PortletContext (JSR 362 Portlet 3.0 API Specification)

All Known Implementing Classes:

PortletContextWrapper
```
public interface PortletContext
```
The PortletContext interface defines a portlet view of the portlet container. The PortletContext also makes resources available to the portlet. Using the context, a portlet can access the portlet log, and obtain URL references to resources.
There is one context per "portlet application" per Java Virtual Machine. (A "portlet application" is a collection of portlets, servlets, and content installed under a specific subset of the server URL namespace, such as /catalog. They are possibly installed via a .war file.) As a web application, a portlet application also has a servlet context. The portlet context leverages most of its functionality from the servlet context of the portlet application.
Attributes stored in the context are global for all users and all components in the portlet application.
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 cannot be used as a location to share global information (because the information is not truly global). Use an external resource, such as a database to achieve sharing on a global scope.

Method Summary

Methods
Modifier and Type	Method and Description
`Object`	`getAttribute(String name)` Returns the portlet container attribute with the given name, or null if there is no attribute by that name.
`Enumeration<String>`	`getAttributeNames()` Returns an `Enumeration` containing the attribute names available within this portlet context, or an empty `Enumeration` if no attributes are available.
`ClassLoader`	`getClassLoader()` Returns the class loader for this portlet context.
`Enumeration<String>`	`getContainerRuntimeOptions()` Returns the container container runtime options keys supported by this portlet container.
`String`	`getContextPath()` Returns the context path for this portlet application.
`int`	`getEffectiveMajorVersion()` Returns the major version of the Portlet API used by the portlet application running in this PortletContext.
`int`	`getEffectiveMinorVersion()` Returns the minor version of the Portlet API used by the portlet application running in this PortletContext.
`String`	`getInitParameter(String name)` Returns a String containing the value of the named context-wide initialization parameter, or `null` if the parameter does not exist.
`Enumeration<String>`	`getInitParameterNames()` Returns the names of the context initialization parameters as an `Enumeration` of String objects, or an empty Enumeration if the context has no initialization parameters.
`int`	`getMajorVersion()` Returns the major version of the Portlet API that this portlet container supports.
`String`	`getMimeType(String file)` Returns the MIME type of the specified file, or `null` if the MIME type is not known.
`int`	`getMinorVersion()` Returns the minor version of the Portlet API that this portlet container supports.
`PortletRequestDispatcher`	`getNamedDispatcher(String name)` Returns a `PortletRequestDispatcher` object that acts as a wrapper for the named servlet.
`String`	`getPortletContextName()` Returns the name of this portlet application correponding to this PortletContext as specified in the `web.xml` deployment descriptor for this web application by the `display-name` element.
`String`	`getRealPath(String path)` Returns a `String` containing the real path for a given virtual path.
`PortletRequestDispatcher`	`getRequestDispatcher(String path)` Returns a `PortletRequestDispatcher` object that acts as a wrapper for the resource located at the given path.
`URL`	`getResource(String path)` Returns a URL to the resource that is mapped to a specified path.
`InputStream`	`getResourceAsStream(String path)` Returns the resource located at the given path as an InputStream object.
`Set<String>`	`getResourcePaths(String path)` Returns a directory-like listing of all the paths to resources within the web application longest sub-path of which matches the supplied path argument.
`String`	`getServerInfo()` Returns the name and version of the portlet container in which the portlet is running.
`void`	`log(String msg)` Writes the specified message to a portlet log file, usually an event log.
`void`	`log(String message, Throwable throwable)` Writes an explanatory message and a stack trace for a given Throwable exception to the portlet log file.
`void`	`removeAttribute(String name)` Removes the attribute with the given name from the portlet context.
`void`	`setAttribute(String name, Object object)` Binds an object to a given attribute name in this portlet context.

- Method Detail
  - getServerInfo
```
String getServerInfo()
```
    Returns the name and version of the portlet container in which the portlet is running.
    The form of the returned string is containername/versionnumber.
    
    Returns:
    the string containing at least name and version number
  - getRequestDispatcher
```
PortletRequestDispatcher getRequestDispatcher(String path)
```
    Returns a PortletRequestDispatcher object that acts as a wrapper for the resource located at the given path. A PortletRequestDispatcher object can be used include the resource in a response. The resource can be dynamic or static.
    The pathname must begin with a slash ( / ) and is interpreted as relative to the current context root.
    This method returns null if the PortletContext cannot return a PortletRequestDispatcher for any reason.
    
