锅塌里脊: JAVA2JSP绝对入门（三）（转）

JAVA2JSP学习的门槛相对比较的高
所涉及的专业技术语也是很多
下面是我自己搜录的，请看：

J2SE = Java 2 Standard Edition = Java2标准版
J2EE = Java 2 Enterprise Edition = Java2企业版（包括JSP/Servlet、EJB、JNDI、JTA等）
J2SDK == JDK = Java 2 Standard Development Kit = Java2标准开发工具集
J2RE == JRE = Java 2 Runtime Environment = Java2运行时环境
JVM == Java Virtual Machine = Java虚拟机

有关JVM的介绍请看
http://www.cnbruce.com/blog/showlog.asp?cat_id=26&log_id=287

J2SDK 内是包含J2RE的，所以一般来说，下载了J2SDK，就既有编译调试Java程序的功能，又能执行Java应用程序（Java Application）和Java小程序(Java Applet)。但如果只有J2RE，则不能编译调试Java程序(没有javac命令，不能编译Java源代码)，仅能运行Java程序（在MS- DOS窗口的命令行执行或双击.jar图标执行）和在浏览器（IE/Navigator/Mozilla）里运行Java小程序。如果你已经安装了 JBuilder或WebLogic Server，它们已经自带了jdk1.3.1（按其具体位置（如“c:\jbuilder7\jdk1.3”或“c:\bea\jdk131_03”）设置所需的JAVA_HOME环境变量的值），可以不必下载网上的j2sdk 1.4.2。

