All Packages from javax.servlet.http.* to javax.servlet.jsp.*

Home >> All >> javax >> [ servlet Javadoc ]

•

• javax.servlet: Javadoc index of package javax.servlet.

Package Samples:

• javax.servlet.http: The javax.servlet package contains a number of classes and interfaces that describe and define the contracts between a servlet class and the runtime environment provided for an instance of such a class by a conforming servlet container.
• javax.servlet.jsp.tagext: Classes and interfaces for the Core JSP 2.0 API.
• javax.servlet.jsp.el: Classes and interfaces for the Core JSP 2.0 API.
• javax.servlet.jsp
• javax.servlet.jsp.jstl.core
• javax.servlet.jsp.jstl.fmt
• javax.servlet.jsp.jstl.sql
• javax.servlet.jsp.jstl.tlv

Classes:

• VariableInfo: Information on the scripting variables that are created/modified by a tag (at run-time). This information is provided by TagExtraInfo classes and it is used by the translation phase of JSP. Scripting variables generated by a custom action have an associated scope of either AT_BEGIN, NESTED, or AT_END. The class name (VariableInfo.getClassName) in the returned objects is used to determine the types of the scripting variables. Note that because scripting variables are assigned their values from scoped attributes which cannot be of primitive types, "boxed" types such as java.lang.Integer ...
• BodyTag: The BodyTag interface extends IterationTag by defining additional methods that let a tag handler manipulate the content of evaluating its body. It is the responsibility of the tag handler to manipulate the body content. For example the tag handler may take the body content, convert it into a String using the bodyContent.getString method and then use it. Or the tag handler may take the body content and write it out into its enclosing JspWriter using the bodyContent.writeOut method. A tag handler that implements BodyTag is treated as one that implements IterationTag, except that the doStartTag method ...
• Tag: The interface of a classic tag handler that does not want to manipulate its body. The Tag interface defines the basic protocol between a Tag handler and JSP page implementation class. It defines the life cycle and the methods to be invoked at start and end tag. Properties The Tag interface specifies the setter and getter methods for the core pageContext and parent properties. The JSP page implementation object invokes setPageContext and setParent, in that order, before invoking doStartTag() or doEndTag(). Methods There are two main actions: doStartTag and doEndTag. Once all appropriate properties ...
• JspWriter: The actions and template data in a JSP page is written using the JspWriter object that is referenced by the implicit variable out which is initialized automatically using methods in the PageContext object. This abstract class emulates some of the functionality found in the java.io.BufferedWriter and java.io.PrintWriter classes, however it differs in that it throws java.io.IOException from the print methods while PrintWriter does not. Buffering The initial JspWriter object is associated with the PrintWriter object of the ServletResponse in a way that depends on whether the page is or is not buffered. ...
• PageContext: PageContext extends JspContext to provide useful context information for when JSP technology is used in a Servlet environment. A PageContext instance provides access to all the namespaces associated with a JSP page, provides access to several page attributes, as well as a layer above the implementation details. Implicit objects are added to the pageContext automatically. The PageContext class is an abstract class, designed to be extended to provide implementation dependent implementations thereof, by conformant JSP engine runtime environments. A PageContext instance is obtained by a JSP implementation ...
• TagLibraryValidator: Translation-time validator class for a JSP page. A validator operates on the XML view associated with the JSP page. The TLD file associates a TagLibraryValidator class and some init arguments with a tag library. The JSP container is reponsible for locating an appropriate instance of the appropriate subclass by new a fresh instance, or reuse an available one invoke the setInitParams(Map) method on the instance once initialized, the validate(String, String, PageData) method will be invoked, where the first two arguments are the prefix and uri for this tag library in the XML View. The prefix is intended ...
• SimpleTag: Interface for defining Simple Tag Handlers. Simple Tag Handlers differ from Classic Tag Handlers in that instead of supporting doStartTag() and doEndTag() , the SimpleTag interface provides a simple doTag() method, which is called once and only once for any given tag invocation. All tag logic, iteration, body evaluations, etc. are to be performed in this single method. Thus, simple tag handlers have the equivalent power of BodyTag , but with a much simpler lifecycle and interface. To support body content, the setJspBody() method is provided. The container invokes the setJspBody() method with a ...
• HttpSession: Provides a way to identify a user across more than one page request or visit to a Web site and to store information about that user. The servlet container uses this interface to create a session between an HTTP client and an HTTP server. The session persists for a specified time period, across more than one connection or page request from the user. A session usually corresponds to one user, who may visit a site many times. The server can maintain a session in many ways such as using cookies or rewriting URLs. This interface allows servlets to View and manipulate information about a session, such ...
