翻译文献Java Servlets的概要

翻译文献Java Servlets的概要 大连交通大学2016届本科生毕业设计(论文)外文翻译 外文原文 0verview of Java Servlets Servlets are protocol—and platform—independent server side components(written in Java，which dynamically extend Java enabled servers(They provide a general framework for services built using the request—response paradigm。Their initial use is to provide secure web—based access to data which is presented using HTML web pages，interactively viewing or modifying that data using dynamic web page generation techniques( Since servlets run inside servers，they do not need a graphical user interface .Otherwise，they are the Server side counterpart to applets(which are used only on the client side of systems):they are Java application components which are downloaded，on demand，to the part of the system which needs them Figure 1 Clients talking to Java Servlets in servers(Clients may range in complexity from simple HTML forms to sophisticated Java applets(Servlets will frequently use some kind of persistent storage，such as files or a database( Servlets are most often provided by organizations which provide customized multi—user services to their customer bases(However，servlets are also flexible enough to support standardized services such as serving static web pages through the HTTP(or HTTPS)protocols，and proxying services(Since they are used for dynamic extensibility，they may be used in a plug—in style，supporting facilities such as search engines and semi—custom applications(Servlets also provide a strong platform for semi—custom applications，such as web—based order entry or inventory systems Although all servlets are written in Java，their clients may be written in any language(When servlets are used in the middle tiers of distributed application systems，they can in turn be clients to other services， Written in any language(For example(servlets can use JDBC to contact an application’s highly tuned relational databases .Communicating with other kinds of current or legacy systems may call for alternate Software packages，as required by those systems( Many Ways to Use Servlets A few of the many applications for servlets include 大连交通大学2016届本科生毕业设计(论文)外文翻译 A simple servlet can process data which was POSTed over HTTPS using an HTML FORM，passing data such as a purchase order(with credit card data)(This would be part of an order entry and processing system，working with product and inventory databases and perhaps an on—line payment system( Since servlets handle multiple requests concurrently，the requests can be synchronized with each other to support collaborative applications such as on—line conferencing( One could define a community of active agents，which share work among each other(The code for each agent would be loaded as a servlet，and the agents would pass data to each other( One servlet could forward requests other servers(This technique can balance load among several servers which mirror the same content(Or，it could be used to partition a single logical service between several servers，routing requests according to task type or organizational boundaries( API Availability _j The Java Servlet API is a Standard Java Extension API(This means that while it is not part of the core Java framework which must always be part of all products bearing the Java brand，it will be made available with such products by their vendors as an add—on package( Sun has provided a package which may be used to embed servlet support in other web servers，including Apache(and derived servers such as Stronghold)(Netscape FastTrack and Enterprise servers，and Microsoft’s IIS( Servlets were initially supported in the Java Web Serverfrom Sun(Since then，a number of other Java-based web servers have supported the API，or committed to supporting it Features of the java(servlet API The servlet API is already suppoded by most Java based web servers,and implementalions are available for other popular web servers(This means that you get the Java Advantage when you use the servlet API not only will your code not have memory leaks and suffer from hard—to-find pointer bugs。