org.mmbase.applications.dove
Class AbstractDove

java.lang.Object
  org.mmbase.applications.dove.AbstractDove

Direct Known Subclasses:

Dove

public abstract class AbstractDove
extends Object

This class handles Remote Procedure Calls described using a DOM model. The original data is received in xml, likely through a specialized servlet such as the DoveServlet (but this is not required. it may, for instance, be possible to use this class in conjunction with SOAP or even outside a servlet context). The call should result in a new DOM tree (see the EditWizard API for details).
XXX: Currently, this class performs some type of validation on the xml received. If errors occur, they are included in the response, at the place where they occur. This means that the <error > tag can occur anywhere in the response, which is not very neat.
Errors have three types:
parser : the xml given is invalid or does not follow the grammar. This likely means there is a bug in the client code.
server : the code invoked is either not yet implemented or another, server-related, error occurred (such as no memory, bad configuration, etc.). Server errors entirely fail a request.
client : The data requested could not be retrieved or values specified were invalid. I.e. a requested node does not exist (any more), or a put failed due to locking or invalid data.

This is ONLY for debugging purposes! XML validation should occur at the parser and be captured early. If we reach consensus that we must always validate, the xml-checking can be left out, as we can then assumes a correct model. This will optimize processing.

Since:

MMBase-1.5

Version:

$Id: AbstractDove.java 35335 2009-05-21 08:14:41Z michiel $

Author:

Pierre van Rooden

Field Summary

static String	DESCENDANT
static String	DESCENDANTS
static String	DESCRIPTION
protected Document	doc The document that is being constructed.
static String	DOCTYPE_REQUEST
static String	DOCTYPE_RESPONSE
static String	ELM_CONTEXT
static String	ELM_CREATEDIR
static String	ELM_DESTINATION
static String	ELM_DESTINATIONTYPE
static String	ELM_DIRECTIONS
static String	ELM_ENCODING
static String	ELM_HREF
static String	ELM_ID
static String	ELM_LANG
static String	ELM_MAYDELETE
static String	ELM_MAYWRITE
static String	ELM_NAME
static String	ELM_NUMBER
static String	ELM_OLDNUMBER
static String	ELM_ORDERBY
static String	ELM_ROLE
static String	ELM_SEARCHDIR
static String	ELM_SEARCHTYPE
static String	ELM_SIZE
static String	ELM_SOURCE
static String	ELM_SOURCETYPE
static String	ELM_STATUS
static String	ELM_TYPE
static String	ELM_WHERE
static String	ELM_XPATH
static String	ERROR
static String	FIELD
static String	FIELDS
static String	GETCONSTRAINTS
static String	GETDATA
static String	GETLIST
static String	GETNEW
static String	GETNEWRELATION
static String	GETRELATIONS
static String	GUINAME
static String	GUITYPE
static String	IS_CLIENT
static String	IS_FALSE
static String	IS_PARSER
static String	IS_SERVER
static String	IS_TRUE
static String	MAXLENGTH
static String	NEW
static String	OBJECT
static String	ORIGINAL
static String	PARENT
static String	PLURALNAME
static String	PUT
static String	QUERY
static String	RELATION
static String	RELATIONS
static String	REQUEST
static String	REQUIRED
static String	RESPONSE
static String	SECURITY
static String	SECURITY_CLOUD
static String	SECURITY_METHOD
static String	SECURITY_NAME
static String	SECURITY_PASSWORD
static String	SINGULARNAME
protected static String[]	TYPE_DESCRIPTIONS

Constructor Summary

AbstractDove(Document doc)
Constructor

Method Summary

protected Element	addContentElement(String tagname, String content, Element out) Creates a DOM element which contains a Text Node, and adds it to the specified node as a child.
void	doRequest(Element in, Element out) Handles a request running one or more RPCs.
abstract void	doRequest(Element in, Element out, Cloud cloud, Map<String,byte[]> repository) Handles a request running one or more RPCs.
Element	executeRequest(Element in) This method executes the request from the editors, it can be invoked directly
Element	executeRequest(Element in, Cloud cloud, Map<String,byte[]> repository) This method executes the request from the editors, it can be invoked directly
protected Element	getFirstElement(Node item) Retrieves the first child node of an element that is itself an element.
protected Element	getFirstElement(Node item, String tagname) Retrieves the first child node of an element that is itself an element, and has the specified tagname.
protected Element	getNextElement(Node item) Retrieves the next sibling of an element that is itself an element.
protected Element	getNextElement(Node item, String tagname) Retrieves the the next sibling of an element that is itself an element, and has the specified tagname.
protected String	getTypeDescription(int type)