• IterationTag: The IterationTag interface extends Tag by defining one additional method that controls the reevaluation of its body. A tag handler that implements IterationTag is treated as one that implements Tag regarding the doStartTag() and doEndTag() methods. IterationTag provides a new method: doAfterBody() . The doAfterBody() method is invoked after every body evaluation to control whether the body will be reevaluated or not. If doAfterBody() returns IterationTag.EVAL_BODY_AGAIN, then the body will be reevaluated. If doAfterBody() returns Tag.SKIP_BODY, then the body will be skipped and doEndTag() will ...
• ServletResponse: Defines an object to assist a servlet in sending a response to the client. The servlet container creates a ServletResponse object and passes it as an argument to the servlet's service method. To send binary data in a MIME body response, use the ServletOutputStream returned by getOutputStream() 55 . To send character data, use the PrintWriter object returned by getWriter() 55 . To mix binary and text data, for example, to create a multipart response, use a ServletOutputStream and manage the character sections manually. The charset for the MIME body response can be specified explicitly using the ...
• Cookie: Creates a cookie, a small amount of information sent by a servlet to a Web browser, saved by the browser, and later sent back to the server. A cookie's value can uniquely identify a client, so cookies are commonly used for session management. A cookie has a name, a single value, and optional attributes such as a comment, path and domain qualifiers, a maximum age, and a version number. Some Web browsers have bugs in how they handle the optional attributes, so use them sparingly to improve the interoperability of your servlets. The servlet sends cookies to the browser by using the HttpServletResponse.addCookie(javax.servlet.http.Cookie) ...
• LoopTagSupport: Base support class to facilitate implementation of iteration tags. Since most iteration tags will behave identically with respect to actual iterative behavior, JSTL provides this base support class to facilitate implementation. Many iteration tags will extend this and merely implement the hasNext() and next() methods to provide contents for the handler to iterate over. In particular, this base class provides support for: Iteration control, based on protected prepare() , next() , and hasNext() methods Subsetting ( begin , end , step> functionality, including validation of subset parameters for sensibility) ...
• JspContext: JspContext serves as the base class for the PageContext class and abstracts all information that is not specific to servlets. This allows for Simple Tag Extensions to be used outside of the context of a request/response Servlet. The JspContext provides a number of facilities to the page/component author and page implementor, including: a single API to manage the various scoped namespaces a mechanism to obtain the JspWriter for output a mechanism to expose page directive attributes to the scripting environment Methods Intended for Container Generated Code The following methods enable the management ...
• JspPage: The JspPage interface describes the generic interaction that a JSP Page Implementation class must satisfy; pages that use the HTTP protocol are described by the HttpJspPage interface. Two plus One Methods The interface defines a protocol with 3 methods; only two of them: jspInit() and jspDestroy() are part of this interface as the signature of the third method: _jspService() depends on the specific protocol used and cannot be expressed in a generic way in Java. A class implementing this interface is responsible for invoking the above methods at the appropriate time based on the corresponding Servlet-based ...
• HttpServlet: Provides an abstract class to be subclassed to create an HTTP servlet suitable for a Web site. A subclass of HttpServlet must override at least one method, usually one of these: doGet , if the servlet supports HTTP GET requests doPost , for HTTP POST requests doPut , for HTTP PUT requests doDelete , for HTTP DELETE requests init and destroy , to manage resources that are held for the life of the servlet getServletInfo , which the servlet uses to provide information about itself There's almost no reason to override the service method. service handles standard HTTP requests by dispatching them to ...
• JspFragment: Encapsulates a portion of JSP code in an object that can be invoked as many times as needed. JSP Fragments are defined using JSP syntax as the body of a tag for an invocation to a SimpleTag handler, or as the body of a <jsp:attribute> standard action specifying the value of an attribute that is declared as a fragment, or to be of type JspFragment in the TLD. The definition of the JSP fragment must only contain template text and JSP action elements. In other words, it must not contain scriptlets or scriptlet expressions. At translation time, the container generates an implementation of the ...
