<li>? is NOT a valid multiplicity indicator.<\/li>\n<li>0..* indicates zero or more multiplicity.<\/li>\n<li>0..1 indicates zero or one multiplicity, which is how you can represent an optional association.<\/li>\n<li>?..1 is NOT a valid multiplicity indicator.<\/li>\n<li>? is NOT a valid multiplicity indicator.<\/li>\n<li>* is an abbreviation for 0..*.<\/li>\n<li>M is NOT a valid multiplicity indicator.<\/li>\n<li>? is NOT a valid multiplicity indicator.<\/li>\n<li>0..* is exactly how to indicate zero or more.<\/li>\n<li>M is NOT a valid multiplicity indicator.<\/li>\n<\/ul>\n<\/li>\n<li>Enums and arrays make use of object references<\/li>\n<li>A source file can have zero package statements or one package statement.<\/li>\n<li>A source file automatically imports all classes of its package.<\/li>\n<li>java -version com.example.MyProgram: The Java interpreter prints the version information and exits.<\/li>\n<li>The Collections APIs contain interfaces for lists and sets.<\/li>\n<li>The Collections APIs are in the java.util package.<\/li>\n<li>the classes for TCP and UDP communication are contained in the java.net package.<\/li>\n<li>cell phone side of an application requires the micro edition and the server side with EJB requires the enterprise edition<\/li>\n<li>the J2SE platform has rich GUI capabilities, as well as IP communication capabilities allowing multiple, Internet-wide applications to exchange data.<\/li>\n<li>TCP\/IP sockets are the basis of RMI.<\/li>\n<li>RMI may create new threads for each request.<\/li>\n<li>JMS is used to communicate with messaging services asynchronously.<\/li>\n<li>HTML does NOT provide interactive capabilities.<\/li>\n<li>HTML does NOT provide a rich set of UI components.<\/li>\n<li>HTML does provide navigation capabilities, such as hyperlinks.<\/li>\n<li>HTML does provide rich text formatting capabilities, such as tables and cascading style sheets.<\/li>\n<li>J2me include APIs for playing audio media.<\/li>\n<li>J2ME provides limited user interface components.<\/li>\n<li>J2ME applications usually execute on small devices with small screen resolution, which cannot support rich UI components.<\/li>\n<li>an Applet executes within a security sandbox that, by default, prohibits access to the user&#8217;s filesystem.<\/li>\n<li>an Applet might fail to execute correctly (or at all) if the web browser does NOT have the appropriate JRE installed.<\/li>\n<li>an Applet does NOT have access to the web browser&#8217;s cookie information.<\/li>\n<li>the default security sandbox does permit communication with the originating enterprise server.<\/li>\n<li>Applets execute in a security sandbox that does NOT permit access to files on the client system.<\/li>\n<li>Applets can be used to create animated games. However, Applets do NOT have access to gaming-specific APIs like J2ME applications do.<\/li>\n<li>Applets cannot connect to arbitrary Internet servers.<\/li>\n<li>Applets may connect to the server that delivered the Applet to access media files on that server.<\/li>\n<li>Applets can access other Applets on the same web page.<\/li>\n<li>Applets can access other Applets on the page through the AppletContext object supplied by the web browser.<\/li>\n<li>Swing (Richest GUI components in j2SE) has a broader GUI component set than AWT.<\/li>\n<li>MIDP is a J2ME (not J2SE) profile.<\/li>\n<li>JSF is a J2EE web-based UI component framework with only a limited component set.<\/li>\n<li>AWT has a more limited GUI component set than Swing<\/li>\n<li>SWT is NOT a standard J2SE technology.<\/li>\n<li>JSP is used to create dynamic HTML content. It does NOT handle business logic.<\/li>\n<li>JMS is the technology that handles asynchronous requests and performs the business logic of these requests.<\/li>\n<li>JDBC is a database communication technology and does NOT handle business logic.<\/li>\n<li>JNDI is a naming and directory service interface. It does NOT handle business logic.<\/li>\n<li>JNDI and JDBC support completely independent purposes in an application. JNDI is an interface to directory servers and JDBC is an interface to database servers.<\/li>\n<li>servlets and SQL support completely independent purposes in an application. Servlets respond to HTTP requests and SQL is used to communicate with relational databases.<\/li>\n<li>JavaMail uses SMTP (simple mail transfer protocol), which is used to send email from an application to users.<\/li>\n<li>JavaScript and EJB support completely independent purposes in an application. JavaScript provides interactivity to web pages and Enterprise JavaBeans provide business logic.