but your code runs on platforms from many server vendors( You don’t need to lock yourself into a single—vendor server extension API，using error-prone languages Such as C or scripting languages(Instead，you can do all of your server(and client)development in a single development language(No longer does your team need to juggle multiple languages，and cope With the maintainability problems inherent in scripting languages(No longer do your web—based applications need to suffer the performance and portability penalties of CGI(Java is the professional programming tool you need to provide robust server solutions( This section provides you an overview of the key features of Java servlets，addressing these main topics What do Servlets Look Like? Servlet Lifecycle 大连交通大学2016届本科生毕业设计(论文)外文翻译 Security Feature s HTML—Aware Servlets HTTP—Specific Servlets Performance Features What Do Servlets Look Like? Servlets support the familiar programming model of accepting requests and generating responses(This model is used with a variety of distributed system programming toolsets，ranging from remote procedure calls to the HTTP requests made to web servers( Servlets implement the Servlet interface，usually by extending either the generic or an HTTP—specific implementation(The simplest possible servlet defines a single method，service: The service method is provided with Request and Response parameters(These encapsulate fhe data sent by the client，providing access to parameters and allowing servlets to repod status including errors Servlets normally retrieve most of their parameters through an input stream，and send their responses sing an output stream: 、These input and output streams may be used with data(n whatever format is appropriate(For example an applet and service might exchange data using object serialization;HTML，and numerous image formats，may also be appropriate data formats( Servlet and Environment State Since servlets are Java objects，they have instance—specific data(This means that in effect servlets are independent applications running within servers，without needing the complexity of additional classes (Which are required by some alternative server extension APls) Servlets have access to some servlet—specific configuration data at initialization time(This allows different instances of the same servlet class to be initialized with different data, and be managed as differently named servlets(The data provided at initialization time would include an area where each instance would keep its persistent instance—specific state(Servlets also have the ability to interact with 大连交通大学2016届本科生毕业设计(论文)外文翻译 their environment through a ServletContext object( 1ll一 Servlet Lifecycle Servlets are aways dynamically loaded，although servers will usually provide an administrative option to force loading and initializing particular servlets when the server starts up(Servlets are loaded using normal Java class 10ading facilities，which means that they may be loaded from remote directories(for example，a trusted https:,,department,servlets directory)as easily as from the local filesystem(This allows for increased flexibility in system architecture and easier distribution of services in a network( When Are Servlets Loaded? ’ Servers also vary in how they know when to load servlets(When a request comes in，the server knows how to map it to a servlet，which may first need to be loaded(That mapping will usually be done in one 0f these common ways: Server administrators might specify that