org.apache.velocity.tools.view.servlet
Class ServletToolboxManager

java.lang.Object
  |
  +--org.apache.velocity.tools.view.XMLToolboxManager
        |
        +--org.apache.velocity.tools.view.servlet.ServletToolboxManager

All Implemented Interfaces:

ToolboxManager

public class ServletToolboxManager

extends XMLToolboxManager

A toolbox manager for the servlet environment.

A toolbox manager is responsible for automatically filling the Velocity context with a set of view tools. This class provides the following features:

• configurable through an XML-based configuration file
• assembles a set of view tools (the toolbox) on request
• handles different tool scopes (request, session, application)
• supports any class with a public constructor without parameters to be used as a view tool
• supports adding primitive data values to the context(String,Number,Boolean)

Configuration

The toolbox manager is configured through an XML-based configuration file. The configuration file is passed to the XMLToolboxManager.load(java.io.InputStream input) method. The required format is shown in the following example:

 
 <?xml version="1.0"?>
 
 <toolbox>
   <tool>
      <key>toolLoader</key>
      <scope>application</scope>
      <class>org.apache.velocity.tools.tools.ToolLoader</class>
   </tool>
   <tool>
      <key>math</key>
      <scope>application</scope>
      <class>org.apache.velocity.tools.tools.MathTool</class>
   </tool>
   <data type="number">
      <key>luckynumber</key>
      <value>1.37</class>
   </data>
   <data type="string">
      <key>greeting</key>
      <value>Hello World!</class>
   </data>
 </toolbox>    
 

The recommended location for the configuration file is the WEB-INF directory of the web application.

Version:

$Id: ServletToolboxManager.java,v 1.4 2003/05/28 00:17:16 nbubna Exp $

Author:

Gabriel Sidler, Nathan Bubna, Geir Magnusson Jr.

Field Summary

private java.util.Map	appTools
private boolean	createSession
static java.lang.String	ELEMENT_CREATE_SESSION
static java.lang.String	ELEMENT_SCOPE
private static java.util.HashMap	managersMap
private java.util.ArrayList	requestToolInfo
private javax.servlet.ServletContext	servletContext
static java.lang.String	SESSION_TOOLS_KEY
private java.util.ArrayList	sessionToolInfo
static java.lang.String	VALUE_NO
static java.lang.String	VALUE_YES

Fields inherited from class org.apache.velocity.tools.view.XMLToolboxManager

ATTRIBUTE_TYPE, BASE_NODE, ELEMENT_CLASS, ELEMENT_DATA, ELEMENT_KEY, ELEMENT_TOOL, ELEMENT_VALUE

Constructor Summary

private

ServletToolboxManager(javax.servlet.ServletContext servletContext) Use getInstance(ServletContext,String) instead to ensure there is exactly one ServletToolboxManager per xml toolbox configuration file.

Method Summary

void	addTool(ToolInfo info) Overrides XMLToolboxManager to separate tools by scope.
static ServletToolboxManager	getInstance(javax.servlet.ServletContext servletContext, java.lang.String toolboxFile) ServletToolboxManager factory method.
ToolboxContext	getToolboxContext(java.lang.Object initData) Overrides XMLToolboxManager to handle the separate scopes.
protected void	log(java.lang.String s) Overrides XMLToolboxManager
protected boolean	readCreateSession(org.dom4j.Element e) Reads the value for create-session.
protected boolean	readElement(org.dom4j.Element e) Overrides XMLToolboxManager to handle the create-session element.
protected ToolInfo	readToolInfo(org.dom4j.Element e) Overrides XMLToolboxManager to read a ServletToolInfo instead of a ViewToolInfo.
void	setCreateSession(boolean b) Sets whether or not to create a new session when none exists for the current request and session-scoped tools have been defined for this toolbox.

Methods inherited from class org.apache.velocity.tools.view.XMLToolboxManager

load, readDataInfo

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ELEMENT_SCOPE

public static final java.lang.String ELEMENT_SCOPE

See Also:

Constant Field Values

ELEMENT_CREATE_SESSION

public static final java.lang.String ELEMENT_CREATE_SESSION

See Also:

Constant Field Values

VALUE_YES

public static final java.lang.String VALUE_YES

See Also:

Constant Field Values

VALUE_NO

public static final java.lang.String VALUE_NO

See Also:

Constant Field Values

SESSION_TOOLS_KEY

public static final java.lang.String SESSION_TOOLS_KEY

See Also:

Constant Field Values

servletContext

private javax.servlet.ServletContext servletContext

appTools

private java.util.Map appTools

sessionToolInfo

private java.util.ArrayList sessionToolInfo

requestToolInfo

private java.util.ArrayList requestToolInfo

createSession

private boolean createSession

managersMap

private static java.util.HashMap managersMap

Constructor Detail

ServletToolboxManager

private ServletToolboxManager(javax.servlet.ServletContext servletContext)

Use getInstance(ServletContext,String) instead to ensure there is exactly one ServletToolboxManager per xml toolbox configuration file.

Method Detail

getInstance

public static ServletToolboxManager getInstance(javax.servlet.ServletContext servletContext,
                                                java.lang.String toolboxFile)

ServletToolboxManager factory method. This method will ensure there is exactly one ServletToolboxManager per xml toolbox configuration file.

setCreateSession

public void setCreateSession(boolean b)

Sets whether or not to create a new session when none exists for the current request and session-scoped tools have been defined for this toolbox.

If true, then a call to getToolboxContext(Object) will create a new session if none currently exists for this request and the toolbox has one or more session-scoped tools designed.

If false, then a call to getToolboxContext(Object) will never create a new session for the current request. This effectively means that no session-scoped tools will be added to the ToolboxContext for a request that does not have a session object.

The default value is true.

log

protected void log(java.lang.String s)

Overrides XMLToolboxManager

Overrides:

log in class XMLToolboxManager

readElement

protected boolean readElement(org.dom4j.Element e)
                       throws java.lang.Exception

Overrides XMLToolboxManager to handle the create-session element.

Overrides:

readElement in class XMLToolboxManager

java.lang.Exception

readCreateSession

protected boolean readCreateSession(org.dom4j.Element e)
                             throws java.lang.Exception

Reads the value for create-session.

java.lang.Exception

See Also:

setCreateSession(boolean)

readToolInfo

protected ToolInfo readToolInfo(org.dom4j.Element e)
                         throws java.lang.Exception

Overrides XMLToolboxManager to read a ServletToolInfo instead of a ViewToolInfo.

Overrides:

readToolInfo in class XMLToolboxManager

java.lang.Exception

addTool

public void addTool(ToolInfo info)

Overrides XMLToolboxManager to separate tools by scope. For this to work, we obviously override getToolboxContext(Object) as well.

Specified by:

addTool in interface ToolboxManager

Overrides:

addTool in class XMLToolboxManager

getToolboxContext

public ToolboxContext getToolboxContext(java.lang.Object initData)

Overrides XMLToolboxManager to handle the separate scopes. Application scope tools were initialized when the toolbox was loaded. Session scope tools are initialized once per session and stored in a map in the session attributes. Request scope tools are initialized on every request.

Specified by:

getToolboxContext in interface ToolboxManager

Overrides:

getToolboxContext in class XMLToolboxManager

Parameters:

initData - the ViewContext for the current servlet request

Returns:

the created ToolboxContext