Package org.apache.commons.jelly

Class JellyContext

java.lang.Object
org.apache.commons.jelly.JellyContext
Direct Known Subclasses:
JellyServletContext
public class JellyContext extends Object

JellyContext represents the Jelly context.

Version:
$Revision: 227285 $
Author:
James Strachan

  • Field Details

    • classLoader

      protected ClassLoader classLoader
      The class loader to use for instantiating application objects. If not specified, the context class loader, or the class loader used to load this class itself, is used, based on the value of the useContextClassLoader variable.

    • useContextClassLoader

      protected boolean useContextClassLoader
      Do we want to use the Context ClassLoader when loading classes for instantiating new objects? Default is false.

  • Constructor Details

    • JellyContext

      public JellyContext()
      Create a new context with the currentURL set to the rootURL

    • JellyContext

      public JellyContext(URL rootURL)
      Create a new context with the given rootURL
      Parameters:
      rootURL - the root URL used in resolving absolute resources i.e. those starting with '/'

    • JellyContext

      public JellyContext(URL rootURL, URL currentURL)
      Create a new context with the given rootURL and currentURL
      Parameters:
      rootURL - the root URL used in resolving absolute resources i.e. those starting with '/'
      currentURL - the root URL used in resolving relative resources

    • JellyContext

      public JellyContext(JellyContext parent)
      Create a new context with the given parent context. The parent's rootURL and currentURL are set on the child, and the parent's variables are available in the child context under the name parentScope.
      Parameters:
      parent - the parent context for the newly created context.

    • JellyContext

      public JellyContext(JellyContext parentJellyContext, URL currentURL)
      Create a new context with the given parent context. The parent's rootURL are set on the child, and the parent's variables are available in the child context under the name parentScope.
      Parameters:
      parentJellyContext - the parent context for the newly created context.
      currentURL - the root URL used in resolving relative resources

    • JellyContext

      public JellyContext(JellyContext parentJellyContext, URL rootURL, URL currentURL)
      Create a new context with the given parent context. The parent's variables are available in the child context under the name parentScope.
      Parameters:
      parentJellyContext - the parent context for the newly created context.
      rootURL - the root URL used in resolving absolute resources i.e. those starting with '/'
      currentURL - the root URL used in resolving relative resources

  • Method Details

    • getParent

      public JellyContext getParent()
      Returns:
      the parent context for this context

    • getScope

      public JellyContext getScope(String name)
      Returns:
      the scope of the given name, such as the 'parent' scope. If Jelly is used in a Servlet situation then 'request', 'session' and 'application' are other names for scopes

    • findVariable

      public Object findVariable(String name)
      Finds the variable value of the given name in this context or in any other parent context. If this context does not contain the variable, then its parent is used and then its parent and so forth until the context with no parent is found.
      Returns:
      the value of the variable in this or one of its descendant contexts or null if the variable could not be found.

    • getVariable

      public Object getVariable(String name)
      Returns:
      the value of the given variable name

    • getVariableWithDefaultValue

      public Object getVariableWithDefaultValue(String name, Object defaultValue)
      Gets the value of the variable, or if it's not defined, return the given default value object.

    • getVariable

      public Object getVariable(String name, String scopeName)
      Parameters:
      name - is the name of the variable
      scopeName - is the optional scope name such as 'parent'. For servlet environments this could be 'application', 'session' or 'request'.
      Returns:
      the value of the given variable name in the given variable scope

    • setVariable

      public void setVariable(String name, Object value)
      Sets the value of the named variable

    • setVariable

      public void setVariable(String name, String scopeName, Object value)
      Sets the value of the given variable name in the given variable scope
      Parameters:
      name - is the name of the variable
      scopeName - is the optional scope name such as 'parent'. For servlet environments this could be 'application', 'session' or 'request'.
      value - is the value of the attribute

    • removeVariable

      public void removeVariable(String name)
      Removes the given variable

    • removeVariable

      public void removeVariable(String name, String scopeName)
      Removes the given variable in the specified scope.
      Parameters:
      name - is the name of the variable
      scopeName - is the optional scope name such as 'parent'. For servlet environments this could be 'application', 'session' or 'request'.

