JavaServer Pages Pocket Reference: Server-Side Java Development

Free download. Book file PDF easily for everyone and every device. You can download and read online JavaServer Pages Pocket Reference: Server-Side Java Development file PDF Book only if you are registered here. And also you can download or read online all Book PDF file that related with JavaServer Pages Pocket Reference: Server-Side Java Development book. Happy reading JavaServer Pages Pocket Reference: Server-Side Java Development Bookeveryone. Download file Free Book PDF JavaServer Pages Pocket Reference: Server-Side Java Development at Complete PDF Library. This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats. Here is The CompletePDF Book Library. It's free to register here to get Book file PDF JavaServer Pages Pocket Reference: Server-Side Java Development Pocket Guide.

The JspWriter emulates java. PrintWriter , but supports buffering like java. The usual java. PrintWriter methods are available with the modification that the JspWriter methods throw java. A JSP author infrequently references the out object directly. The most common use is within a scriptlet or as a parameter passed to another method. For example, the code below uses out object to print "Example of out implicit object" on the JSP:. The request object is a standard servlet object that is a protocol-dependent subclass of javax.

In other words, for the HTTP protocol, the request object is an instance of javax. The request object provides access to details regarding the request and requester. For example, the code below fetches the value of the request parameter named username:. The response object is a standard servlet object that is a protocol-dependent subclass of javax.

For the HTTP protocol, the response object is an instance of javax. The response object provides access to the servlet output stream. It also allows you to set response headers, including cookies, content type, cache control, refresh, and redirection, and it supports URL encoding as an aid to session tracking when cookies aren't available. The session object is a standard servlet object that is an instance of the javax. HttpSession class.


  • The Story of Mormonism.
  • About This Item.
  • What is JSP? Introduction to JavaServer Pages?
  • An Eposition on the Power of the Islamic Religion.
  • MESSAGES: FLOWING WITH SYNCHRONICITY.
  • Blitzcat.
  • JavaServer Pages Pocket Reference - O'Reilly Media!

This object helps support the illusion of a client session within the HTTP protocol. JSP authors essentially get sessions for free. Simply use session scope when using jsp:useBean to work with any session-specific beans.


  • JavaServer Pages Pocket Reference - O'Reilly Media?
  • Books & Videos.
  • Books & Videos.
  • BE THE FIRST TO KNOW!
  • JavaServer Pages Pocket Reference: Server-Side Java Development - Hans Bergsten - Google книги.
  • And The Last Went First?

The pageContext object is an instance of javax. The pageContext object provides a uniform access method to the various JSP objects and beans, regardless of scope. It also provides the means through which the out object is acquired, so an implementation can supply a custom JspWriter , and provides the JSP interface to include and forward functionality. As shown below, you can also use pageContext to set attributes or to fetch exceptions and process as required:.

The config object is a standard servlet object that is an instance of the javax. ServletConfig class. It provides access to the ServletContext and to any servlet initialization parameters. You'll rarely use this object.

javaserver pages pocket reference server side java development Manual

As discussed in The JspPage interface , the page object is a javax. JspPage interface descendent. As you saw in the jspInit and jspDestroy example , you might declare the jspInit and jspDestroy methods. The application object is a standard servlet object that is an instance of the javax. ServletContext class. You also use ServletContext to get the RequestDispatcher. The exception object is an instance of java. The exception object is present only in an error page, defined as such by the page directive.

JavaServer Pages Pocket Reference: Server-Side Java Development

It is recommended that application behavior be encapsulated in objects whenever possible. This helps page designers focus on the presentation issues. Apart from the predefined implicit objects, a JSP can access, create, and modify server-side objects. You can create and use objects within a JSP in many ways:. Scope describes what entities can access the object.

Objects can be defined in any of the following scopes:. All references to such an object are released after the JSP sends the response back to the client or the request is forwarded somewhere else. References to objects with page scope are stored in the pageContext object. References to the object are released after the request processes.

In particular, if the request is forwarded to a resource in the same runtime, the object is still reachable. References to objects with request scope are stored in the request object. It is illegal to define an object with session scope from within a page that is not session-aware. All references to the object are released after the associated session ends. The application object is the servlet context obtained from the servlet configuration object.

Expression language is used for run-time assignment of values to action element attributes. Now, as an integral part of the JSP 2.

Java Server-Side Programming

Expression language is inspired by both ECMAScript and XPath expression languages, and uses the features of both languages, as well as introduces some new ones. For example, expression language performs data-type conversions automatically. You can do this through the configuration element scripting-invalid. As discussed in JSP configuration , making the value of this element true allows the use of expression language, but prohibits the user from using Java scriptlets, Java expressions, or Java declaration elements within JSPs.

Let's consider an example detailing the use of implicit objects. The table below describes how you can access and resolve information like request attributes, session attributes, and request parameters first column of the table using EL second column of the table. The third column displays the result of the resolution. Expression language can use the following five arithmetic operators to act on integer and floating point values:. Relational operators operate on two operands and always return a boolean result. You can use the following relational operators with EL:.

Logical operators operate on two expressions and always return a boolean value. Expression language can use the following logical operators:.

Writing JSP pages

This operator is used for conditional processing. Depending on the boolean result of the condition, one of the two possible results is returned. As discussed above, you use [] and. Let's consider an example where customer is the name of a bean with property SSN. The value within the brackets must be a string literal for the property's name or a variable that holds the property's name. Actions provide a higher level of functionality than the declarations, expressions, and scriptlets you've seen thus far.

Javaserver Pages Pocket Reference: Server-side Java Development

Unlike the scripting elements, actions are independent of any scripting language. In many respects, JSP actions are like built-in custom tags. Also, JSP 2. For a complete discussion of tag files, refer to Tag files. The jsp:useBean , jsp:setProperty , and jsp:getProperty actions work together to achieve this integration. Although a full treatment of the JavaBeans component architecture is outside this tutorial's scope, it is easy to explain the essential convention required to interact with jsp:useBean , jsp:setProperty , and jsp:getProperty.

For any given value called a property of type T named N you want to make settable, the class must have a method whose signature is:. For any given property of type T named N you want to make gettable, the class must have a method whose signature is:. You also provide creation information. The JSP checks to see if a bean of that name and scope already exists. If not, the bean is instantiated and registered. If the bean needs to be created and you use the second form of jsp:useBean , the statements that make up the creation-body are also executed.

The object made available by useBean is also known as a scripting variable and is available to other scripting elements within the JSP invoking jsp:useBean. The jsp:useBean action makes the bean available as a scripting variable available within the page, but what is the overall lifespan of the bean? Is it recreated each time? Is there a unique copy of the bean for each session? That is the purpose of the scope attribute. The bean remains available throughout the lifetime of the specified scope, which must be one of the following:. The bean-specification attributes are extremely flexible and cover a wide range of options, as illustrated by the following table.

The jsp:setProperty action is a high-level, scripting-language-independent method for setting the values of a scripting variable.