some kinds of client requests always map to a particular servlet(For example，one which talks to a particular database( Server administrators might specify that part of the client request is the name of the servlet(as Found in an administered servlets directory(At many sites，that directory would be shared between servers which share the load of processing for the site’s clients( Some servers may be able to automatically invoke servlets to filter the output of other servlets based on their administrative configuration(For example，particular types of servlet output may trigger postprocessing by other servlets,perhaps to perform format conversions. Properly authorized clients might specify the servlet which is to be invoked，without administrative intervention( Security Features Servlels have access to information about their clients(When used with secure protocols such as SSL( peer identities can be determined reliably(Servlets relying on HTTP also have access to HTTP-specific authentication data( Servlets have the Java advantage:memory access violations and strong typing violations are not possible,so that faulty servlets will not carvers the way that is common in most C language server extension environment. Unlike any other current server extension API Java Servlets provide strong security policy support(This is because all Java environments provide a Security Manager which can be used to control whether actions such as network or file access are to be permitted(By default，all servlets are untrusted，and are not allowed to perform operations such as accessing network services or local files( However、servlets “built in to” the server,or servlets which have been digitally signed as they were put into Java Archive(JAR)files，may be trusted and granted more permissions by the security manager(A digital signature on executable code indicates that the organization which signed the code” vouches for it”in some sense(Such signatures can’t support accountability by themselves，but they do indicate a 大连交通大学2016届本科生毕业设计(论文)外文翻译 degree of assurance that may be placed on use of that code(For example，a particular signature from a MIS organization might be required on all code which is granted general access to network services within a corporate intranet(That signature might only be used on code which is strongly believed not to violate particular security policies( Web Application Life Cycle A Web application consists of web components，static resource files such as images，and helper classes and libraries. The web container provides many supporting services that enhance the capabilities of web components and make them easier to develop(However，because a web application must take these services into account，the process for creating and running a web application is different from that of traditional stand—alone Java classes(The process for creating，deploying，and executing a web 大连交通大学2016届本科生毕业设计(论文)外文翻译 application can be summarized as follows: 1.Develop the web component code( 2(Develop the web application deployment descriptor( 3. Compile the web application components and helper classes referenced by the components 4?Optionally package the application into a deployable unit( 、 5(Deploy the application into a web container 6. Access a URL that references the web application Web Modules In the Java EE architecture，web components and static web content files such as images are called web resources. A web module is the smallest deployable and usable unit of web resources(A Java EE web module corresponds to a web application as defined in the Java Servlet specification( In addition to web components and web resources，a web module can contain other files 。Server-side utility classes(database beans，shopping carts，and so on)(Often these classes conform to the JavaBeans component architecture( 。 