    • getVariableNames

      public Iterator getVariableNames()
      Returns:
      an Iterator over the current variable names in this context

    • getVariables

      public Map getVariables()
      Returns:
      the Map of variables in this scope

    • setVariables

      public void setVariables(Map variables)
      Sets the Map of variables to use

    • newJellyContext

      public JellyContext newJellyContext(Map newVariables)
      A factory method to create a new child context of the current context.

    • newJellyContext

      public JellyContext newJellyContext()
      A factory method to create a new child context of the current context.

    • clear

      public void clear()
      Clears variables set by Tags.
      See Also:

    • clearVariables

      protected void clearVariables()
      Clears variables set by Tags (variables set while running a Jelly script)
      See Also:

    • registerTagLibrary

      public void registerTagLibrary(String namespaceURI, TagLibrary taglib)
      Registers the given tag library against the given namespace URI. This should be called before the parser is used.

    • registerTagLibrary

      public void registerTagLibrary(String namespaceURI, String className)
      Registers the given tag library class name against the given namespace URI. The class will be loaded via the given ClassLoader This should be called before the parser is used.

    • isTagLibraryRegistered

      public boolean isTagLibraryRegistered(String namespaceURI)

    • getTagLibrary

      public TagLibrary getTagLibrary(String namespaceURI)
      Returns:
      the TagLibrary for the given namespace URI or null if one could not be found

    • compileScript

      public Script compileScript(String uri) throws JellyException
      Attempts to parse the script from the given uri using the getResource(java.lang.String) method then returns the compiled script.
      Throws:
      JellyException

    • compileScript

      public Script compileScript(URL url) throws JellyException
      Attempts to parse the script from the given URL using the getResource(java.lang.String) method then returns the compiled script.
      Throws:
      JellyException

    • compileScript

      public Script compileScript(InputSource source) throws JellyException
      Attempts to parse the script from the given InputSource using the getResource(java.lang.String) method then returns the compiled script.
      Throws:
      JellyException

    • getXMLParser

      protected XMLParser getXMLParser()
      Returns:
      a thread pooled XMLParser to avoid the startup overhead of the XMLParser

    • createXMLParser

      protected XMLParser createXMLParser()
      Factory method to allow JellyContext implementations to overload how an XMLParser is created - such as to overload what the default ExpressionFactory should be.

    • runScript

      public JellyContext runScript(File file, XMLOutput output) throws JellyException
      Parses the script from the given File then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(URL url, XMLOutput output) throws JellyException
      Parses the script from the given URL then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(InputSource source, XMLOutput output) throws JellyException
      Parses the script from the given InputSource then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(String uri, XMLOutput output) throws JellyException
      Parses the script from the given uri using the JellyContext.getResource() API then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(String uri, XMLOutput output, boolean export, boolean inherit) throws JellyException
      Parses the script from the given uri using the JellyContext.getResource() API then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(File file, XMLOutput output, boolean export, boolean inherit) throws JellyException
      Parses the script from the given file then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(URL url, XMLOutput output, boolean export, boolean inherit) throws JellyException
      Parses the script from the given URL then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • runScript

      public JellyContext runScript(InputSource source, XMLOutput output, boolean export, boolean inherit) throws JellyException
      Parses the script from the given InputSource then compiles it and runs it.
      Returns:
      the new child context that was used to run the script
      Throws:
      JellyException

    • getResource

      public URL getResource(String uri) throws MalformedURLException
      Returns a URL for the given resource from the specified path. If the uri starts with "/" then the path is taken as relative to the current context root. If the uri is a well formed URL then it is used. If the uri is a file that exists and can be read then it is used. Otherwise the uri is interpreted as relative to the current context (the location of the current script).
      Throws:
      MalformedURLException

    • getResourceAsStream

      public InputStream getResourceAsStream(String uri)
      Attempts to open an InputStream to the given resource at the specified path. If the uri starts with "/" then the path is taken as relative to the current context root. If the uri is a well formed URL then it is used. Otherwise the uri is interpreted as relative to the current context (the location of the current script).
      Returns:
      null if this resource could not be loaded, otherwise the resources input stream is returned.

    • getRootURL

      public URL getRootURL()
      Returns:
      the current root context URL from which all absolute resource URIs will be relative to. For example in a web application the root URL will map to the web directory which contains the WEB-INF directory.

    • setRootURL

      public void setRootURL(URL rootURL)
      Sets the current root context URL from which all absolute resource URIs will be relative to. For example in a web application the root URL will map to the web directory which contains the WEB-INF directory.

