2. Abstract class and interface difference
(1) interface can be multiple implements, can only be a single abstract class extends
(2) only the definition of interfaces, abstract class can have the definition and implementation
(3) the definition of the default interface for the field: public static final, abstract class field by default are "friendly" (this package can be seen)
5. What is Web container?
J2EE implementation protocol specification web applications. The protocol defines a web procedures runtime environment, including: concurrency, security, lifecycle management and so on.
6. To explain the following regarding the term J2EE
(1) JNDI: Java Naming & Directory Interface, JAVA naming directory services. The main features provided are: to provide a directory system that allows other applications around the top left, in its own index, to meet the fast search and location of distributed application functionality. V
(2) JMS: Java Message Service, JAVA Message Service. The main implementation of various communications between applications. Including point-to-point and broadcasting.
(3) JTA: Java Transaction API, JAVA Affairs Service. To provide a variety of Distributed Transaction Service. Application simply call the interface can be provided.
(4) JAF: Java Action FrameWork, JAVA security authentication framework. To provide some security control framework. Let developers through a variety of deployment and custom implementation of their personalized safety control strategy.
(5) RMI: Remote Method Interface, Remote Method Invocation
7.EJB which are based on the implementation of technology? And SessionBean and EntityBean tell the difference, StatefulBean and StatelessBean difference.
EJB including the Session Bean, Entity Bean, Message Driven Bean, based on JNDI, RMI, JAT, such as technology implementation.
SessionBean in J2EE applications are used to complete some server-side operations, such as access to the database, call other EJB components. EntityBean application system is used to represent the data used. For the client, SessionBean is a non-persistent object, which achieve some running on the server business logic; EntityBean is a persistent object, it represents a memory stored in the persistent entities in the target view, or an existing enterprise application implementation entity.
Session Bean can also be subdivided into Stateful Session Bean and Stateless Session Bean. Both the Session Bean can be placed on the system logical method of implementation are different Stateful Session Bean can record the caller's state, it is often to Say, a user will have a corresponding to the Stateful Session Bean entity. Stateless Session Bean, although the logic of components, but he did not record the user is responsible for state, that is to say when a user calls a Stateless Session Bean when, EJB Container will not find a specific entity Stateless Session Bean to implement this method. In other words, the most likely number of users in the implementation of certain methods of Stateless Session Bean, the Bean will be the same in the implementation of the Instance. from memory in terms of look, Stateful Session Bean and Stateless Session Bean comparison, Stateful Session Bean consume J2EE Server with more memory, however, the advantage of Stateful Session Bean is that he can maintain the user's state.
8.XML the analytical method
Sax, DOM, JDOM
9. What is a Web Service?
Web Service is for the original site of the isolation between the information be able to communicate with each other, sharing a proposed interface.
Web Service by using the Internet, unified, open standards, such as HTTP, XML, SOAP (Simple Object Access Protocol), WSDL and so on, so Web Service can support these standards in any environment (Windows, Linux) used.
Note: SOAP protocol (Simple Object Access Protocal, Simple Object Access Protocol), for it is a decentralized and distributed network environment information exchange XML-based communications protocol. In this protocol, the software components or applications can through standard HTTP protocol to communicate. Its design goal is simplicity and scalability, which helps a large number of heterogeneous processes and interoperability between platforms, so that the application be able to exist by a wide range of user access.
Advantages:
(1). Cross-platform.
(2). SOAP protocol is based on XML and HTTP these industry standards, by all the important companies.
(3). Because of the use of SOAP, the data are ASCII text rather than binary transmission, very convenient debugging; and because of this, its data easily through the firewall, the firewall does not need a separate procedure in order to open a "loophole."
(4). In addition, WebService implementation of the technical difficulty is much less than CORBA and DCOM.
(5). To achieve B2B integration, EDI relatively perfect and more complex; and use WebService, you can achieve low-cost, small companies can use.
(6). In the C / S process, WebService can be achieved without a whole page refresh with the server and check the number of dealings.
Disadvantage:
(1). WebService uses the XML data package, will cause a large amount of data to transmit in the network.
(2). WebService specification does not require any implementation-related details, including the object model, programming language, this point, it is better than CORBA.
10. Many threads there are several methods of implementation are what? Synchronization There are several methods of implementation are what?
Multi-threaded, there are two implementation methods are inherited separately Thread Class and Runnable Interface implementation
Synchronized implementation has two aspects, respectively, are synchronized, wait and notify
11.JSP dynamic and static INCLUDE distinction INCLUDE?
