AbstractWebConsolePlugin (Apache Felix Web Management Console 3.0.0 API)

java.lang.Object
- javax.servlet.GenericServlet
- - javax.servlet.http.HttpServlet
  - - org.apache.felix.webconsole.AbstractWebConsolePlugin

All Implemented Interfaces:

Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

SimpleWebConsolePlugin
```
public abstract class AbstractWebConsolePlugin
extends javax.servlet.http.HttpServlet
```
The Web Console can be extended by registering an OSGi service for the interface Servlet with the service property felix.webconsole.label set to the label (last segment in the URL) of the page. The respective service is called a Web Console Plugin or a plugin for short. To help rendering the response the Apache Felix Web Console bundle provides two options. One of the options is to extend the AbstractWebConsolePlugin overwriting the renderContent(HttpServletRequest, HttpServletResponse) method.

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`ATTR_FILEUPLOAD` The name of the request attribute containing the map of FileItems from the POST request
`static String`	`GET_RESOURCE_METHOD_NAME` Web Console Plugin typically consists of servlet and resources such as images, scripts or style sheets.

Constructor Summary

Constructors
Constructor and Description

AbstractWebConsolePlugin()

Constructors
Constructor and Description
`AbstractWebConsolePlugin()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`activate(org.osgi.framework.BundleContext bundleContext)` This method is called from the Felix Web Console to ensure the AbstractWebConsolePlugin is correctly setup.
`void`	`deactivate()` This method is called, by the Web Console to de-activate the plugin and release all used resources.
`protected void`	`doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)` Renders the web console page for the request.
`protected void`	`endResponse(PrintWriter pw)` This method is responsible for generating the footer of the page.
`static BrandingPlugin`	`getBrandingPlugin()` Returns the `BrandingPlugin` currently used for web console branding.
`org.osgi.framework.Bundle`	`getBundle()` Returns the `Bundle` pertaining to the `bundle context` with which this plugin has been activated.
`protected org.osgi.framework.BundleContext`	`getBundleContext()` Returns the `BundleContext` with which this plugin has been activated.
`protected String[]`	`getCssReferences()` Returns a list of CSS reference paths or `null` if no additional CSS files are provided by the plugin.
`abstract String`	`getLabel()` Retrieves the label.
`static String`	`getParameter(javax.servlet.http.HttpServletRequest request, String name)` Deprecated. use `WebConsoleUtil.getParameter(HttpServletRequest, String)`
`protected Object`	`getResourceProvider()` Returns the object which might provide resources.
`String`	`getServletName()` Returns the title for this plugin as returned by `getTitle()`
`abstract String`	`getTitle()` Retrieves the title of the plug-in.
`protected boolean`	`isHtmlRequest(javax.servlet.http.HttpServletRequest request)` Detects whether this request is intended to have the headers and footers of this plugin be rendered or not.
`void`	`log(int level, String message)` Calls the `GenericServlet.log(String)` method if the configured log level is less than or equal to the given `level`.
`void`	`log(int level, String message, Throwable t)` Calls the `GenericServlet.log(String, Throwable)` method if the configured log level is less than or equal to the given `level`.
`protected String`	`readTemplateFile(String templateFile)` Reads the `templateFile` as a resource through the class loader of this class converting the binary data into a string using UTF-8 encoding.
`protected abstract void`	`renderContent(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res)` This method is used to render the content of the plug-in.
`protected void`	`renderTopNavigation(javax.servlet.http.HttpServletRequest request, PrintWriter pw)` This method is called to generate the top level links with the available plug-ins.
`protected void`	`sendRedirect(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, String redirectUrl)` Deprecated. use `WebConsoleUtil.sendRedirect(HttpServletRequest, HttpServletResponse, String)`
`static void`	`setBrandingPlugin(BrandingPlugin brandingPlugin)` Sets the `BrandingPlugin` to use globally by all extensions of this class for branding.
`static void`	`setLogLevel(int logLevel)` Sets the log level to be applied for calls to the `log(int, String)` and `log(int, String, Throwable)` methods.
`protected PrintWriter`	`startResponse(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)` This method is responsible for generating the top heading of the page.

Methods inherited from class javax.servlet.http.HttpServlet
doDelete, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet
destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, init, init, log, log

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ATTR_FILEUPLOAD
```
public static final String ATTR_FILEUPLOAD
```
    The name of the request attribute containing the map of FileItems from the POST request
    
    See Also:
    Constant Field Values
  - GET_RESOURCE_METHOD_NAME
```
public static final String GET_RESOURCE_METHOD_NAME
```
    Web Console Plugin typically consists of servlet and resources such as images, scripts or style sheets. To load resources, a Resource Provider is used. The resource provider is an object, that provides a method which name is specified by this constants and it is 'getResource'.
    
