JSTL SPECIFICATION PDF
Implementors of JSTL and authors of JSP pages may find the The JavaServer Pages™ Standard Tag Library (JSTL) specification is the result. The JavaServer Pages Standard Tag Library (JSTL) is a component of the Java EE Web application development platform. It extends the JSP specification by. Apache hosts the Apache Standard Taglib, an implementation of the JSP Standard Tag Library (JSTL) specification. Various versions are.
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As touched on briefly in the first chapter, this is one of the most important features of the JSTL and is a prominent feature of the JSP 2. Locale and resource bundles that include such actions as: What it means to use EL in attributes can be shown in the following example:. Using the implicit objects param and paramValues, it is also possible to access HTTP request parameters. In this example, we would be accessing a variable already set, called userNameStringthat would then be used as a parameter to the message.
To sum up for now, the layout of the JSTL is straightforward.
If the identifier isn’t found in any scope, then a null value is returned. The specification can be found at http: These objects allow for access to any variables that are held in the particular JSP scopes. There are four general-purpose tags. The book has just been released and comes with free download of all code examples used throughout.
Using separate TLDs to expose the tags, the functionality for each set of actions is apparent and makes more sense. To address both of these functional areas, let’s first take a cursory look at what pieces are involved in creating international applications. The following sections are excerpted from various chapters within the JSTL: It defaults to true. Let’s look at each functional section in the Core tag library a bit more closely.
Psecification then go through the other configuration settings as well as the available interfaces. General-purpose actions that are used to manipulate the scoped variables that might be found within a JSP. No more creating specificattion own iteration action for the tenth time.
JavaServer Pages Standard Tag Library
The automatic type conversion is a very convenient feature of the EL in that a full set of coercion between various object and primitive types is supported. In another example, we might want to output some data values that have been stored in a scoped variable called myData.
The first output is using the default value of escapeXmlwhile the second output shows the result of using the esacpeXml set to false. Have you heard about the JSTL but aren’t quite sure of how to make the best use of it?
Each standard action is covered with a detailed explanation and includes a code sample so you can start using the JSTL immediately. The JSTL includes a number of actions that provide a mechanism for interacting with databases. The previous sentence should, at a very minimum, send up a red flag in your architectural visions. Conditional actions used for doing conditional processing within a JSP.
If you are careful about how you code your SQL actions, it should be easy enough to pull out the code and put it into classes that represent the Model interaction at a later point.
Let’s walk through code samples to see how we use each of the tags provided in this library. We will talk about this in more detail later in this chapter, but as a quick example, so that you are familiar with the format, the action might look like: Using the Expression Language Before we dive into the various functional areas in the JSTL, we should start with the expression language.
Again, this is as if you had made ServletRequest. Using separate TLDs to expose the tags, the functionality for each set of actions is apparent and makes more. Automatic Type Conversion The automatic type conversion is a very convenient feature of the EL in that a full set of coercion between various object and primitive types is supported.
JSR A Standard Tag Library for JavaServer Pages(TM) Specification Maintenance Release 2
Struts is an MVC framework that can be learned quickly and will provide a much cleaner architecture than having Model information located throughout your JSPs. The I18N functional area can be broken down into two main areas: For example, a String parameter from a request will be coerced to the appropriate object or primitive. With escapeXml set to false:. These actions come under specifictaion functionality of the I18N umbrella.
Writing Output specificatikn the JspWriter There are four general-purpose tags.
The two displays are shown as they would appear if you were to view the source of the resulting file in your browser. This means that you don’t want it in your JSPs. Formatting for numbers, dates, and currency, which includes such actions as: Keep in mind that when using an identifier like book ,for example with the EL, it is the same thing as if you had done PageContext. To follow a Model-View. Wouldn’t it be great if the effort required to internationalize your application could be reduced to zero?
There are quite a few implicit objects exposed through the EL. The XML entity values that are used for encoding the characters are shown in Table 4.
This dilemma is what has hampered the true role separation between the JSP page author and the Java programmer.