• TagExtraInfo: Optional class provided by the tag library author to describe additional translation-time information not described in the TLD. The TagExtraInfo class is mentioned in the Tag Library Descriptor file (TLD). This class can be used: to indicate that the tag defines scripting variables to perform translation-time validation of the tag attributes. It is the responsibility of the JSP translator that the initial value to be returned by calls to getTagInfo() corresponds to a TagInfo object for the tag being translated. If an explicit call to setTagInfo() is done, then the object passed will be returned ...
• Servlet: Defines methods that all servlets must implement. A servlet is a small Java program that runs within a Web server. Servlets receive and respond to requests from Web clients, usually across HTTP, the HyperText Transfer Protocol. To implement this interface, you can write a generic servlet that extends javax.servlet.GenericServlet or an HTTP servlet that extends javax.servlet.http.HttpServlet . This interface defines methods to initialize a servlet, to service requests, and to remove a servlet from the server. These are known as life-cycle methods and are called in the following sequence: The servlet ...
• ExpressionEvaluator: The abstract base class for an expression-language evaluator. Classes that implement an expression language expose their functionality via this abstract class. An instance of the ExpressionEvaluator can be obtained via the JspContext / PageContext The parseExpression() and evaluate() methods must be thread-safe. That is, multiple threads may call these methods on the same ExpressionEvaluator object simultaneously. Implementations should synchronize access if they depend on transient state. Implementations should not, however, assume that only one object of each ExpressionEvaluator type will be ...
• UnavailableException: Defines an exception that a servlet or filter throws to indicate that it is permanently or temporarily unavailable. When a servlet or filter is permanently unavailable, something is wrong with it, and it cannot handle requests until some action is taken. For example, a servlet might be configured incorrectly, or a filter's state may be corrupted. The component should log both the error and the corrective action that is needed. A servlet or filter is temporarily unavailable if it cannot handle requests momentarily due to some system-wide problem. For example, a third-tier server might not be accessible, ...
• SQLExecutionTag: This interface allows tag handlers implementing it to receive values for parameter markers in their SQL statements. This interface is implemented by both <sql:query> and <sql:update>. Its addSQLParameter() method is called by nested parameter actions (such as <sql:param>) to substitute PreparedStatement parameter values for "?" parameter markers in the SQL statement of the enclosing SQLExecutionTag action. The given parameter values are converted to their corresponding SQL type (following the rules in the JDBC specification) before they are sent to the database. Keeping track ...
• ServletContext: Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file. There is one context per "web application" per Java Virtual Machine. (A "web application" is a collection of servlets and content installed under a specific subset of the server's URL namespace such as /catalog and possibly installed via a .war file.) In the case of a web application marked "distributed" in its deployment descriptor, there will be one context instance for each virtual machine. In this situation, the context ...
• BodyContent: An encapsulation of the evaluation of the body of an action so it is available to a tag handler. BodyContent is a subclass of JspWriter. Note that the content of BodyContent is the result of evaluation, so it will not contain actions and the like, but the result of their invocation. BodyContent has methods to convert its contents into a String, to read its contents, and to clear the contents. The buffer size of a BodyContent object is unbounded. A BodyContent object cannot be in autoFlush mode. It is not possible to invoke flush on a BodyContent object, as there is no backing stream. Instances ...
• SingleThreadModel: Ensures that servlets handle only one request at a time. This interface has no methods. If a servlet implements this interface, you are guaranteed that no two threads will execute concurrently in the servlet's service method. The servlet container can make this guarantee by synchronizing access to a single instance of the servlet, or by maintaining a pool of servlet instances and dispatching each new request to a free servlet. Note that SingleThreadModel does not solve all thread safety issues. For example, session attributes and static variables can still be accessed by multiple requests on multiple ...
• ValidationMessage: A validation message from either TagLibraryValidator or TagExtraInfo. As of JSP 2.0, a JSP container must support a jsp:id attribute to provide higher quality validation errors. The container will track the JSP pages as passed to the container, and will assign to each element a unique "id", which is passed as the value of the jsp:id attribute. Each XML element in the XML view available will be extended with this attribute. The TagLibraryValidator can then use the attribute in one or more ValidationMessage objects. The container then, in turn, can use these values to provide more precise information ...

Home | Contact Us | Privacy Policy | Terms of Service