Client—side classes(applets and utility classes)( A web module has a specific structure(The top—level directory of a web module is the document root of the application?The document root is where JSP pages，client-side classes and archives，and static web resources，such as images，are stored( The document root contains a subdirectory named,WEB—INF,，which contains the following files and directories: 。web-xml:The web application deployment descriptor 。Tag library descriptor files(see Tag Library Descriptors，page 220) ?c l a s s e s:A directory that contains server-side classes:servlets，utility classes，and JavaBeans components 。t a g s:A directory that contains tag files，which are implementations of tag libraries(see Tag File Location，page 205) ?lib:A directory that contains JAR archives of libraries called by server-side classes. If your web module does not contain any servlets，filter，or listener components then it does not need a web application deployment descriptor(1n other words，if your web module only contains JSP pages and Static files then you are not required to include a web(Xml file. The h e l l o l example(first discussed in Packaging Web Modules，contains only JSP pages and images and therefore does not include a deployment descriptor You can also create application—specific subdirectories(that is，package directories)in either the 大连交通大学2016届本科生毕业设计(论文)外文翻译 document root or the,WEB—INF,classes,directory A web module can be deployed as an unpacked file structure or can be packaged in a JAR file known as a web archive(WAR)file(Because the contents and use of WAR files differ from those of JAR files(WAR file names use a?war extension(The web module just described is portable;you can deploy it into any Web container that conforms to the Java Servlet Specification( To deploy a WAR on the Application Server，the file must also contain a runtime deployment descriptor( The runtime deployment descriptor is an XML file that contains information such as the context root of the web application and the mapping of the portable names of an application。S resources to the Application Server’s resources(The Application Server web application runtime DD is named sunn—web(xml and is located in,WEB—INF,along with the web application DD( Packaging Web Modules A web module must be packaged into a WAR in certain deployment scenarios and whenever you want to distribute the web module You package a web module into a WAR by executing the J a r command in a directory laid out(n the format of a web module or by using the ant utility(This tutorial allows you to use the second approach(To build the h e l l o l application，follow these steps: In a terminal window，go to ,j avaeetutorial5,examples,web,hell。1,( Run ant(This target will spawn any necessary compilations，copy files to the ,J avaeetutorial5,examples,web,hellol,build, directory，create the WAR file，and copy it to the ,J avaeetutorial5,examples,web,hell01,dist, directory( Deploying a WAR File You can deploy a WAR file to the Application Server in a few ways ? Copying the WAR into the ,domains,domainl,autodeploy,directory ? Using the Admin Console ? By running asadmin or ant to deploy the WAR( All there methods are described briefly in this chapter;however,throughout the tutorial,we use ant for packaging and deploying. Setting the Context Root A context root identifies a wed application in a Java EE server. You sepecify the context root when you deploy a wed module.A context root must start whih a forward slash(/)and end with a string. In a packaget web module for deployment on the Application Server,the cntext root is stored in sun-web.xml. Deploying a Packaget Web Module If you have deployed the hellol application,before proceeding with whis sectiong,undeploy the applicationg by following one of the procedures descrbed in Undeploying Web Modules. Deploying with the Admin Console 1.Expand the Applications node. 2.Select the Web Applicationgs node. 3.Click the Deploy button. 