glossary.html

java基础学习

<dt><i>container-managed transaction</i>
<dd>When an EJB container defines the boundaries of a transaction. An entity bean must use container-managed transactions.
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<dt><i>context attribute</i>
<dd>An object bound into the context associated with a servlet.
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<dt><i>continue</i>
<dd>A Java programming language keyword used to resume program execution at the end of the current loop. If followed by a label, &quot;continue&quot; resumes execution where the label occurs.
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<dt><i>conversational state</i>
<dd>The field values of a session bean plus the transitive closure of the objects reachable from the bean's fields. The transitive closure of a bean is defined in terms of the serialization protocol for the Java programming language, that is, the fields that would be stored by serializing the bean instance.
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<dt><i>CORBA</i>
<dd>Common Object Request Broker Architecture. A language independent, distributed object model specified by the Object Management Group (OMG).
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<dt><i>core class</i>
<dd>A public class (or interface) that is a standard member of the Java Platform.  The intent is that the core classes for the Java platform, at minimum, are available on all operating systems where the Java platform runs.  A program written entirely in the Java programming language relies only on core classes, meaning it can run anywhere.  <!--See also, <i><a href="#purejava">100% Pure Java</a></i>-->.
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<dt><i>Core Packages</i>
<dd>The required set of APIs in a Java platform edition which must be supported in any and all compatible implementations.
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<dt><i>create method</i>
<dd>A method defined in the home interface and invoked by a client to create an enterprise bean.
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<dt><i>credentials</i>
<dd>The information describing the security attributes of a principal. Credentials can be acquired only through authentication or delegation.
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<dt><i>critical section</i>
<dd>A segment of code in which a thread uses resources (such as certain instance
variables) that can be used by other threads, but that must not be used by them
at the same time.
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<dt><i>CTS</i>
<dd>Compatibility Test Suite. A suite of compatibility tests for verifying that a J2EE product complies with the J2EE platform specification.
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<dt><i>declaration</i>
<dd>A statement that establishes an identifier and associates attributes with it, without necessarily reserving its storage (for data) or providing the implementation (for methods). See also <i>definition</i>.
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<dt><i>default</i>
<dd>A Java programming language keyword optionally used after all &quot;case&quot; conditions in a &quot;switch&quot; statement. If all &quot;case&quot; conditions are
not matched by the value of the "switch" variable, the "default" keyword will be executed.
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<dt><i>definition</i>
<dd>A declaration that reserves storage (for data) or provides implementation (for methods). See also <i>declaration</i>.
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<dt><i>delegation</i>
<dd>An act whereby one principal authorizes another principal to use its identity or privileges with some restrictions.
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<dt><i>Deployer</i>
<dd>A person who installs modules and J2EE applications into an operational environment.
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<dt><i>deployment</i>
<dd>The process whereby software is installed into an operational environment.
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<dt><i>deployment descriptor</i>
<dd>An XML file provided with each module and application that describes how they should be deployed. The deployment descriptor directs a deployment tool to deploy a module or application with specific container options and describes specific configuration requirements that a deployer must resolve.
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<dt><i>deprecation</i>
<dd>Refers to a class, interface, constructor, method or field that is no longer
recommended, and may cease to exist in a future version.
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<dt><i><a name="derived">derived from</a></i>
<dd>Class X is "derived from" class Y if class X <i>extends</i> class Y. See also <i><a href="#subclass">subclass</a></i>, <i><a href="#superclass">superclass</a></i>.
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<dt><i>distributed</i>
<dd>Running in more than one address space.
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<dt><i>distributed application</i>
<dd>An application made up of distinct components running in separate runtime environments, usually on different platforms connected through a network. Typical distributed applications are two-tier (client/server), three-tier (client/middleware/server), and n-tier (client/multiple middleware/multiple servers).
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<dt><i>do</i>
<dd>A Java programming language keyword used to declare a loop that will iterate a block of statements. The loop's exit condition can be specified with the &quot;while&quot; keyword.</dd>
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<dt><i>DOM</i>
<dd>Document Object Model. A tree of objects with interfaces for traversing the tree and writing an XML version of it, as defined by the W3C specification.
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<dt><i>double</i>
<dd>A Java programming language keyword used to define a variable of type double.</dd>
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<dt><i><a name="double">double precision</a></i>
<dd>In the Java programming language specification, describes a floating point number that
holds 64 bits of data. See also <i><a href="#single">single precision</a></i>.
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<dt><i>DTD</i>
<dd>Document Type Definition. A description of the structure and properties of a class of XML files.
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<dt><i>ebXML</i>
<dd>ebXML builds upon the XML (Extensible Markup Language) standard to deliver a
modular suite of specifications that enables enterprises of any size and in any geographical location to conduct business over the Internet. It provides companies and organizations with a standard method to exchange business messages, conduct trading relationships, communicate data in common terms and define and register business processes.
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<dt><i>EJB container</i>
<dd>A container that implements the EJB component contract of the J2EE architecture. This contract specifies a runtime environment for enterprise beans that includes security, concurrency, life cycle management, transaction, deployment, and other services. An EJB container is provided by an EJB or J2EE server.
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<dt><i>EJB Container Provider</i>
<dd>A vendor that supplies an EJB container.
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<dt><i>EJB context</i>
<dd>An object that allows an enterprise bean to invoke services provided by the container and to obtain the information about the caller of a client-invoked method.
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<dt><i>EJB home object</i>
<dd>An object that provides the life cycle operations (create, remove, find) for an enterprise bean. The class for the EJB home object is generated by the container's deployment tools. The EJB home object implements the enterprise bean's home interface. The client references an EJB home object to perform life cycle operations on an EJB object. The client uses JNDI to locate an EJB home object.