    Parameters:
    path - a String specifying the pathname to the resource
    
    Returns:
    a PortletRequestDispatcher object that acts as a wrapper for the resource at the specified path.
    See Also:
    PortletRequestDispatcher
  - getNamedDispatcher
```
PortletRequestDispatcher getNamedDispatcher(String name)
```
    Returns a PortletRequestDispatcher object that acts as a wrapper for the named servlet.
    Servlets (and also JSP pages) may be given names via server administration or via a web application deployment descriptor.
    This method returns null if the PortletContext cannot return a PortletRequestDispatcher for any reason.
    
    Parameters:
    name - a String specifying the name of a servlet to be wrapped
    
    Returns:
    a PortletRequestDispatcher object that acts as a wrapper for the named servlet
    See Also:
    PortletRequestDispatcher
  - getResourceAsStream
```
InputStream getResourceAsStream(String path)
```
    Returns the resource located at the given path as an InputStream object. The data in the InputStream can be of any type or length. The method returns null if no resource exists at the given path.
    In order to access protected resources the path has to be prefixed with /WEB-INF/ (for example /WEB-INF/myportlet/myportlet.jsp). Otherwise, the direct path is used (for example /myportlet/myportlet.jsp).
    
    Parameters:
    path - the path to the resource
    
    Returns:
    the input stream
  - getMajorVersion
```
int getMajorVersion()
```
    Returns the major version of the Portlet API that this portlet container supports.
    
    Returns:
    the major version
    See Also:
    getMinorVersion()
  - getMinorVersion
```
int getMinorVersion()
```
    Returns the minor version of the Portlet API that this portlet container supports.
    
    Returns:
    the minor version
    See Also:
    getMajorVersion()
  - getMimeType
```
String getMimeType(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 portlet container and may be specified in a web application deployment descriptor. Common MIME types are text/html and image/gif.
    
    Parameters:
    file - a String specifying the name of a file
    
    Returns:
    a String specifying the MIME type of the file
  - getRealPath
```
String getRealPath(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 of the portlet container file system.
    The real path returned will be in a form appropriate to the computer and operating system on which the portlet container is running, including the proper path separators. This method returns null if the portlet 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).
    
    Parameters:
    path - a String specifying a virtual path
    
    Returns:
    a String specifying the real path, or null if the transformation cannot be performed.
  - getResourcePaths
```
Set<String> getResourcePaths(String path)
```
    Returns a directory-like listing of all the paths to resources within the web application longest sub-path of which matches the supplied path argument. Paths indicating subdirectory paths end with a slash (/). The returned paths are all relative to the root of the web application and have a leading slash. 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.OrderPortlet.class, getResourcePaths("/") returns {"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"}
    getResourcePaths("/catalog/") returns {"/catalog/index.html", "/catalog/products.html", "/catalog/offers/"}.
    
    Parameters:
    path - the partial path used to match the resources, which must start with a slash
    
    Returns:
    a Set containing the directory listing, or null if there are no resources in the web application of which the path begins with the supplied path.
  - getResource
```
URL getResource(String path)
                throws MalformedURLException
```
    Returns a URL to the resource that is mapped to a specified path. The path must begin with a slash (/) and is interpreted as relative to the current context root.
    This method allows the portlet container to make a resource available to portlets from any source. Resources can be located on a local or remote file system, in a database, or in a .war file.
    The portlet 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.
    
    Parameters:
    path - a String specifying the path to the resource
    
    Returns:
    the resource located at the named path, or null if there is no resource at that path
    
    Throws:
    
    MalformedURLException - if the pathname is not given in the correct form
  - getAttribute
```
Object getAttribute(String name)
```
    Returns the portlet container attribute with the given name, or null if there is no attribute by that name. An attribute allows a portlet container to give the portlet additional information not already provided by this interface. 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 Portlet API specification reserves names matching java.*, javax.*, and sun.*.
    
    Parameters:
    name - a String specifying the name of the attribute
    
    Returns:
    an Object containing the value of the attribute, or null if no attribute exists matching the given name
    
    Throws:
    
    IllegalArgumentException - if name is null.
    See Also:
    getAttributeNames()
  - getAttributeNames
```
Enumeration<String> getAttributeNames()
```
    Returns an Enumeration containing the attribute names available within this portlet context, or an empty Enumeration if no attributes are available. Use the getAttribute(java.lang.String) method with an attribute name to get the value of an attribute.
    