4.Select the radio button labeled"Package file to be upload to the Application Server." 5.Type the full path to the WAR file(or click on Browse to find it),and then click the OK button 6.Click Next. 7.Type the application name. 8.Type the context root. 大连交通大学2016届本科生毕业设计(论文)外文翻译 9.Select the Enabled box. 10.Click the Finish button Deploying with asadmin To deploy a WAR with asadmin,pen a terminal window or command prompt and execute asadmin deploy full-path-to-war-file Deploying with ant To deploy a WAR with ant,open a terminal window or command prompt in the directory where you built and packaged the WAR,and execute ant deploy Testing Deployed Web Modules 中文翻译 Java Servlets的概要 servlet是数据正议定书和平台独立的服务器端组件的集合 Java编写的，动态扩展的Java功能服务器向他们提供了一个总体框架，为服务建成使用提供范式，他们的初步使用，提供Web 基础数据的安全获取，这是介绍了利用HTML网页，你交互式地观看或修改数据用动态网页的技术。由于servlet是运行在服务器内的，他们并不需要一个图形用户界面，否则，他们 :它们是应用组件是下载完成后，对需是服务器端对应应用程序(即只用对客户端的系统) 求，以系统的一部分，这也需要它们图1客户交谈的Java servlet是在servers.clients范围可以在复杂，从简单的HTML 形式，以先进的Java applets.servlets将经常使用的一些种持久性存储，如档案或资料库。 servlet是最常见的组织提供的，提供个性化的多用户服务，以自己的顾客bases.however ， servlet，也有足够的灵活性，以支持标准化服务，如在职静态网页是通过HTTP的(或HTTPS ) 协议 离婚协议模板下载合伙人协议 下载渠道分销协议免费下载敬业协议下载授课协议下载 ，并代理services.since他们用于动态可扩展性，他们可能会用在一个插件，风格独特，配套设施，如搜索发动和半定制applications.servlets还提供强大的平台，为半定制应用，如基于Web的订单输入或存货系统。 尽管所有的servlet是写在Java中，其顾客可以用书面任何language.when servlet是正用在中间层的分布式应用系统，他们可以变成客户其他服务， 写在任何language.for example.servlets可以使用JDBC技术联系的一个应用程序的高度调谐关系型数据库。沟通与其他种电流或遗留系统。可能要类似于要求候补套装软件所要求的那样，这些 制度 关于办公室下班关闭电源制度矿山事故隐患举报和奖励制度制度下载人事管理制度doc盘点制度下载 。 许多方法使用servlet是仅仅是众多申请的servlet是包括一个简单的servlet处理数据被张贴在HTTPS的使用HTML表单中，及其他数据，如采购订单(以信用卡数据) ，这将是一个组成部分，为了进入和处理系统的工作，并一直与产品和库存数据库，并可能设立一个网上支付制 大连交通大学2016届本科生毕业设计(论文)外文翻译 度。 由于servlet是处理多个请求同时，要求能同步相互其他支持协同应用，例如网上会议等功能。人们可以界定一个社会的积极推动者，分享工作中，每个other.the代码每位代理商将被加载作为一个servlet ，以及代理商将通过数据向对方汇报。 一个Servlet的，可以提出要求其他servers.this技术，可以平衡负载中的几个服务器，其中一面镜子，同时content.or ，它可以用来分割一个单一的逻辑服务几间服务器，路由请求，根据任务类型或组织界限。该Java Servlet的含义是一个标准的Java扩展api.this意味着，虽然它不是核心的一部分Java的框架必须始终一部分，所有产品都以Java名称的，它会作出一些支持提供这类产品，由他们将这些厂商作为一个新增功能封装。 Sun公司提供了一套可用于嵌入servlet的支持，在其他网站的服务器，包括阿帕奇(和衍生的服务器，如为支点) 。网景公司FastTrack和企业级服务器，并微软的IIS 。 servlet是最初支持在Java的Web serverfrom sun.since则外，其他一些以Java为基础的网络服务器都支持该API的，或者承诺支持它特色的java.servlet规则。 在Servlet API已经suppoded大多数基于Java的Web伺服器，并implementalions是可用于其他流行的Web servers.this意味着你会得到Java的优势，当你使用在Servlet API不仅将你的代码不会有内存泄露，并受到从硬到找到蠕虫。 您不必锁定自己成为一个单一厂商的服务器扩展的API ，使用容易出错的语言。如C或脚本languages.instead ，你可以做你的全部服务器(和客户端)的发展，在单一的开发language.n请问你的团队必须兼顾多种语文，并配合与可维护性固有的问题，在脚本languages.no不再做你的基于Web 应用需要忍受性能和可携性cgi.java是专业编程工具，你需要提供强有力的伺服器解决 方案 气瓶 现场处置方案 .pdf气瓶 现场处置方案 .doc见习基地管理方案.doc关于群访事件的化解方案建筑工地扬尘治理专项方案下载 。 根据该条的 规定 关于下班后关闭电源的规定党章中关于入党时间的规定公务员考核规定下载规定办法文件下载宁波关于闷顶的规定 ，你概括了主要的功能， Java的servlet是，解决这些问题的主要议题 servlet的样子 Servlet的生命周期 安全功能 HTML是servlet的页面 HTTP的特定对象是servlet 性能特点 servlet是什么, servlet是支持熟悉的编程模型的接受要求，并生成responses.this 模型是用各种各样的分布式系统编程工具，从远程过程打电话给HTTP请求作出Web服务器。 servlet是贯彻落实 大连交通大学2016届本科生毕业设计(论文)外文翻译 Servlet的接口，通常是通过扩大无论是通用或一个HTTP特定implementation.the最简单可行的servlet定义了一个方法，服务:服务方法是提供与要求，并响应parameters.these概括数据派出由客户提供了机会，参数，并允许servlet是为了repod地位，其中包括错误servlet是一般取回他们的大部分参数，通过输入流，并发送他们的反应的输出流: 这些输入和输出流，可用于与data.n什么格式是appropriate.for例子一个Applet与服务，可能交换数据使用对象序列化; HTML及许多形象格式，也可适当的数据格式。 Servlet和环境状况由于servlet是是Java对象，他们有举例具体data.this也就是说，在效果servlet是正独立运行的应用程序内部的服务器，而无需使用复杂性增加的班级。 (这是需要一些替代服务器延伸对Servlet的使用) servlet是已进入某些Servlet的具体配置数据，在初始化time.this允许不同的事例，同时Servlet的级别被初始化不同的数据，并加以管理不同名称servlets.the提供的数据，在初始化的时候将包括一个领域，每个举例来说，将保持其持久性，例如特定state.servlets也有能力进行互动他们的环境，通过ServletContext中的物体。 