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<dt><i>EJB .jar file</i>
<dd>A JAR archive that contains an EJB module.
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<dt><i>EJB module</i>
<dd>A software unit that consists of one or more enterprise beans and an EJB deployment descriptor.
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<dt><i>EJB object</i>
<dd>An object whose class implements the enterprise bean's remote interface. A client never references an enterprise bean instance directly; a client always references an EJB object. The class of an EJB object is generated by the container's deployment tools.
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<dt><i>EJB server</i>
<dd>Software that provides services to an EJB container. For example, an EJB container typically relies on a transaction manager that is part of the EJB server to perform the two-phase commit across all the participating resource managers.  The J2EE architecture assumes that an EJB container is hosted by an EJB server from the same vendor, so does not specify the contract between these two entities. An EJB server may host one or more EJB containers.
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<dt><i>EJB Server Provider</i>
<dd>A vendor that supplies the EJB server.
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<dt><i>EIS resource</i>
<dd>An entity that provides EIS-specific functionality to its clients. Examples are: a record or set of records in a database system, a business object in an ERP system, and a transaction program in a transaction processing system.
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<dt><i>else</i>
<dd>A Java programming language keyword used to execute a block of statements in the case that the test condition with the &quot;if&quot; keyword evaluates to false.
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<dt><i>EmbeddedJava Technology</i>
<dd>The availability of Sun's Java 2 Platform, Micro Edition technology under a restrictive license agreement that allows a licensee to leverage certain Java technologies to create and deploy a closed-box application that exposes no APIs.
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<dt><i>encapsulation</i>
<dd>The localization of knowledge within a module. Because objects encapsulate data and implementation, the user of an object can view the object as a black box that provides services. Instance variables and methods can be added, deleted, or changed, but as long as the services provided by the object remain the same, code that uses the object can continue to use it without being rewritten. See also <i><a href="#ivariable">instance variable</a></i>, <i>instance
method</i>.
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<dt><i>enterprise bean</i>
<dd>A component that implements a business task or business entity; either an entity beans or a session bean.
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<dt><i>Enterprise Information System (EIS)</i>
<dd>The applications that comprise an enterprise's existing system for handling company-wide information. These applications provide an information infrastructure for an enterprise. An EIS offers a well defined set of services to its clients. These services are exposed to clients as local and/or remote interfaces. Examples of EISs include: an ERP system, a mainframe transaction processing system, and a legacy database system.
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<dt><i>Enterprise Bean Provider</i>
<dd>An application programmer who produces enterprise bean classes, remote and home interfaces, and deployment descriptor files, and packages them in an EJB .jar file.
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<dt><i>Enterprise JavaBeans (EJB)</i>
<dd>A component architecture for the development and deployment of object-oriented, distributed, enterprise-level applications. Applications written using the Enterprise JavaBeans architecture are scalable, transactional, and multi-user and secure.
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<dt><i>entity bean</i>
<dd>An enterprise bean that represents persistent data maintained in a database. An entity bean can manage its own persistence or it can delegate this function to its container. An entity bean is identified by a primary key. If the container in which an entity bean is hosted crashes, the entity bean, its primary key, and any remote references survive the crash.
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<dt><i>exception</i>
<dd>An event during program execution that prevents the program from continuing normally; generally, an error. The Java programming language supports exceptions with the try, catch, and throw keywords. See also <i>exception handler</i>.
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<dt><i>exception handler</i>
<dd>A block of code that reacts to a specific type of <i>exception</i>. If the exception is for an error that the program can recover from, the program can resume executing after the exception handler has executed.
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<dt><i>executable content</i>
<dd>An application that runs from within an HTML file.  See also <i><a href="#applet">applet</a></i>.
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<dt><i>extends</i>
<dd>Class X extends class Y to add functionality, either by adding fields or methods to class Y, or by overriding methods of class Y. An interface extends another interface by adding methods.  Class X is said to be a subclass of class Y.  See also <i><a href="#derived">derived from</a></i>.
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<dt><i>FCS</i>
<dd>First Customer Ship. The day in which a product is released/shipped to the
customer.
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<dt><i><a name="field">field</a></i>
<dd>A data member of a class. Unless specified otherwise, a field is not static.
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<dt><i>final</i>
<dd>A Java programming language keyword. You define an entity once and cannot change it or derive from it later. More specifically: a final class cannot be subclassed, a final method cannot be overridden and a final variable cannot change from its initialized value.</dd>
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<dt><i>finally</i>
<dd>A Java programming language keyword that executes a block of statements regardless of whether a Java Exception, or run time error, occurred in a block defined previously by the &quot;try&quot; keyword.</dd>
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<dt><i>finder method</i>
<dd>A method defined in the home interface and invoked by a client to locate an entity bean.
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<dt><i>float</i>
<dd>A Java programming language keyword used to define a floating point number variable.
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<dt><i>for</i>
<dd>A Java programming language keyword used to declare a loop that reiterates statements. The programmer can specify the statements to be executed, exit conditions, and initialization variables for the loop.</dd>
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<dt><i>form-based authentication</i>
<dd>When a web container provides an application-specific form for logging in.
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<dt><i>FTP</i>
<dd>The basic Internet File Transfer Protocol.  FTP, which is based on TCP/IP, enables the fetching and storing of files between hosts on the Internet.
See also <i><a href="#tcp">TCP/IP</a></i>.
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<dt><i><a name="formal">formal parameter list</a></i>
<dd>The parameters specified in the definition of a particular method. See also <i><a href="#actual">actual parameter list</a></i>.
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<dt><i>garbage collection</i>
<dd>The automatic detection and freeing of memory that is no longer in use. The Java runtime system performs garbage collection so that programmers never explicitly free objects.
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