其中Java2 Platform 平台包括了如下内容

<html> <head> <title>New Features</title> </head> <body bgcolor="#FFFFFF"> <table summary="layout" border="0" width="100%"> <tr>  <td> <img src="../images/javalogo52x88.gif" alt="Java" border="0" width="52" height="88" /> </td> <td> <center> <h1>JavaTM 2 SDK, Standard Edition, version 1.4.2 Summary of New Features and Enhancements</h1> </center> </td> <td align="RIGHT" valign="TOP"> <a href="../index.html">Contents</a>  </tr> </table>  <hr style="font-size:100%;"> <blockquote> Version 1.4.0 of the Java 2 SDK, Standard Edition was a major feature release. The features listed below are those introduced in 1.4.0 (since 1.3). Version 1.4.2 is a maintenance release and introduces the minor enhancements and changes (since 1.4.1) listed at <a href="http://java.sun.com/j2se/1.4.2/changes.html">Enhancements and Changes in J2SE 1.4.2</a> on the web site. The full list of features, including features brought forward from previous versions, is available at <a href="../index.html#guide">Guide to Features</a>. </blockquote> <blockquote> <dl> <dt><dd>Java 2 Platform <ul> <li><a href="#xmlprocessing">XML Processing</a> <li><a href="#nio">New I/O APIs</a> <li><a href="#security">Security</a> <li><a href="#2d">Java 2DTM technology</a> <li><a href="#imageio">Image I/O Framework</a> <li><a href="#jps">Java Print Service</a> <li><a href="#awt">AWT</a> <li><a href="#Swing">Swing</a> <li><a href="#dnd">Drag and Drop</a> <li><a href="#logging">Logging API</a> <li><a href="#jws">JavaTM Web Start Product</a> <li><a href="#persistence">Long-term Persistence of JavaBeansTM Components</a> <li><a href="#jdbc">JDBCTM 3.0 API</a> <li><a href="#assertions">Assertion Facility</a> <li><a href="#preferences">Preferences API</a> <li><a href="#chained-exceptions">Chained Exception Facility</a> <li><a href="#standards">Endorsed Standards Override Mechanism</a> <li><a href="#vm">Java Virtual Machines</a> <li><a href="#performance">Performance</a> <li><a href="#networking">Networking Support, Including IPv6</a> <li><a href="#rmi">RMI</a> <li><a href="#serialization">Serialization</a> <li><a href="#jndi">Java Naming and Directory InterfaceTM (JNDI)</a> <li><a href="#corba">CORBA, Java IDL, and RMI-IIOP</a> <li><a href="#jpda">JavaTM Platform Debugger Architecture</a> <li><a href="#i18n">Internationalization</a> <li><a href="#plugin">JavaTM Plug-in Product</a> <li><a href="#collections">Collections Framework</a> <li><a href="#access">Accessibility</a> <li><a href="#regex">Regular Expressions</a> <li><a href="#math">Math</a> <li><a href="#reflection">Reflection</a> <li><a href="#jni">Java Native Interface</a> </ul> <dt><dd>Tools <ul> <li><a href="#tools">Tools and Utilities</a> </ul> </dl> </blockquote> <hr />  <a name="java2platform"></a> <h2>Java 2 Platform</h2> <a name="xmlprocessing"></a> <ul> <li><a href="../guide/xml/jaxp/index.html">XML Processing</a> <blockquote>The JavaTM API for XML processing has been added to the Java 2 Platform. It provides basic support for processing XML documents through a standardized set of Java Platform APIs. </blockquote> <a name="nio"></a> <li><a href="../guide/nio/index.html">New I/O APIs</a> <blockquote> The new I/O (NIO) APIs provide new features and improved performance in the areas of buffer management, character-set support, regular-expression matching, file I/O, and scalable network I/O. </blockquote> <a name="security"></a> <li><a href="../guide/security/index.html">Security</a> <ul> <li>The <a href="../guide/security/jce/JCERefGuide.html"> JavaTM Cryptography Extension (JCE)</a>, <a href="../guide/security/jsse/JSSERefGuide.html"> JavaTM Secure Socket Extension (JSSE)</a>, and <a href="../guide/security/jaas/JAASRefGuide.html"> JavaTM Authentication and Authorization Service (JAAS)</a> security features have now been integrated into the JavaTM 2 SDK, Standard Edition (Java 2 SDK), v 1.4 rather than being optional packages. <li>There are two new security features: <ul> <li>The <a href="../guide/security/jgss/tutorials/index.html"> JavaTM GSS-API</a> can be used for securely exchanging messages between communicating applications using the Kerberos V5 mechanism. <li>The <a href="../guide/security/certpath/CertPathProgGuide.html"> JavaTM Certification Path API</a> includes new classes and methods in the <code>java.security.cert</code> package that allow you to build and validate certification paths (also known as "certificate chains"). </ul> <li>Due to import control restrictions, the JCE jurisdiction policy files shipped with the Java 2 SDK, v 1.4 allow "strong" but limited cryptography to be used. An "unlimited" version of these files indicating no restrictions on cryptographic strengths is available. <li>The JSSE implementation provided in this release includes strong cipher suites. However, due to U.S. export control restrictions, this release does not allow alternate "pluggable" SSL/TLS implementations to be used. For more information, please see the <a href="../guide/security/jsse/JSSERefGuide.html#Customization">JSSE Reference Guide</a>. <li>With the integration of JAAS into the Java 2 SDK, the <code>java.security.Policy</code> API handles Principal-based queries, and the default policy implementation supports Principal-based <code>grant</code> entries. Thus, access control can now be based not just on what code is running, but also on who is running it. <li>Support for dynamic policies has been added. In Java 2 SDK