servlet是已进入某些Servlet的具体配置数据，在初始化time.this允许不同的事例，同时Servlet的班级被初始化不同的数据，并加以管理不同名称servlets.the提供的数据，在初始化的时候将包括一个领域，每个举例来说，将保持其持久性，例如特定state.servlets也有能力进行互动他们的环境，通过ServletContext中的的语句。 什么是servlet, ' 服务器也各有不同，他们如何知道什么时候负荷servlets.when请求进来时，服务器知道如何绘制它以一个servlet ，它可能必须先予以loaded.that映射通常会做一取消，这些常见的方式: 服务器管理员可以指定一些类型的客户的要求，始终地图某一servlet.for举一个例子，其中会谈到一个特定的数据库。 服务器管理员可能会指明这部分的客户的要求是名字的servlet.as 发现一个经管servlet是directory.at许多网站，该目录将分担服务器分担负载的处理，为现场的客户。 有些伺服器或许能够自动调用servlet是过滤输出的其他servlet是根据他们的行政configuration.for例如，特定类型的Servlet的产量就可能触发后处理，由其他servlet是，或许履行格式转换。 适当授权客户可指定的servlet是被引用过，在没有行政干预。防伪特征servlels有机会获得信息约其clients.when使用安全协议，如SSL了。 同行的身份可以判定reliably.servlets依靠HTTP的，也有进入的HTTP特定认证数据。 servlet是有Java的优势:记忆体存取行为，并有强烈的延续行为。错误的servlet是不会 大连交通大学2016届本科生毕业设计(论文)外文翻译 雕刻的手法是，在大部分C语言服务器扩建环境。 不同于其它任何当前服务器扩展API的Java servlet是提供强有力的安全策略support.this 是因为所有的Java环境提供一个安全限制可以用来控制是否将行动，例如网络或文件访问，以permitted.by默认情况下，所有servlet是不可信的，并不得执行操作，如存取网络服务或本地文件。 不过， servlet是"建在"服务器内部或servlet是已进行数字签名，因为他们把到Java进程的档案，可能会受到信任和给予更多的权限，由保安manager.a 数字签名就可执行代码表明，该组织的出现就意味 "先天不足，加上管理松散它"在一些sense.such签名，不能够支持问责制本身，但他们的确显示一定程度的保证，将被放置在使用该code.for举例来说，某一特定签字，从MIS的组织可能需要的所有守则，这是理所当然的一般接触网络服务在一个企业intranet.that签名可能只用于守则，这是强烈认为，不特别是对违反安全政策。 Web应用的生命周期 一个网络应用软件的网页元件，静态资源文件，如影像，并帮手班和图书馆。该Web容器提供了许多配套服务，致力提升能力的网络组件，使它们更容易develop.however ，因为一个Web应用程序必须考虑这些服务到，这一过程，为创建和运行Web应用是不同的是传统的独立的Java classes.the过程中，用于创建，部署和执行一个网站应用可归纳如下: 1.发展了Web组件代码。 2.扩展了 Web应用部署描述符。 3 编译Web应用组件和helper类参照由组件四可选包申请成为伸展单元， 5.扩展并应用到Web容器 6 获得一个URL ，提及Web应用 网络模块 在Java EE的架构， Web组件和静态网页内容的文件，如图像称为Web 的资源。一个网络模块是最小的部署和使用单位的网站resources.a Java EE的网站单元对应一个web应用作为定义在Java Servlet的 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 。 此外，以Web组件和网络资源，网络模块可包含其他文件。 服务器端实用班(数据库类等) 。通常，这些符合需要JavaBeans组件体系结构。客户端( applets的和公用事业)。 一个网络模块中有一个特定的结构最高层的目录中的一个网络的模块是文件的根申请文件的根是JSP页面，客户端和档案，以及静态网页资源，如图像，储存。 该文件根包含一个子目录命名/网络-干扰素/ ，其中含有下列档案和目录: 网上的XML : Web应用部署描述符。标签库描述符文件(见标签库描述符，页220 ) 一个目录，它包含了服务器端的班: servlet是，实用课程，JavaBeans的组件标签:一个目录，它 大连交通大学2016届本科生毕业设计(论文)外文翻译 包含了标签文件，这是实现标签库(见标签文件位置，第205页)一个目录包含子文件，由服务器中转。 如果您的Web模块不包含任何servlet是，过滤或听众组成部分，然后它不需要Web应用部署descriptor.1n换言之，如果您的Web模块只包含JSP页面和静态档案，那你就没有必要加入一个web.xml文件。example.first 讨论在包装网络模块，只含有JSP页面和图像，因此不包括部署描述符。 您也可以创建特定应用子目录(也就是包目录) ，无论文件根或/网络-干扰素/班/目录一个网络模块可部署作为散装文件结构或可以装在文件称为网路档案file.because内容和使用网络档案不同于这些files.war 档案名称使用extension.the网络模块刚才所描述的是便携式的，你可以调配成任何Web容器符合该Java Servlet的规范。 部署一个网络文件的对应用服务器，则该文件还必须包含运行时部署描述符。 运行时部署描述符是一个XML文件，包含资料，如背景根本的Web应用，并绘制了便携式的名字申请。保安局资源，以应用服务器上的资源的应用服务器Web应用程序运行时命名sunn - web.xml中并位于/网络-干扰素/随着Web应用。 包装网路模组 一个网络模块，必须将它包装成模块组，在某些部署方案，每当你想分销网络模块，您要包装一个网络模块成为一个程序的执行了网络在目录奠定out.n格式的一个网络模块或用零碎的utility.this补习可以让你用第二approach.to建设hellol申请时，依照下列步骤进行: 在一个终端窗口， ,j avaeetutorial5,examples,web,hell。1,( Run ant(This target will spawn any necessary compilations，copy files to the ,J avaeetutorial5,examples,web,hellol,build, directory，create the WAR file，and copy it to the ,J avaeetutorial5,examples,web,hell01,dist, 部署档案 你可以部署一个档案文件到应用服务器的几个方法: ? Copying the WAR into the ,domains,domainl,autodeploy,directory ? Using the Admin Console ? By running asadmin or ant to deploy the WAR( 一切有法的基本原理，所有的程序都有一定的规则，简单地在这一章中，但在整个补习，我们用分散的作包装和部署设置上下文根路径。 部署packaget网络模块 如果消费者已经部署了hellol应用，然后才继续进行whis sectiong ， undeploy了applicationg按下列程序之一， descrbed在undeploying网络模块。 部署与管理控制台 大连交通大学2016届本科生毕业设计(论文)外文翻译 1.expand申请节点。 2.select网上applicationgs节点。 点选了部署按钮。 4.select单选按钮标记的"一揽子文件被上传到应用服务器" 。 5.type全路径有关战争的档案(或单击浏览以找到) ，然后点击OK按钮 6.click未来。 7.type应用程序的名称。 8.在一定规律下利用不同类型的方法进行检查。 9.内部查询。 10.点击完成按钮 部署与asadmin 部署一个整体数据与asadmin ，用笔一个终端窗口或命令提示符并执行asadmin部署全路至整体档案部署与分散部署一个整体和局部，打开一个终端窗口或命令提示符在目录中，您建成和包装整体数据，并执行分散部署测试部署的Web模块 拥有的只是对数组的引用，没有给数组分配存储空间，要写初始化表达式。初始化动作可以在代码的任何地方。用一对花括号只能在创建数组的地方出现。java标准类库Arrays也有fill()方法，但是只能用同一个值填充各个位置，对于保存对象的数组，就是复制同一个引用进行填充。数组标识符只是一个引用，指向在堆heap中创建的一个真实对象，这个数组对象用以保存指向其他对象的引用。对象数组和基本数据类型数组在使用上基本一致，不同在于对象数组保存的是引用，基本类型数组直接保存基本类型。