Methods Summary |
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public java.lang.Object | getAttribute(java.lang.String name)Returns the servlet container attribute with the given name,
or null if there is no attribute by that name.
An attribute allows a servlet container to give the
servlet additional information not
already provided by this interface. See your
server documentation for information about its attributes.
A list of supported attributes can be retrieved using
getAttributeNames .
The attribute is returned as a java.lang.Object
or some subclass.
Attribute names should follow the same convention as package
names. The Java Servlet API specification reserves names
matching java.* , javax.* ,
and sun.* .
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public java.util.Enumeration | getAttributeNames()Returns an Enumeration containing the
attribute names available
within this servlet context. Use the
{@link #getAttribute} method with an attribute name
to get the value of an attribute.
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public javax.servlet.ServletContext | getContext(java.lang.String uripath)Returns a ServletContext object that
corresponds to a specified URL on the server.
This method allows servlets to gain
access to the context for various parts of the server, and as
needed obtain {@link RequestDispatcher} objects from the context.
The given path must be begin with "/", is interpreted relative
to the server's document root and is matched against the context roots of
other web applications hosted on this container.
In a security conscious environment, the servlet container may
return null for a given URL.
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public java.lang.String | getContextPath()Returns the context path of the web application.
The context path is the portion of the request URI that is used
to select the context of the request. The context path always comes
first in a request URI. The path starts with a "/" character but does
not end with a "/" character. For servlets in the default (root)
context, this method returns "".
It is possible that a servlet container may match a context by
more than one context path. In such cases the
{@link javax.servlet.http.HttpServletRequest#getContextPath()}
will return the actual context path used by the request and it may
differ from the path returned by this method.
The context path returned by this method should be considered as the
prime or preferred context path of the application.
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public java.lang.String | getInitParameter(java.lang.String name)Returns a String containing the value of the named
context-wide initialization parameter, or null if the
parameter does not exist.
This method can make available configuration information useful
to an entire "web application". For example, it can provide a
webmaster's email address or the name of a system that holds
critical data.
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public java.util.Enumeration | getInitParameterNames()Returns the names of the context's initialization parameters as an
Enumeration of String objects, or an
empty Enumeration if the context has no initialization
parameters.
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public int | getMajorVersion()Returns the major version of the Java Servlet API that this
servlet container supports. All implementations that comply
with Version 2.5 must have this method
return the integer 2.
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public java.lang.String | getMimeType(java.lang.String file)Returns the MIME type of the specified file, or null if
the MIME type is not known. The MIME type is determined
by the configuration of the servlet container, and may be specified
in a web application deployment descriptor. Common MIME
types are "text/html" and "image/gif" .
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public int | getMinorVersion()Returns the minor version of the Servlet API that this
servlet container supports. All implementations that comply
with Version 2.5 must have this method
return the integer 5.
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public javax.servlet.RequestDispatcher | getNamedDispatcher(java.lang.String name)Returns a {@link RequestDispatcher} object that acts
as a wrapper for the named servlet.
Servlets (and JSP pages also) may be given names via server
administration or via a web application deployment descriptor.
A servlet instance can determine its name using
{@link ServletConfig#getServletName}.
This method returns null if the
ServletContext
cannot return a RequestDispatcher for any reason.
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public java.lang.String | getRealPath(java.lang.String path)Returns a String containing the real path
for a given virtual path. For example, the path "/index.html"
returns the absolute file path on the server's filesystem would be
served by a request for "http://host/contextPath/index.html",
where contextPath is the context path of this ServletContext..
The real path returned will be in a form
appropriate to the computer and operating system on
which the servlet container is running, including the
proper path separators. This method returns null
if the servlet container cannot translate the virtual path
to a real path for any reason (such as when the content is
being made available from a .war archive).
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public javax.servlet.RequestDispatcher | getRequestDispatcher(java.lang.String path)Returns a {@link RequestDispatcher} object that acts
as a wrapper for the resource located at the given path.
A RequestDispatcher object can be used to forward
a request to the resource or to include the resource in a response.
The resource can be dynamic or static.