releases prior to version 1.4, classes were statically bound with permissions by querying security policy during class loading. The lifetime of this binding was scoped by the lifetime of the class loader. In version 1.4 this binding is now deferred until needed by a security check. The lifetime of the binding is now scoped by the lifetime of the security policy. <li>The graphical Policy Tool utility has been enhanced to enable specifying a Principal field indicating what user is to be granted specified access control permissions. </ul> <a name="2d"></a> <li><a href="../guide/2d/index.html">Java 2DTM Technology</a> <blockquote> Java 2D includes many new features including: performance improvements, support for hardware acceleration for offscreen images, a pluggable image I/O framework, a new print service API, and several new font features. </blockquote> <a name="imageio"></a> <li><a href="../guide/imageio/index.html">Image I/O Framework</a> <blockquote> The Java Image I/O Framework provides a pluggable architecture for working with images stored in files and accessed across the network. It offers substantially more flexibility and power than the current APIs for loading and saving images. </blockquote> <a name="jps"> <li><a href="../guide/jps/index.html">Java Print Service API</a> <blockquote> The JavaTM Print Service is a new Java Print API that enables client and server applications to: <ul> <li>Discover and select print services based on their capabilities <li>Specify the format of print data <li>Submit print jobs to services that support the document type to be printed. </ul> </blockquote> <a name="awt"></a> <li><a href="../guide/awt/index.html">AWT</a> <blockquote> Changes to the AWT package center on improving the robustness, behavior, and performance of programs that present a graphical user interface. A new focus architecture replaces the previous implementation and addresses many focus-related bugs caused by platform inconsistencies, and incompatibilities between AWT and Swing components. The new full-screen exclusive mode API supports high performance graphics by suspending the windowing system so that drawing can be done directly to the screen; a benefit to applications like games, or other rendering-intensive applications. Headless support is now enabled by new graphics environment methods that indicate whether a display, keyboard, and mouse can be supported in a graphics environment. The ability to disable native frame decorations is now available for applications which need to take full control of specifying how a frame will look; when enabled this prevents the rendering of a native titlebar, system menu, border, or other native operating system dependent screen components. The oft-requested mouse wheel, with a scroll wheel in place of the middle mouse button, is enabled with new built-in Java support for scrolling via the mouse wheel. Also, a new mouse wheel listener class allows customization of mouse wheel behavior. The AWT package has been modified to be fully 64-bit compliant and now runs on Solaris machines with 64-bit and 32-bit addresses. </blockquote> <a name="Swing"></a> <li><a href="../guide/swing/index.html">Swing</a> <blockquote> Many new features have been added to Swing. The new spinner component is a single line input field that allows the user to select a number or a value by cycling through a sequence of values using a tiny pair of up/down arrow buttons. The new formatted text field component allows formatting of dates, numbers, and strings, such as a text field that accepts only decimal money values. The Windows look and feel implementation is updated to track features available in the 2000/98 versions. A new drag and drop architecture provides seamless drag and drop support between components as well as an easy way to implement drag and drop in your customized Swing components - writing a couple of methods which describe the particulars of your data model is all that is required. Swing's progress bar component has been enhanced to support an indeterminate state; rather than showing the degree of completeness, the indeterminate progress bar uses constant animation to show that a time-consuming operation is occurring. Due to great customer demand, the tabbed pane component has been enhanced to support scrollable tabs. With this feature enabled, if all the tabs will not fit within a single tab run, the tabbed pane component will display a single, scrollable run of tabs, instead of wrapping the tabs onto multiple runs. The popup and popup factory classes, which were previously package private, have been exposed and made public so that programmers may customize or create their own popups. The new focus architecture is fully integrated into Swing. </blockquote> <a name="dnd"></a> <li><a href="../guide/dragndrop">Drag and Drop</a> <blockquote> Swing has added support for data transfer between applications. A drag and drop operation is a data transfer request that has been specified by a gesture with a graphical pointing device. In the case of copy/paste, data transfer is often initiated with the keyboard. The ability to transfer data takes two forms: Drag and drop (DnD) support and clipboard transfer via cut/copy/paste. See <a href="../guide/swing/1.4/dnd.html">Swing Data Transfer</a>. </blockquote> <a name="logging"></a> <li><a href="../guide/util/logging/index.html">Logging API</a> <blockquote> The Java Logging APIs facilitate