    • getCurrentURL

      public URL getCurrentURL()
      Returns:
      the current URL context of the current script that is executing. This URL context is used to deduce relative scripts when relative URIs are used in calls to getResource(java.lang.String) to process relative scripts.

    • setCurrentURL

      public void setCurrentURL(URL currentURL)
      Sets the current URL context of the current script that is executing. This URL context is used to deduce relative scripts when relative URIs are used in calls to getResource(java.lang.String) to process relative scripts.

    • isCacheTags

      public boolean isCacheTags()
      Returns whether caching of Tag instances, per thread, is enabled. Caching Tags can boost performance, on some JVMs, by reducing the cost of object construction when running Jelly inside a multi-threaded application server such as a Servlet engine.
      Returns:
      whether caching of Tag instances is enabled.

    • setCacheTags

      public void setCacheTags(boolean cacheTags)
      Sets whether caching of Tag instances, per thread, is enabled. Caching Tags can boost performance, on some JVMs, by reducing the cost of object construction when running Jelly inside a multi-threaded application server such as a Servlet engine.
      Parameters:
      cacheTags - Whether caching should be enabled or disabled.

    • isExportLibraries

      public boolean isExportLibraries()
      Returns whether we export tag libraries to our parents context
      Returns:
      boolean

    • setExportLibraries

      public void setExportLibraries(boolean exportLibraries)
      Sets whether we export tag libraries to our parents context
      Parameters:
      exportLibraries - The exportLibraries to set

    • setExport

      public void setExport(boolean export)
      Sets whether we should export variable definitions to our parent context

    • isExport

      public boolean isExport()
      Returns:
      whether we should export variable definitions to our parent context

    • setInherit

      public void setInherit(boolean inherit)
      Sets whether we should inherit variables from our parent context

    • isInherit

      public boolean isInherit()
      Returns:
      whether we should inherit variables from our parent context

    • setAllowDtdToCallExternalEntities

      public void setAllowDtdToCallExternalEntities(boolean allowDtdToCallExternalEntities)
      Sets whether we should allow our doctype definitions to call out to external entities.

    • isAllowDtdToCallExternalEntities

      public boolean isAllowDtdToCallExternalEntities()
      Returns:
      whether we should allow our doctype definitions to call out to external entities.

    • getClassLoader

      public ClassLoader getClassLoader()
      Return the class loader to be used for instantiating application objects when required. This is determined based upon the following rules:
      • The class loader set by setClassLoader(), if any
      • The thread context class loader, if it exists and the useContextClassLoader property is set to true
      • The class loader used to load the XMLParser class itself.

    • setClassLoader

      public void setClassLoader(ClassLoader classLoader)
      Set the class loader to be used for instantiating application objects when required.
      Parameters:
      classLoader - The new class loader to use, or null to revert to the standard rules

    • getUseContextClassLoader

      public boolean getUseContextClassLoader()
      Return the boolean as to whether the context classloader should be used.

    • setUseContextClassLoader

      public void setUseContextClassLoader(boolean use)
      Determine whether to use the Context ClassLoader (the one found by calling Thread.currentThread().getContextClassLoader()) to resolve/load classes. If not using Context ClassLoader, then the class-loading defaults to using the calling-class' ClassLoader.
      Parameters:
      use - determines whether to use JellyContext ClassLoader.

    • createRelativeURL

      protected URL createRelativeURL(URL rootURL, String relativeURI) throws MalformedURLException
      Parameters:
      rootURL - is the root context from which the relative URI will be applied
      relativeURI - is the relative URI (without a leading "/")
      Returns:
      a new relative URL from the given root and with the addition of the extra relative URI
      Throws:
      MalformedURLException - if the URL is invalid.

    • getJellyContextURL

      protected URL getJellyContextURL(URL url) throws MalformedURLException
      Strips off the name of a script to create a new context URL
      Throws:
      MalformedURLException

    • getJellyContextURL

      protected URL getJellyContextURL(InputSource source) throws MalformedURLException
      Strips off the name of a script to create a new context URL
      Throws:
      MalformedURLException

    • createChildContext

      protected JellyContext createChildContext()
      Factory method to create a new child of this context

    • setParent

      protected void setParent(JellyContext context)
      Change the parent context to the one provided
      Parameters:
      context - the new parent context