The pathname must begin with a "/" and is interpreted as relative
to the current context root. Use getContext to obtain
a RequestDispatcher for resources in foreign contexts.
This method returns null if the ServletContext
cannot return a RequestDispatcher .
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public java.net.URL | getResource(java.lang.String path)Returns a URL to the resource that is mapped to a specified
path. The path must begin with a "/" and is interpreted
as relative to the current context root.
This method allows the servlet container to make a resource
available to servlets from any source. Resources
can be located on a local or remote
file system, in a database, or in a .war file.
The servlet container must implement the URL handlers
and URLConnection objects that are necessary
to access the resource.
This method returns null
if no resource is mapped to the pathname.
Some containers may allow writing to the URL returned by
this method using the methods of the URL class.
The resource content is returned directly, so be aware that
requesting a .jsp page returns the JSP source code.
Use a RequestDispatcher instead to include results of
an execution.
This method has a different purpose than
java.lang.Class.getResource ,
which looks up resources based on a class loader. This
method does not use class loaders.
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public java.io.InputStream | getResourceAsStream(java.lang.String path)Returns the resource located at the named path as
an InputStream object.
The data in the InputStream can be
of any type or length. The path must be specified according
to the rules given in getResource .
This method returns null if no resource exists at
the specified path.
Meta-information such as content length and content type
that is available via getResource
method is lost when using this method.
The servlet container must implement the URL handlers
and URLConnection objects necessary to access
the resource.
This method is different from
java.lang.Class.getResourceAsStream ,
which uses a class loader. This method allows servlet containers
to make a resource available
to a servlet from any location, without using a class loader.
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public java.util.Set | getResourcePaths(java.lang.String path)Returns a directory-like listing of all the paths to resources within the web application whose longest sub-path
matches the supplied path argument. Paths indicating subdirectory paths end with a '/'. The returned paths are all
relative to the root of the web application and have a leading '/'. For example, for a web application
containing
/welcome.html
/catalog/index.html
/catalog/products.html
/catalog/offers/books.html
/catalog/offers/music.html
/customer/login.jsp
/WEB-INF/web.xml
/WEB-INF/classes/com.acme.OrderServlet.class,
getResourcePaths("/") returns {"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"}
getResourcePaths("/catalog/") returns {"/catalog/index.html", "/catalog/products.html", "/catalog/offers/"}.
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public java.lang.String | getServerInfo()Returns the name and version of the servlet container on which
the servlet is running.
The form of the returned string is
servername/versionnumber.
For example, the JavaServer Web Development Kit may return the string
JavaServer Web Dev Kit/1.0 .
The servlet container may return other optional information
after the primary string in parentheses, for example,
JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86) .
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public javax.servlet.Servlet | getServlet(java.lang.String name)
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public java.lang.String | getServletContextName()Returns the name of this web application corresponding to this ServletContext as specified in the deployment
descriptor for this web application by the display-name element.
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public java.util.Enumeration | getServletNames()
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public java.util.Enumeration | getServlets()
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public void | log(java.lang.String msg)Writes the specified message to a servlet log file, usually
an event log. The name and type of the servlet log file is
specific to the servlet container.
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public void | log(java.lang.Exception exception, java.lang.String msg)
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public void | log(java.lang.String message, java.lang.Throwable throwable)Writes an explanatory message and a stack trace
for a given Throwable exception
to the servlet log file. The name and type of the servlet log
file is specific to the servlet container, usually an event log.
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public void | removeAttribute(java.lang.String name)Removes the attribute with the given name from
the servlet context. After removal, subsequent calls to
{@link #getAttribute} to retrieve the attribute's value
will return null .
If listeners are configured on the ServletContext the
container notifies them accordingly.
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public void | setAttribute(java.lang.String name, java.lang.Object object)Binds an object to a given attribute name in this servlet context. If
the name specified is already used for an attribute, this
method will replace the attribute with the new to the new attribute.
If listeners are configured on the ServletContext the
container notifies them accordingly.
If a null value is passed, the effect is the same as calling
removeAttribute() .
Attribute names should follow the same convention as package
names. The Java Servlet API specification reserves names
matching java.* , javax.* , and
sun.* .
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