software servicing and maintenance at customer sites by producing log reports suitable for analysis by end users, system administrators, field service engineers, and software development teams. The Logging APIs capture information such as security failures, configuration errors, performance bottlenecks, and/or bugs in the application or platform. </blockquote> <a name="jws"></a> <li><a href="../guide/jws/index.html">JavaTM Web Start Product</a> <blockquote> The Java Web Start product is a new application-deployment technology that is bundled with J2SE 1.4.0. With Java Web Start, you launch applications simply by clicking on a Web page link. If the application is not present on your computer, Java Web Start automatically downloads all necessary files. It then caches the files on your computer so the application is always ready to be relaunched anytime you want -- either from an icon on your desktop or from the browser link. And no matter which method you use to launch the application, the most current version of the application is always presented to you. </blockquote> <a name="persistence"></a> <li><a href="../guide/beans/index.html">Long-term Persistence of JavaBeans Components</a> <blockquote> The new persistence model is designed to handle the process of converting a graph of beans to and from a persistent form. The new API is suitable for creating archives of graphs of JavaBeans components as textual representations of their properties. See <a href="http://java.sun.com/j2se/1.4.2/docs/guide/beans/changes14.html">API Enhancements to the JavaBeans Component API</a>. </blockquote> <a name="jdbc"></a> <li><a href="../guide/jdbc/index.html">JDBC 3.0 API</a> <blockquote> The JDBC 3.0 API, comprised of packages <tt>java.sql</tt> and <tt>javax.sql</tt>, provides universal data access from the Java programming language. Using the JDBC 3.0 API, you can access virtualy any data source, from relational databases to spreadsheets and flat files. JDBC technology also provides a common base on which tools and alternative interfaces can be built. New features include the ability to set savepoints in a transaction, to keep result sets open after a transaction is committed, to reuse prepared statements, to get metadata about the parameters to a prepared statement, to retrieve keys that are automatically generated, and to have multiple result sets open at one time. There are two new JDBC data types, BOOLEAN and DATALINK, with the DATALINK type making it possible to manage data outside of a data source. This release also establishes the relationship between the JDBC Service Provider Interface and the Connector architechture. </blockquote> <a name="assertions"></a> <li><a href="../guide/lang/assert.html">Assertion Facility</a> <blockquote> An assertion facility has been added to the Java 2 Platform. Assertions are boolean expressions that the programmer believes to be true concerning the state of a computer program. For example, after sorting a list, the programmer might assert that the list is in ascending order. Evaluating assertions at runtime to confirm their validity is one of the most powerful tools for improving code quality, as it quickly uncovers the programmer's misconceptions concerning a program's behavior. </blockquote> <a name="preferences"></a> <li><a href="../guide/lang/preferences.html">Preferences API</a> <blockquote> This new feature is a simple API for managing user preference and configuration data. Applications require preference and configuration data to adapt to different users, environments and needs. Applications need a way to store, retrieve, and modify this data. This need is met by the Preferences API. The Preferences API is intended to replace most common uses of class <tt>java.util.Properties</tt>, rectifying many of its deficiencies, while retaining its light weight. </blockquote> <a name="standards"></a> <li><a href="../guide/standards/index.html">Endorsed Standards Override Mechanism</a> <blockquote> An endorsed standard is a JavaTM API defined through a standards process other than the <a href="http://www.jcp.org/">Java Community Process</a>SM (JCPSM). Because endorsed standards are defined outside the JCP, it is anticipated that such standards may be revised between releases of the Java 2 Platform. In order to take advantage of new revisions to endorsed standards, developers and software vendors may use the <a href="../guide/standards/index.html">Endorsed Standards Override Mechanism</a> to provide newer versions of an endorsed standard than those included in the Java 2 Platform as released by Sun Microsystems. </blockquote> <a name="chained-exceptions"></a> <li><a href="../guide/lang/chained-exceptions.html">Chained Exception Facility</a> <blockquote> This new facility provides a common API to record the fact that one exception caused another, to access causative exceptions, and to acess the entire "causal chain" as part of the standard stack backtrace, ensuring that preexisting programs will provide this information with no additional effort on the part of their authors. </blockquote> <a name="vm"></a> <li><a href="../guide/vm/index.html">Java Virtual Machines</a> <blockquote> The Java virtual machines in this release include several enhancements. <ul> <li>Signal-chaining facility. <li>64-bit support on SolarisTM-SPARCTM platform edition. <li>Error-reporting mechanism. <li>New command-line option for performing additional Java Native