<\/li>\n<li>JSP technology simplifies the creation of dynamic web pages.<\/li>\n<li>JSP technology is a server-side technology.<\/li>\n<li>JSP technology is NOT intended to be used to create business components.<\/li>\n<li>JSP technology is ideal for web designers who are NOT familiar with Java programming.<\/li>\n<li>JSP technology is NOT an integration technology.<\/li>\n<li>JSP is NOT an EJB technology<\/li>\n<li>servlets are NOT an EJB technology<\/li>\n<li>MDBs do NOT record client conversational state<\/li>\n<li>stateful session beans are used to record client conversational state<\/li>\n<li>stateless session beans do NOT record client conversational state<\/li>\n<li>entity beans are used to represent persistent data.<\/li>\n<li>message-driven beans handle asynchronous events.<\/li>\n<li>Session beans only handle synchronous events.<\/li>\n<li>session beans represent business processes and<\/li>\n<li>stateless session beans are client-independent. That is, they do NOT store conversational state.<\/li>\n<li>session beans do NOT exist in the web container<\/li>\n<li>stateless session beans are used to represent client-independent business processes.<\/li>\n<li>J2EE provides a rich and flexible programming model, but it is NOT simple<\/li>\n<li>J2EE infrastructure provides rich concurrency support in both the web and EJB tiers, which supports highly scalable application development.<\/li>\n<li>clustering is NOT directly supported by the J2EE specification. However, most vendor implementations of J2EE do support clustering.<\/li>\n<li>J2EE provides declarative transaction management.<\/li>\n<li>declarative transaction management is a required feature of the EJB container<\/li>\n<li>declarative user interface construction &#8211; is NOT part of the J2EE specification.<\/li>\n<\/ul>\n<p> From: http:\/\/sitestree.com\/?p=4909<br \/> Categories:Computer Game Design, Java Short Notes<br \/>Tags:<br \/> Post Data:2007-09-02 02:28:37<\/p>\n<p>\t\tShop Online: <a href='https:\/\/www.ShopForSoul.com\/' target='new' rel=\"noopener\">https:\/\/www.ShopForSoul.com\/<\/a><br \/>\n\t\t(Big Data, Cloud, Security, Machine Learning): Courses: <a href='http:\/\/Training.SitesTree.com' target='new' rel=\"noopener\"> http:\/\/Training.SitesTree.com<\/a><br \/>\n\t\tIn Bengali: <a href='http:\/\/Bangla.SaLearningSchool.com' target='new' rel=\"noopener\">http:\/\/Bangla.SaLearningSchool.com<\/a><br \/>\n\t\t<a href='http:\/\/SitesTree.com' target='new' rel=\"noopener\">http:\/\/SitesTree.com<\/a><br \/>\n\t\t8112223 Canada Inc.\/JustEtc: <a href='http:\/\/JustEtc.net' target='new' rel=\"noopener\">http:\/\/JustEtc.net (Software\/Web\/Mobile\/Big-Data\/Machine Learning) <\/a><br \/>\n\t\tShop Online: <a href='https:\/\/www.ShopForSoul.com'> https:\/\/www.ShopForSoul.com\/<\/a><br \/>\n\t\tMedium: <a href='https:\/\/medium.com\/@SayedAhmedCanada' target='new' rel=\"noopener\"> https:\/\/medium.com\/@SayedAhmedCanada <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>By definition an enumerated type is a finite set of symbolic literals In Java an enumerated type is represented as first-class object. Enumerated type literals are allowed in case statements. The literals of an enumerated type may be of any valid Java identifier An interface may NOT contain any concrete method implementations An interface is &hellip; <\/p>\n<p><a class=\"more-link btn\" href=\"http:\/\/bangla.sitestree.com\/?p=67690\">Continue reading<\/a><\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1917],"tags":[],"class_list":["post-67690","post","type-post","status-publish","format-standard","hentry","category-fromsitestree-com","item-wrap"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":67688,"url":"http:\/\/bangla.sitestree.com\/?p=67688","url_meta":{"origin":67690,"position":0},"title":"Java: Some basic important stuffs #Computer Game Design #Java Short Notes","author":"Author-Check- Article-or-Video","date":"July 27, 2021","format":false,"excerpt":"Data types to represent telephone numbers:a string of ten digits can represent all ten-digit telephone numbers.an object can hold data (integers or strings) of the elements of a telephone numberan integer data type can represent all ten-digit numbers--a boolean can only represent two valuesan enumerated type can only represent a\u2026","rel":"","context":"In &quot;FromSitesTree.com&quot;","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":10536,"url":"http:\/\/bangla.sitestree.com\/?p=10536","url_meta":{"origin":67690,"position":1},"title":"Code examples for