INCLUDE with dynamic jsp: include action implementation
<jsp:include page="included.jsp" flush="true"/>
It will always be to check the changes contained in the document, suitable for containing dynamic pages, and can take parameters
Static INCLUDE PN code used include implementation, will be contained in the document does not check for changes, applies to contain static pages
<% @ Include file = "included.htm"%>
(1) interface can be multiple implements, can only be a single abstract class extends
(2) only the definition of interfaces, abstract class can have the definition and implementation
(3) the definition of the default interface for the field: public static final, abstract class field by default are "friendly" (this package can be seen)
5. What is Web container?
J2EE implementation protocol specification web applications. The protocol defines a web procedures runtime environment, including: concurrency, security, lifecycle management and so on.
6. To explain the following regarding the term J2EE
(1) JNDI: Java Naming & Directory Interface, JAVA naming directory services. The main features provided are: to provide a directory system that allows other applications around the top left, in its own index, to meet the fast search and location of distributed application functionality. V
(2) JMS: Java Message Service, JAVA Message Service. The main implementation of various communications between applications. Including point-to-point and broadcasting.
(3) JTA: Java Transaction API, JAVA Affairs Service. To provide a variety of Distributed Transaction Service. Application simply call the interface can be provided.
(4) JAF: Java Action FrameWork, JAVA security authentication framework. To provide some security control framework. Let developers through a variety of deployment and custom implementation of their personalized safety control strategy.
(5) RMI: Remote Method Interface, Remote Method Invocation
7.EJB which are based on the implementation of technology? And SessionBean and EntityBean tell the difference, StatefulBean and StatelessBean difference.
EJB including the Session Bean, Entity Bean, Message Driven Bean, based on JNDI, RMI, JAT, such as technology implementation.
SessionBean in J2EE applications are used to complete some server-side operations, such as access to the database, call other EJB components. EntityBean application system is used to represent the data used. For the client, SessionBean is a non-persistent object, which achieve some running on the server business logic; EntityBean is a persistent object, it represents a memory stored in the persistent entities in the target view, or an existing enterprise application implementation entity.
Session Bean can also be subdivided into Stateful Session Bean and Stateless Session Bean. Both the Session Bean can be placed on the system logical method of implementation are different Stateful Session Bean can record the caller's state, it is often to Say, a user will have a corresponding to the Stateful Session Bean entity. Stateless Session Bean, although the logic of components, but he did not record the user is responsible for state, that is to say when a user calls a Stateless Session Bean when, EJB Container will not find a specific entity Stateless Session Bean to implement this method. In other words, the most likely number of users in the implementation of certain methods of Stateless Session Bean, the Bean will be the same in the implementation of the Instance. from memory in terms of look, Stateful Session Bean and Stateless Session Bean comparison, Stateful Session Bean consume J2EE Server with more memory, however, the advantage of Stateful Session Bean is that he can maintain the user's state.
8.XML the analytical method
Sax, DOM, JDOM
9. What is a Web Service?
Web Service is for the original site of the isolation between the information be able to communicate with each other, sharing a proposed interface.
Web Service by using the Internet, unified, open standards, such as HTTP, XML, SOAP (Simple Object Access Protocol), WSDL and so on, so Web Service can support these standards in any environment (Windows, Linux) used.
Note: SOAP protocol (Simple Object Access Protocal, Simple Object Access Protocol), for it is a decentralized and distributed network environment information exchange XML-based communications protocol. In this protocol, the software components or applications can through standard HTTP protocol to communicate. Its design goal is simplicity and scalability, which helps a large number of heterogeneous processes and interoperability between platforms, so that the application be able to exist by a wide range of user access.
Advantages:
(1). Cross-platform.
(2). SOAP protocol is based on XML and HTTP these industry standards, by all the important companies.
(3). Because of the use of SOAP, the data are ASCII text rather than binary transmission, very convenient debugging; and because of this, its data easily through the firewall, the firewall does not need a separate procedure in order to open a "loophole."
(4). In addition, WebService implementation of the technical difficulty is much less than CORBA and DCOM.
(5). To achieve B2B integration, EDI relatively perfect and more complex; and use WebService, you can achieve low-cost, small companies can use.
(6). In the C / S process, WebService can be achieved without a whole page refresh with the server and check the number of dealings.
Disadvantage:
(1). WebService uses the XML data package, will cause a large amount of data to transmit in the network.
(2). WebService specification does not require any implementation-related details, including the object model, programming language, this point, it is better than CORBA.
10. Many threads there are several methods of implementation are what? Synchronization There are several methods of implementation are what?
Multi-threaded, there are two implementation methods are inherited separately Thread Class and Runnable Interface implementation
Synchronized implementation has two aspects, respectively, are synchronized, wait and notify
11.JSP dynamic and static INCLUDE distinction INCLUDE?
INCLUDE with dynamic jsp: include action implementation
<jsp:include page="included.jsp" flush="true"/>
It will always be to check the changes contained in the document, suitable for containing dynamic pages, and can take parameters
Static INCLUDE PN code used include implementation, will be contained in the document does not check for changes, applies to contain static pages
<% @ Include file = "included.htm"%>