Interface (JNI) checks. <li>New facility for logging garbage-collection events. </ul> The Classic virtual machine is no longer shipped as part of the Java 2 SDK. </blockquote> <a name="performance"></a> <li><a href="../guide/performance/index.html">Performance</a> <blockquote> This release includes performance enhancements in many areas of the platform. See <a href="../guide/performance/speed.html">Performance Enhancements</a> for a description of some of them. </blockquote> <a name="networking"></a> <li><a href="../guide/net/index.html">Networking Support, Including IPv6</a> <blockquote> <a href="../guide/net/enhancements14.html">New features</a> include support for IPv6 in TCP- and UDP-based applications, and support for unconnected/unbound sockets, allowing more flexible socket creation, binding, and connection. A mechanism called Java Secure Socket Extension provides encryption for data sent via sockets, and a new class, <a href="../api/java/net/URI.html"><code>URI</code></a>, allows URI construction and parsing without the presence of a protocol handler. The FTP Protocol Handler has been overhauled for conformity to current standards. The default character set is now UTF8, and APIs have been added to enable other character schemes. A new class, <a href="../api/java/net/NetworkInterface.html"><code>NetworkInterface</code></a>, allows enumeration of interfaces and addresses, and JNDI DNS SP Support in <a href="../api/java/net/InetAddress.html"><code>InetAddress</code></a> enables applications to configure a pure Java name service provider. TCP out-of-band data provides support for legacy applications; a UDP Connection function registers destination address with the OS, enabling asynchronous errors to be returned on the UDP socket; and full SOCkS V5 and V4 TCP support includes auto-negotiation with the proxy for which version to use. In addition, there are improvements to streaming, request and response headers processing, and error handling. </blockquote> <a name="rmi"></a> <li><a href="../guide/rmi/index.html">RMI</a> <blockquote> Server-side Stack Traces Now Retained in Remote Exceptions The RMI runtime implementation will now preserve the server-side stack trace information of an exception that is thrown from a remote call, in addition to filling in the client-side stack trace as it did previous releases. Therefore, when such an exception becomes accessible to client code, its stack trace will now contain all of its original server-side trace data followed by the client-side trace. Service Provider Interface for <code>RMIClassLoader</code> Certain static methods of <code>java.rmi.server.RMIClassLoader</code> now delegate their behavior to an instance of a new service provider interface, <code>java.rmi.server.RMIClassLoaderSpi</code>. This service provider object can be configured to augment RMI's dynamic class loading behavior for a given application. By default, the service provider implements the standard behavior of all of the static methods in <code>RMIClassLoader</code>. See the class documentation of <code><a href="../api/java/rmi/server/RMIClassLoader.html">RMIClassLoader</a></code> and <code><a href="../api/java/rmi/server/RMIClassLoaderSpi.html">RMIClassLoaderSpi</a></code> for more details. Dynamic Server Host Name The <code>java.rmi.server.hostname</code> property can now be dynamically updated to indicate that future exports should use a new host name. Therefore, the new host name value will be contained in the stub for an object that is exported after the property is updated. </blockquote> <a name="serialization"></a> <li><a href="../guide/serialization/index.html">Serialization</a> <blockquote> This release has several <a href="../guide/serialization/relnotes14.html">changes and enhancements</a> to the serialization API, including <ul> <li>Support for deserialization of objects that are known to be unshared in the data-serialization stream. <li>Support for a class-defined readObjectNoData method. <li>Important bug fixes. </ul> </blockquote> <a name="jndi"></a> <li><a href="../guide/jndi/index.html">Java Naming and Directory InterfaceTM (JNDI)</a> <ul> <li>An Internet Domain Naming System (DNS) service provider is part of the Java 2 Platform, Standard Edition, v1.4. This component enables applications to read data stored in the DNS. <li> The JNDI Lightweight Directory Access Protocol (LDAP) service provider has security enhancements that enable applications to establish secure sessions over existing LDAP connections and to use different authentication protocols. <li> The JNDI CORBA Object Services (COS) naming service provider supports the <a href="ftp://ftp.omg.org/pub/docs/ptc/99-12-03.pdf">Interoperable Naming Service (INS) specification (99-12-03)</a>. </ul> <blockquote> See <a href="../guide/jndi/index.html#14changes">JNDI Enhancements</a> for details. </blockquote> <a name="corba"></a> <li>CORBA, <a href="../guide/idl/index.html">Java IDL</a>, and <a href="../guide/rmi-iiop/index.html">RMI-IIOP</a> <blockquote> The ORB shipping as part of Java 2 Platform now includes a Portable Object Adapter (POA) functionality. An ORB makes it possible for client(s) to make method invocations on the objects being supported by server(s) executing on the same or different machine(s). ThePOA functionality allows programmers to construct object implementations that are portable between different ORB products, provide support for objects with