interfaces","author":"","date":"August 29, 2015","format":false,"excerpt":"**************************** Code examples for interfaces: \u00a0\u00a0\u00a0 * Class1.java implements Interface1.java \u00a0\u00a0\u00a0 * Abstract Class2.java implements Interface1.java and Interface2.java \u00a0\u00a0\u00a0 * Class3.java extends abstract class Class2.java \u00a0\u00a0\u00a0 * Interface3.java extends Interface1.java and Interface2.java *************************** ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Class1.java ~~~~~~~~~~~~~~~~~~~~~~~~~~~ \/\/ This class is not abstract, so it must provide \/\/ implementations of method1\u2026","rel":"","context":"In &quot;Code . Programming Samples . \u09aa\u09cd\u09b0\u09cb\u0997\u09cd\u09b0\u09be\u09ae \u0989\u09a6\u09be\u09b9\u09b0\u09a8&quot;","block_context":{"text":"Code . Programming Samples . \u09aa\u09cd\u09b0\u09cb\u0997\u09cd\u09b0\u09be\u09ae \u0989\u09a6\u09be\u09b9\u09b0\u09a8","link":"http:\/\/bangla.sitestree.com\/?cat=1417"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":26565,"url":"http:\/\/bangla.sitestree.com\/?p=26565","url_meta":{"origin":67690,"position":2},"title":"Code examples for interfaces #Programming Code Examples #Java\/J2EE\/J2ME #Object Oriented Programming","author":"Author-Check- Article-or-Video","date":"April 28, 2021","format":false,"excerpt":"**************************** Code examples for interfaces: * Class1.java implements Interface1.java * Abstract Class2.java implements Interface1.java and Interface2.java * Class3.java extends abstract class Class2.java * Interface3.java extends Interface1.java and Interface2.java *************************** ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Class1.java ~~~~~~~~~~~~~~~~~~~~~~~~~~~ \/\/ This class is not abstract, so it must provide \/\/ implementations of method1 and method2. public class\u2026","rel":"","context":"In &quot;FromSitesTree.com&quot;","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":65838,"url":"http:\/\/bangla.sitestree.com\/?p=65838","url_meta":{"origin":67690,"position":3},"title":"SCJP: Class Declarations #Java Short Notes #SCJP","author":"Sayed","date":"July 16, 2021","format":false,"excerpt":"class declarations Start with modifiers such as public, private followed by class keyword The class name, with the initial letter capitalized The name of the class's parent (superclass), preceded by the keyword extends (if any). A class can only extend (subclass) one parent. list of interfaces implemented by the class,\u2026","rel":"","context":"In &quot;FromSitesTree.com&quot;","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":66316,"url":"http:\/\/bangla.sitestree.com\/?p=66316","url_meta":{"origin":67690,"position":4},"title":"Java Fundamentals #Java Short Notes","author":"Author-Check- Article-or-Video","date":"July 18, 2021","format":false,"excerpt":"An abstract class may have constructors It is illegal to invoke the new operator on an abstract class An abstract class is allowed to have method implementations There is no restriction about the placement of abstract classes in a class hierarchy It is legal for an abstract class to implement\u2026","rel":"","context":"In &quot;FromSitesTree.com&quot;","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":70253,"url":"http:\/\/bangla.sitestree.com\/?p=70253","url_meta":{"origin":67690,"position":5},"title":"Financial Transaction: Java Data Type #1","author":"Author-Check- Article-or-Video","date":"August 30, 2021","format":false,"excerpt":"Best data type for Financial Transactions: Object with two integer type variables. One for the dollars and another for the cents. floating points are inappropriate as they suffer from round-off errors.For financial software how to create a common class for contracts that multiple independent classes will satisfy?Using interfacebecause for independent\u2026","rel":"","context":"In &quot;FromSitesTree.com&quot;","block_context":{"text":"FromSitesTree.com","link":"http:\/\/bangla.sitestree.com\/?cat=1917"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts\/67690","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=67690"}],"version-history":[{"count":0,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=\/wp\/v2\/posts\/67690\/revisions"}],"wp:attachment":[{"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=67690"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=67690"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/bangla.sitestree.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=67690"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}