    See Also:
    getResourceProvider(), Constant Field Values
- Constructor Detail
  - AbstractWebConsolePlugin
```
public AbstractWebConsolePlugin()
```
- Method Detail
  - getServletName
```
public String getServletName()
```
    Returns the title for this plugin as returned by getTitle()
    
    Specified by:
    
    getServletName in interface javax.servlet.ServletConfig
    
    Overrides:
    
    getServletName in class javax.servlet.GenericServlet
    
    See Also:
    GenericServlet.getServletName()
  - doGet
```
protected void doGet(javax.servlet.http.HttpServletRequest request,
         javax.servlet.http.HttpServletResponse response)
              throws javax.servlet.ServletException,
                     IOException
```
    Renders the web console page for the request. This consist of the following five parts called in order:
    1. Send back a requested resource
    2. startResponse(HttpServletRequest, HttpServletResponse)
    3. renderTopNavigation(HttpServletRequest, PrintWriter)
    4. renderContent(HttpServletRequest, HttpServletResponse)
    5. endResponse(PrintWriter)
    Note: If a resource is sent back for the request only the first step is executed. Otherwise the first step is a null-operation actually and the latter four steps are executed in order.
    Overrides:
    
    doGet in class javax.servlet.http.HttpServlet
    
    Throws:
    