persistent identities, and much more. Other new features include Portable Interceptors, Interoperable Naming Service, GIOP 1.2 support, Dynamic Management of Any values, and new tools that support a persistent naming service and other features. To learn more about the new features in Java IDL and RMI-IIOP between J2SE v.1.3 and J2SE v.1.4, link to <a href="../guide/idl/jidlChanges.html">Changes in CORBA Features Between J2SE 1.3 and 1.4</a>. </blockquote> <a name="jpda"></a> <li><a href="../guide/jpda/index.html">JavaTM Platform Debugger Architecture</a> <blockquote> Full Speed Debugging Support The <a href="http://java.sun.com/products/hotspot/"> Java HotSpot[TM] virtual machine </a> now uses "full-speed debugging". In the previous version of HotSpot, when debugging was enabled, the program executed using only the interpreter. Now, the full performance advantage of HotSpot Technology is available to programs running with debugging enabled. The improved performance allows long running programs to be more easily debugged. It also allows testing to proceed at full speed and the launch of a debugger to occur on an exception. HotSwap This feature has been added to allow a class to be updated while under the control of a debugger. Instance Filters <code>EventRequests</code> now have the capability of specifying an instance filter, which restricts the events generated by the request to those in which the currently executing instance is the object specified. Support For Debugging Other Languages The Java Platform Debugger Architecture has been extended so that non-Java programming language source, which is translated to Java programming language source, can be debugged in the future. VMDeathRequests A request can now be made to control target VM termination notification, allowing clean shutdown synchronization </blockquote> <a name="i18n"></a> <li><a href="../guide/intl/index.html">Internationalization</a> <blockquote> Unicode 3.0 Support Character handling in J2SE 1.4 is based on version 3.0 of the Unicode standard. This affects the Character and String classes in the java.lang package as well as the collation and bidirectional text analysis functionality in the java.text package. Support for Thai and Hindi Thai and Hindi are now supported in all areas of functionality. See the <a href="../guide/intl/locale.doc.html">Supported Locales</a> document for complete information on supported locales and writing systems. Currency class The class <a href="../api/java/util/Currency.html"><tt>java.util.Currency</tt></a> was introduced so that currencies can be referenced independent of locales. There are new methods on <a href="../api/java/text/NumberFormat.html"><tt>java.text.NumberFormat</tt></a> and related classes to specify the currency for formatting monetary values. </blockquote> <a name="plugin"></a> <li><a href="../guide/plugin/index.html">JavaTM Plug-in Product</a> <blockquote> Java Plug-in 1.4 offers the following new features: support of HTTPS through Java Secure Socket Extension (JSSE) rather than the browser; enhanced applet caching so that other files, such as GIF, JPEG, AU, etc., can be cached as part of the download in addition to JAR and class files; applet persistence so that applets may persist across browser page changes; various applet-compatibility enhancements to allow most JDK 1.1 applets to run seemlessly in Java 2; and on Microsoft Windows platforms, support in Java Plug-in for launching applets using the <tt><applet></tt> tag. Version 1.4 also provides access to the DOM via standard, w3c-defined interfaces; assertion and logging support; applet usability enhancements, including a customizable progress bar for applet loading; and enhanced options in the Java Console to allow dynamic reconfiguration of proxy settings, the policy file, etc., while the applet is running. </blockquote> <a name="collections"></a> <li><a href="../guide/collections/index.html">Collections Framework</a> <blockquote> The collections framework has several enhancements in Java 2 SDK 1.4, including a marker interface to advertise random access, an identity-based (rather than equality-based) Map, insertion-order-preserving Map and Set implementations, and several new algorithms for manipulating and returning values from lists. See <a href="../guide/collections/changes4.html">Collections Framework Enhancements</a> for details. </blockquote> <a name="access"></a> <li><a href="../guide/access/index.html">Accessibility</a> <blockquote> New features include support for: <ul> <li>Mnemonic tab navigation on a JTabbedPane <li>Text editing by assistive technologies <li>Accessibility of HTML components <li>Accessibility of Swing Actions <li>List navigation using the first letter of list items <li>Component roles DATE_EDITOR, FONT_CHOOSER, GROUP_BOX, SPIN_BOX, STATUS_BAR <li>Properties to indicate the presence of a screen magnifier or screen reader, or to specify assistive technologies to load into the Java virtual machine </ul> </blockquote> <a name="regex"></a> <li><a href="../api/java/util/regex/package-summary.html">Regular Expressions</a> <blockquote> New package <a href="../api/java/util/regex/package-summary.html"><tt>java.util.regex</tt></a> contains classes for matching character sequences against patterns specified by regular expressions. </blockquote> <a name="math"></a> <li><a href="../guide/math/index.html">Math</a> <blockquote> A new, efficient method for generating prime