First, Java language
1, three basic characteristics of object-oriented
2, the concept and difference of method overload and method rewriting
3, interface and internal class, the characteristics of abstract classes
4. Basic class read and write
** 5, serialization precautions and how to implement serialization
6, the basic concept of thread, the basic state of the thread and the relationship between state
7, the synchronization of threads, how to implement the synchronization of threads
8, several common data structures and internal implementation principles.
9, Socket Communication (TCP, UDP Differences, Java Implementation)
** 10, Java's event entrustment mechanism and garbage collection mechanism
11. Basic steps for JDBC calls the database
** 12, parse several ways and differences in XML files
13. Definition of four basic permissions of Java
14, Java Internationalization
Second, JSP
1, at least you can say that 7 implied objects and their differences
** 2, the difference between Forward and Redirect
3, JSP common instructions
Third, servlet
1, call doget () and dopost () under what circumstances?
2, the intervilet's init () method and service () method difference
3, the life cycle of servlet
4, how to real real servlet single-thread mode
5, servlet configuration
6, four session tracking technology
Four, EJB
** 1, EJB container provided by the EJB container
It mainly provides services such as declaration cycle management, code generation, continuous management, security, transaction management, lock and distribution management.
2, EJB role and three objects
EJB roles mainly include Bean Developers Application Assembarer Deployer System Administrator EJB Container Provider EJB Server Provider
Three objects are Remote (local) interface, home (localhome) interface, Bean class
2, several types of EJB
Session Bean, entity (Entity) bean message driver (Message Driven) bean
Session bean can be divided into stateful and stateless
Entity Beans can be divided into two kinds of sustainability (BMP) and container management of bean management (CMP)
3, life cycle of the bean instance
For Stateless Session Bean, Entity Bean, Message Driven Bean typically exists in cache management, which typically contains Cache management, set up the context, create EJB Object (create), business method call, remove, etc. Procedure, for the bean in which the buffer is managed, the instance is not removed from memory, but the buffer pool scheduling mechanism continues to reuse the instance, and the bean in which Cache Management is used, the BEAN is maintained by activating and deactivating the mechanism. Limit the number of instances in memory.
4, activation mechanism
Take the Statefull Session Bean as an example: The Cache size determines the number of bean instances that can exist in memory, according to the MRU or NRU algorithm, instance migrate between activation and deactivation, activation mechanism is when the client calls an EJB When an instance business method, if the corresponding EJB Object discovers that it does not bind the corresponding bean instance, the reactive bean storage (by serializing mechanism storage instance) is replied (activated) this instance. The corresponding EJBACTIVE and EJBPASSIVATE methods are called before the state change.
5, the main role of the Remote interface and HOME interface
The REMOTE interface defines a business method for the EJB client calling business method.
The HOME interface is an EJB factory for creating and removing a lookup EJB instance
6. Several basic steps for customer service end calling EJB objects
First, set the JNDI service factory and the JNDI service address system properties, find the Home interface
Third, call the CREATE method from the home interface to create a Remote interface
Fourth, call its business method through the Remote interface
V. Database
1. Writing of the stored procedure
2. Basic SQL statement
Sixth, WebLogic
1. How to specify the size of the memory to WebLogic?
In the Script of WebLogic (bitservername in the Domian corresponding server directory), add SET MEM_ARGS = -XMS32M -XMX200M, adjust the minimum memory to 32M, maximum 200M
2, how to set the hot start mode (development mode) of WebLogic and product release mode?
The startup mode of the corresponding server can be modified in the management console is one of the development or product modes. Or modify the service startup file or Comufact of the Commenv file, add set production_mode = true.
3, do you need to enter your username and password when starting?
Modify the service launch file, add WLS_USER and WLS_PW items. You can also add an encrypted username and password in the boot.properties file.
4. After the WebLogic Management Table is configured for a application domain (or a website, Domain) for JMS and EJB or connection pool, and what file is actually saved?
Save in the config.xml file of this Domain, it is the core profile of the server.
5. Talk about the default directory structure of a Domain in WebLogic? For example, put a simple helloWorld.jsp into the why directory, but you can be http: // host on the browser: port number // HelloWord .jsp You can see the result of the running?
Domain Directory / Server Directory / Applications, place the application directory in this directory will be available as an application access. If it is a web application, the application directory needs to meet the web application directory requirements, the JSP file can be placed directly in the application directory, Javabean needs to be put In the CLASSES directory for the application directory, the default application that sets the server will be able to implement the application name on your browser.
6, how do I view EJBs already released in WebLogic?
You can use the management console, you can view all published EJBs in its deployment
7, how to make SSL configurations in WebLogic and the client's authentication configuration or talk about J2EE (standard) for SSL configuration
Using DemoIdentity.jks and Demotrust.jks KeyStore in the default installation, you need to configure the server to use Enable SSL, configure its port, you need to get private key and digital certificate from CA in product mode, create Identity and Trust KeyStore, load get Keys and digital certificates. You can configure this SSL connection to one-way or two-way.
8, which configuration files need to be involved in the WEBLOGIC
The configuration files involved in different types of EJBs have different configuration files including EJB-jar.xml, weblogic-ejb-jar.xmlcmp entity beans generally need WebLogic-Cmp-Rdbms-jar.xml
9, EJB needs to implement its business interface or home interface, please briefly describe the reasons.
The remote interface and home interface do not need to be directly implemented, and their implementation code is generated by the server, and the implementation class in the program run is used as an instance of the corresponding interface type.
10. Talk about the difference between Persistent and Non-Persisten when developing message beans in WebLogic
The MDB of the Persistent method ensures the reliability of the message delivery, that is, if the EJB container has problems, the JMS server will send the message when this MDB can be used, and the Non-Persistent method will be discarded.
11. Talk about how many common modes in J2EE you are familiar with or have heard? And some views of design patterns session facade pattern: Use SessionBean to access EntityBean
Message Facade Pattern: Realization asynchronous call
EJB Command Pattern: Use Command JavaBeans to replace sessionBean to achieve lightweight access
Data Transfer Object Factory: Simplify EntityBean Data Provision for DTO Factory
Generic Attribute Access: Simplify EntityBean Data Provision for EntityBeaN
Business Interface: Realize the same interface to specify business logic through remote (local) interface and bean classes
The design of the EJB architecture will directly affect the performance, scalability, maintenanceability, components reusability and development efficiency. The more complicated the project, the brighter the project team, the more important it can reflect the importance of good design.