    javax.servlet.ServletException
    
    IOException
    See Also:
    HttpServlet.doGet( javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
  - isHtmlRequest
```
protected boolean isHtmlRequest(javax.servlet.http.HttpServletRequest request)
```
    Detects whether this request is intended to have the headers and footers of this plugin be rendered or not. This method always returns true but has been overwritten in the WebConsolePluginAdapter for the plugins.
    Parameters: request - the original request passed from the HTTP server Returns: true if the page should have headers and footers rendered
  activate public void activate(org.osgi.framework.BundleContext bundleContext) This method is called from the Felix Web Console to ensure the AbstractWebConsolePlugin is correctly setup. It is called right after the Web Console receives notification for plugin registration. Parameters: bundleContext - the context of the plugin bundle deactivate public void deactivate() This method is called, by the Web Console to de-activate the plugin and release all used resources. renderContent protected abstract void renderContent(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse res) throws javax.servlet.ServletException, IOException This method is used to render the content of the plug-in. It is called internally from the Web Console. Parameters: req - the HTTP request send from the user res - the HTTP response object, where to render the plugin data. Throws: IOException - if an input or output error is detected when the servlet handles the request javax.servlet.ServletException - if the request for the GET could not be handled getLabel public abstract String getLabel() Retrieves the label. This is the last component in the servlet path. This method MUST be overridden, if the AbstractWebConsolePlugin() constructor is used. Returns: the label. getTitle public abstract String getTitle() Retrieves the title of the plug-in. It is displayed in the page header and is also included in the title of the HTML document. This method MUST be overridden, if the AbstractWebConsolePlugin() constructor is used. Returns: the plugin title. getCssReferences protected String[] getCssReferences() Returns a list of CSS reference paths or null if no additional CSS files are provided by the plugin. The result is an array of strings which are used as the value of the href attribute of the <link> elements placed in the head section of the HTML generated. If the reference is a relative path, it is turned into an absolute path by prepending the value of the WebConsoleConstants.ATTR_APP_ROOT request attribute. Returns: The list of additional CSS files to reference in the head section or null if no such CSS files are required. getBundleContext protected org.osgi.framework.BundleContext getBundleContext() Returns the BundleContext with which this plugin has been activated. If the plugin has not be activated by calling the activate(BundleContext) method, this method returns null. Returns: the bundle context or null if the bundle is not activated. getBundle public final org.osgi.framework.Bundle getBundle() Returns the Bundle pertaining to the bundle context with which this plugin has been activated. If the plugin has not be activated by calling the activate(BundleContext) method, this method returns null. Returns: the bundle or null if the plugin is not activated. getResourceProvider protected Object getResourceProvider() Returns the object which might provide resources. The class of this object is used to find the getResource method. This method may be overwritten by extensions. This base class implementation returns this instance. Returns: The resource provider object or null if no resources will be provided by this plugin. log public void log(int level, String message) Calls the GenericServlet.log(String) method if the configured log level is less than or equal to the given level. Note, that the level paramter is only used to decide whether the GenericServlet.log(String) method is called or not. The actual implementation of the GenericServlet.log method is outside of the control of this method. Parameters: level - The log level at which to log the message message - The message to log log public void log(int level, String message, Throwable t) Calls the GenericServlet.log(String, Throwable) method if the configured log level is less than or equal to the given level. Note, that the level paramter is only used to decide whether the GenericServlet.log(String, Throwable) method is called or not. The actual implementation of the GenericServlet.log method is outside of the control of this method. Parameters: level - The log level at which to log the message message - The message to log t - The Throwable to log with the message startResponse protected PrintWriter startResponse(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws IOException This method is responsible for generating the top heading of the page. Parameters: request - the HTTP request coming from the user response - the HTTP response, where data is rendered Returns: the writer that was used for generating the response. Throws: IOException - on I/O error See Also: endResponse(PrintWriter) renderTopNavigation protected void renderTopNavigation(javax.servlet.http.HttpServletRequest request, PrintWriter pw) This method is called to generate the top level links with the available plug-ins. Parameters: request - the HTTP request coming from the user pw - the writer, where the HTML data is rendered endResponse protected void endResponse(PrintWriter pw) This method is responsible for generating the footer of the page. Parameters: pw - the writer, where the HTML data is rendered See Also: startResponse(HttpServletRequest, HttpServletResponse) getParameter public static final String getParameter(javax.servlet.http.HttpServletRequest request, String name) Deprecated. use WebConsoleUtil.getParameter(HttpServletRequest, String) An utility method, that is used to filter out simple parameter from file parameter when multipart transfer encoding is used. This method processes the request and sets a request attribute ATTR_FILEUPLOAD. The attribute value is a Map where the key is a String specifying the field name and the value is a FileItem. Parameters: request - the HTTP request coming from the user name - the name of the parameter Returns: if not multipart transfer encoding is used - the value is the parameter value or null if not set. If multipart is used, and the specified parameter is field - then the value of the parameter is returned. sendRedirect protected void sendRedirect(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, String redirectUrl) throws IOException Deprecated. use WebConsoleUtil.sendRedirect(HttpServletRequest, HttpServletResponse, String) Utility method to handle relative redirects. Some application servers like Web Sphere handle relative redirects differently therefore we should make an absolute URL before invoking send redirect. Parameters: request - the HTTP request coming from the user response - the HTTP response, where data is rendered redirectUrl - the redirect URI. Throws: IOException - If an input or output exception occurs IllegalStateException - If the response was committed or if a partial URL is given and cannot be converted into a valid URL getBrandingPlugin public static BrandingPlugin getBrandingPlugin() Returns the BrandingPlugin currently used for web console branding. Returns: the brandingPlugin setBrandingPlugin public static final void setBrandingPlugin(BrandingPlugin brandingPlugin) Sets the BrandingPlugin to use globally by all extensions of this class for branding. Note: This method is intended to be used internally by the Web Console to update the branding plugin to use. Parameters: brandingPlugin - the brandingPlugin to set setLogLevel public static final void setLogLevel(int logLevel) Sets the log level to be applied for calls to the log(int, String) and log(int, String, Throwable) methods. Note: This method is intended to be used internally by the Web Console to update the log level according to the Web Console configuration. Parameters: logLevel - readTemplateFile protected final String readTemplateFile(String templateFile) Reads the templateFile as a resource through the class loader of this class converting the binary data into a string using UTF-8 encoding. If the template file cannot read into a string and an exception is caused, the exception is logged and an empty string returned. Parameters: templateFile - The absolute path to the template file to read. Returns: The contents of the template file as a string or and empty string if the template file fails to be read. Throws: NullPointerException - if templateFile is null RuntimeException - if an IOException is thrown reading the template file into a string. The exception provides the exception thrown as its cause.

Class AbstractWebConsolePlugin

Field Summary

Constructor Summary

Method Summary

Methods inherited from class javax.servlet.http.HttpServlet

Methods inherited from class javax.servlet.GenericServlet

Methods inherited from class java.lang.Object

Field Detail

ATTR_FILEUPLOAD

GET_RESOURCE_METHOD_NAME

Constructor Detail

AbstractWebConsolePlugin

Method Detail

getServletName

doGet

isHtmlRequest

activate

deactivate

renderContent

getLabel

getTitle

getCssReferences

getBundleContext

getBundle

getResourceProvider

log

log

startResponse

renderTopNavigation

endResponse

getParameter

sendRedirect

getBrandingPlugin

setBrandingPlugin

setLogLevel

readTemplateFile