numbers with no need for the caller to specify a certainty has been added to class <tt>java.math.BigInteger</tt>. </blockquote> <a name="reflection"></a> <li><a href="../guide/reflection/index.html">Reflection</a> <blockquote> Certain reflective operations, specifically <a href="../api/java/lang/reflect/Field.html">java.lang.reflect.Field</a>, <a href="../api/java/lang/reflect/Method.html#invoke(java.lang.Object, java.lang.Object[])">java.lang.reflect.Method.invoke()</a>, <a href="../api/java/lang/reflect/Constructor.html#newInstance(java.lang.Object[])">java.lang.reflect.Constructor.newInstance()</a>, and <a href="../api/java/lang/Class.html#newInstance()">Class.newInstance()</a>, have been rewritten for higher performance. Reflective invocations and instantiations are several times faster than in previous releases. </blockquote> <a name="jni"></a> <li><a href="../guide/jni/index.html">Java Native Interface</a> <blockquote> A few changes have been made to JNI in v 1.4. First, the version number has been incremented and the specification of <tt>JNI_OnLoad</tt> updated accordingly. Second, JNI has been enhanced to reflect a new feature of the <tt>java.nio</tt> package: direct buffers. The contents of a direct buffer can, potentially, reside in native memory outside of the ordinary garbage-collected heap. Finally, the new Invocation Interface routine <tt>AttachCurrentTreadAsDaemon</tt> allows native code to attach a daemon thread to the virtual machine; this is useful when the VM should not wait for this thread to exit upon shutdown. See <a href="../guide/jni/jni-14.html">JNI Enhancements</a> for more on these enhancements. </blockquote> </ul> <h2>Tools and Utilities</h2> <a name="tools"></a> <blockquote> See <a href="../tooldocs/tools-changes.html">Tool Changes</a> for details on the changes summarized here. </blockquote> <ul> <li> The <a href="../tooldocs/solaris/java.html">java</a> application launcher supports command-line options for support of the new Assertions Facility. On the SolarisTM Operating Environment (SPARCTM Platform Edition) new command-line options are available for specifying 64-bit or 32-bit operation. On all platforms, new option <tt>-Xloggc:file</tt> logs each garbage-collection event in the specified file. Also on all platforms, the new option <tt>-Xcheck:jni</tt> performs additional checks for Java Native Interface (JNI) functions at the cost of some performance degradation <li>The <a href="../tooldocs/solaris/javadoc.html">javadoc</a> tool has several new tags, a dozen new options, smarter inheriting of doc comments, more control over HTML output, improvements to the Doclet API, better error messages, dozens of bug fixes, and is easier to run. For more details, see <a href="../tooldocs/javadoc/whatsnew-1.4.html">What's New in Javadoc 1.4</a>. Downloaded separately from the SDK, the <a href="http://java.sun.com/javadoc/mifdoclet/">MIF doclet</a> has had a major upgrade -- it generates API documentation in FrameMaker and PDF format. <li> The <a href="../tooldocs/solaris/native2ascii.html">native2ascii</a> tool contains bug fixes to now correctly process source files encoded with Unicode encoding. <li>The <a href="../guide/rmi-iiop/toJavaPortableUG.html">idlj</a> tool now generates server-side bindings following the Portable Servant Inheritance Model. This change involves producing new POA bindings by default. A new command-line option is added to enable you to continue to generate backwards-compatible server-side bindings. To learn more about the <a href="../guide/idl/POA.html">Portable Servant Inheritance Model</a>, follow the link. <li>The <a href="../guide/idl/orbd.html">orbd</a> tool, or Object Request Broker Daemon, is a new alternative tool for the Transient Naming Service, <tt>tnameserv</tt>. ORBD includes both a Transient Naming Service and a Persistent Naming Service. The orbd tool is used to enable clients to transparently locate and invoke persistent objects on servers in the CORBA environment. The orbd tool incorporates the functionality of a Server Manager, an Interoperable Naming Service, and a Bootstrap Name Server. When used in conjunction with the <tt>servertool</tt>, the Server Manager locates, registers, and activates a server when a client wants to access the server. <li>The <a href="../guide/idl/servertool.html">servertool</a> is new to this release. The servertool provides an ease-of-use interface for application programmers to register, unregister, startup, and shutdown a server. <li>The <a href="../tooldocs/solaris/rmic.html">rmic</a> compiler has a new option to enable Portable Object Adapter, or POA support for Remote Method Invocation. The POA enables portability among vendor ORBs, among other uses. To learn more about the <a href="../guide/idl/POA.html">POA</a>, follow the link. To enable POA support with the <tt>rmic</tt> compiler, use the arguments <tt>rmic -iiop -poa</tt>. <li>The graphical Policy Tool utility has been enhanced to enable specifying a Principal field indicating what user is to be granted specified access control permissions. </ul>   <hr size="3"> <table summary="layout" border="0" width="100%"> <tr valign="TOP"> <td> <a href="SMICopyright.html">Copyright © 2002</a> Sun Microsystems, Inc. All Rights Reserved. </td> <td align="RIGHT"> <img src="../images/sunlogo64x30.gif" alt=" Sun Microsystems, Inc " border="0" width="64" height="30" /> </td> </tr> </table> <pre>  </pre> </body> </html>