    Returns:
    an Enumeration of attribute names
    See Also:
    getAttribute(java.lang.String)
  - getInitParameter
```
String getInitParameter(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 provides configuration information which may be useful for an entire "portlet application".
    
    Parameters:
    name - a String containing the name of the requested parameter
    
    Returns:
    a String containing the value of the initialization parameter, or null if the parameter does not exist.
    
    Throws:
    
    IllegalArgumentException - if name is null.
    See Also:
    getInitParameterNames()
  - getInitParameterNames
```
Enumeration<String> getInitParameterNames()
```
    Returns the names of the context initialization parameters as an Enumeration of String objects, or an empty Enumeration if the context has no initialization parameters.
    
    Returns:
    an Enumeration of String objects containing the names of the context initialization parameters
    See Also:
    getInitParameter(java.lang.String)
  - log
```
void log(String msg)
```
    Writes the specified message to a portlet log file, usually an event log. The name and type of the portlet log file is specific to the portlet container.
    This method mapps to the ServletContext.log method. The portlet container may in addition log this message in a portlet container specific log file.
    
    Parameters:
    msg - a String specifying the message to be written to the log file
  - log
```
void log(String message,
       Throwable throwable)
```
    Writes an explanatory message and a stack trace for a given Throwable exception to the portlet log file. The name and type of the portlet log file is specific to the portlet container, usually an event log.
    This method is mapped to the ServletContext.log method. The portlet container may in addition log this message in a portlet container specific log file.
    
    Parameters:
    message - a String that describes the error or exception
    throwable - the Throwable error or exception
  - removeAttribute
```
void removeAttribute(String name)
```
    Removes the attribute with the given name from the portlet context. After removal, subsequent calls to getAttribute(java.lang.String) to retrieve the attribute's value will return null.
    
    Parameters:
    name - a String specifying the name of the attribute to be removed
    
    Throws:
    
    IllegalArgumentException - if name is null.
  - setAttribute
```
void setAttribute(String name,
                Object object)
```
    Binds an object to a given attribute name in this portlet context. If the name specified is already used for an attribute, this method removes the old attribute and binds the name to the new attribute.
    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 Portlet API specification reserves names matching java.*, javax.*, and sun.*.
    
    Parameters:
    name - a String specifying the name of the attribute
    object - an Object representing the attribute to be bound
    
    Throws:
    
    IllegalArgumentException - if name is null.
  - getPortletContextName
```
String getPortletContextName()
```
    Returns the name of this portlet application correponding to this PortletContext as specified in the web.xml deployment descriptor for this web application by the display-name element.
    
    Returns:
    The name of the web application or null if no name has been declared in the deployment descriptor.
  - getContainerRuntimeOptions
```
Enumeration<String> getContainerRuntimeOptions()
```
    Returns the container container runtime options keys supported by this portlet container.
    
    Returns:
    container runtime options keys supported by this container as String values.
    Since:
    
    2.0
  - getEffectiveMajorVersion
```
int getEffectiveMajorVersion()
```
    Returns the major version of the Portlet API used by the portlet application running in this PortletContext.
    
    Returns:
    the major version
    Since:
    
    3.0
    
    See Also:
    getEffectiveMinorVersion()
  - getEffectiveMinorVersion
```
int getEffectiveMinorVersion()
```
    Returns the minor version of the Portlet API used by the portlet application running in this PortletContext.
    
    Returns:
    the minor version
    Since:
    
    3.0
    
    See Also:
    getEffectiveMajorVersion()
  - getContextPath
```
String getContextPath()
```
    Returns the context path for this portlet application.
    
    Returns:
    the context path for this portlet application.
    Since:
    
    3.0
  - getClassLoader
```
ClassLoader getClassLoader()
```
    Returns the class loader for this portlet context.
    
    Returns:
    the class loader for this portlet application.
    
    Throws:
    
    SecurityException - - if a security manager denies access to the requested class loader
    Since:
    
    3.0

Java Portlet 3.0 API Specification. See the Copyright and License provided with this distribution. Use is subject to license terms.

Interface PortletContext

Method Summary

Method Detail

getServerInfo

getRequestDispatcher

getNamedDispatcher

getResourceAsStream

getMajorVersion

getMinorVersion

getMimeType

getRealPath

getResourcePaths

getResource

getAttribute

getAttributeNames

getInitParameter

getInitParameterNames

log

log

removeAttribute

setAttribute

getPortletContextName

getContainerRuntimeOptions

getEffectiveMajorVersion

getEffectiveMinorVersion

getContextPath

getClassLoader