[Ctrl+A 全部选择进行拷贝提示：可先修改部分代码，再点击运行]

JavaBean ：是一种组件，它在内部有接口或有与其相关的属性，以便不同人在不同时间开发的 bean 可以询问和集成。可以构建一个 bean，而在以后构造时将其与其它 bean 绑定。这种过程提供了先构建，然后重复使用的方法，这就是组件的概念。可以将这种单一应用程序部署成独立程序、ActiveX 组件或在浏览器中。JavaBean 因其外部接口（即属性接口）而与纯对象不同。这种接口允许工具读取组件要执行的功能，将其与其它 bean 挂钩，以及将其插入其它环境。JavaBean 设计成对单一进程而言是本地的，它们在运行时通常可视。这种可视组件可能是按钮、列表框、图形或图表 - 但这不是必需的。

EJB：

EJB的全称是Enterprise Java bean。是JAVA中的商业应用组件技术。EJB结构中的角色 EJB 组件结构是基于组件的分布式计算结构，是分布式应用系统中的组件。
　　一个完整的基于EJB的分布式计算结构由六个角色组成，这六个角色可以由不同的开发商提供，每个角色所作的工作必须遵循Sun公司提供的EJB规范，以保证彼此之间的兼容性。这六个角色分别是EJB组件开发者（Enterprise Bean Provider）、应用组合者（Application Assembler）、部署者（Deployer）、EJB服务器提供者（EJB Server Provider）、EJB 容器提供者（EJB Container Provider）、系统管理员（System Administrator）
EJB 是设计成运行在服务器上，并由客户机调用的非可视远程对象。可通过多个非可视 JavaBean 构建 EJB。它们有一个部署描述符，其目的与 JavaBean 属性相同：它是以后可由工具读取的 bean 的描述。EJB 还独立于平台，一旦编写好，还可以在任何支持 Java 的平台（包括客户机和服务器）上使用。

因为 EJB 由诸如 IBM VisualAge for Java 这样的工具集生成，所以，它是基于服务器的对象，并用于远程调用。它们安装在 EJB 服务器上，并象调用其它 CORBA 远程对象那样获得进行调用的远程接口。
EJB 的主要好处在于：构建 bean 时，bean 开发人员可以规定需要什么类型的行为，而不必规定如何去做。开发分为两部分：程序员开发 bean，然后验证：它可与构建工具一起工作，并包括标识所需服务质量行为种类的部署描述符。下一步，另一个程序员可以采用这个 bean，并使用读取 EJB 部署描述符的部署工具，然后将该 bean 安装到 Enterprise Java Server 上的容器中。在第二步中，部署工具采取一些操作 - 这可能意味着生成如状态保存代码，放入事务挂钩，或执行安全性检查这样的代码。所有这些操作由部署工具生成，bean 开发人员和部署人员可以是不同的人。

可以通过使用部署工具，将任何独立于平台的 JavaBean 改写成具有可靠服务质量、特定于平台的 EJB，以满足现有商业系统和应用程序的特定需求。这就是 EJB 服务器对集成系统、网络和体系结构如此重要的原因所在。

JBuilder

Jbuilder 是一个荣获多项奖项的产品，Inprise一向有支持开发者社区的传统，因此Jbuilder同时推出了linux的版本。Jbuilder提供一个可视化的开发集成环境，你可以方便的开发纯JAVA应用程序，APPLET,JAVA BEANS以及兼容J2EE的分布式的企业应用。Jbuilder可以和Enhydra，Bea WebLogic协同工作，加速团队的开发速度。总之，作JAVA应用开发，用JBUILDER，能够倍感轻松。

JCreator

JCreator 是一个Java程序开发工具，无论你是要开发Java应用程序或者网页上的Applet元件都难不倒它。在功能上与Sun公司所公布的JDK等文字模式程序工具相较之下来得容易操作，还允许使用者自订义操作窗口界面及无限Undo /Redo等功能。

JNDI

JNDI的全称是Java Naming and Directory Interface，可以理解为Java名称和目录服务接口。
JNDI向应用程序提供了一个查询和使用远程服务的机制。这些服务可以是任何企业服务。对于JDBC应用程序来说，JNDI提供的是数据库连接服务。当然JNDI也可以向数据库提供其他服务，但是这超出了本文范围，在此不做论述。

其实JNDI并不难理解。简单来说，名称服务提供了一个把文件，打印机，服务器等实体映射到一个逻辑名称的机制。例如在操作系统中的名称服务就把打印机映射到一个I/O端口。而目录服务可以理解为名称服务的一个扩展，它允许在服务中的各项拥有自己的属性。又以打印机为例，打印机可以是彩色打印机，支持双面打印，支持网络打印，支持高速打印等。所有这些打印机的属性都可以储存在目录服务中，和相应的打印机联系起来。一些常见的目录服务有NIS，NIS+， LDAP和Novell的NDS等。

那么现在已经很入门了，回到第一篇再看看，是不是有收获~！

标签： JAVA

锅塌里脊

1/12/2007

JAVA2JSP绝对入门（三）（转）

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