Methods inherited from class java.lang.Object

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

Field Detail

DOCTYPE_REQUEST

public static final String DOCTYPE_REQUEST

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DOCTYPE_RESPONSE

public static final String DOCTYPE_RESPONSE

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REQUEST

public static final String REQUEST

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RESPONSE

public static final String RESPONSE

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SECURITY

public static final String SECURITY

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GETDATA

public static final String GETDATA

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GETNEW

public static final String GETNEW

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GETNEWRELATION

public static final String GETNEWRELATION

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GETRELATIONS

public static final String GETRELATIONS

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GETCONSTRAINTS

public static final String GETCONSTRAINTS

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GETLIST

public static final String GETLIST

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PUT

public static final String PUT

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SECURITY_NAME

public static final String SECURITY_NAME

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SECURITY_PASSWORD

public static final String SECURITY_PASSWORD

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SECURITY_CLOUD

public static final String SECURITY_CLOUD

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SECURITY_METHOD

public static final String SECURITY_METHOD

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OBJECT

public static final String OBJECT

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FIELD

public static final String FIELD

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ORIGINAL

public static final String ORIGINAL

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NEW

public static final String NEW

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RELATIONS

public static final String RELATIONS

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RELATION

public static final String RELATION

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ERROR

public static final String ERROR

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QUERY

public static final String QUERY

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PARENT

public static final String PARENT

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DESCENDANTS

public static final String DESCENDANTS

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DESCENDANT

public static final String DESCENDANT

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SINGULARNAME

public static final String SINGULARNAME

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PLURALNAME

public static final String PLURALNAME

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DESCRIPTION

public static final String DESCRIPTION

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FIELDS

public static final String FIELDS

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GUINAME

public static final String GUINAME

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GUITYPE

public static final String GUITYPE

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MAXLENGTH

public static final String MAXLENGTH

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REQUIRED

public static final String REQUIRED

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ELM_ID

public static final String ELM_ID

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ELM_NUMBER

public static final String ELM_NUMBER

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ELM_OLDNUMBER

public static final String ELM_OLDNUMBER

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ELM_TYPE

public static final String ELM_TYPE

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ELM_SEARCHTYPE

public static final String ELM_SEARCHTYPE

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ELM_STATUS

public static final String ELM_STATUS

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ELM_NAME

public static final String ELM_NAME

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ELM_ROLE

public static final String ELM_ROLE

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ELM_DESTINATION

public static final String ELM_DESTINATION

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ELM_DESTINATIONTYPE

public static final String ELM_DESTINATIONTYPE

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ELM_SOURCETYPE

public static final String ELM_SOURCETYPE

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ELM_SEARCHDIR

public static final String ELM_SEARCHDIR

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ELM_CREATEDIR

public static final String ELM_CREATEDIR

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ELM_LANG

public static final String ELM_LANG

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ELM_XPATH

public static final String ELM_XPATH

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ELM_WHERE

public static final String ELM_WHERE

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ELM_ORDERBY

public static final String ELM_ORDERBY

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ELM_DIRECTIONS

public static final String ELM_DIRECTIONS

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ELM_SOURCE

public static final String ELM_SOURCE

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ELM_HREF

public static final String ELM_HREF

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ELM_MAYWRITE

public static final String ELM_MAYWRITE

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ELM_MAYDELETE

public static final String ELM_MAYDELETE

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ELM_CONTEXT

public static final String ELM_CONTEXT

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ELM_SIZE

public static final String ELM_SIZE

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ELM_ENCODING

public static final String ELM_ENCODING

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IS_PARSER

public static final String IS_PARSER

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IS_SERVER

public static final String IS_SERVER

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IS_CLIENT

public static final String IS_CLIENT

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IS_TRUE

public static final String IS_TRUE

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IS_FALSE

public static final String IS_FALSE

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TYPE_DESCRIPTIONS

protected static final String[] TYPE_DESCRIPTIONS

doc

protected final Document doc

The document that is being constructed. This should be used to construct new DOM elements.

Constructor Detail

AbstractDove

public AbstractDove(Document doc)

Constructor

Parameters:

doc - the Document that is constructed. This should only be used to construct new DOM elements. New (child) nodes should not be added to this document, but to the out element.

Method Detail

getTypeDescription

protected String getTypeDescription(int type)

addContentElement

protected Element addContentElement(String tagname,
                                    String content,
                                    Element out)

Creates a DOM element which contains a Text Node, and adds it to the specified node as a child. Used for creating field and error tags.

Parameters:

tagname - name of the new element

content - content of the new element as a string

out - the element to which to add the new Element.

Returns:

the newly created element

getFirstElement

protected Element getFirstElement(Node item)

Retrieves the first child node of an element that is itself an element. If none exist, it returns null.

Parameters:

item - the element to find the first child element of

Returns:

the first child element, or null.

getFirstElement

protected Element getFirstElement(Node item,
                                  String tagname)

Retrieves the first child node of an element that is itself an element, and has the specified tagname. If none exist, it returns null.

Parameters:

item - the element to find the first child element of

tagname - the tagname of the element desired

Returns:

the first child element, or null.

getNextElement

protected Element getNextElement(Node item)

Retrieves the next sibling of an element that is itself an element. If none exist, it returns null.

Parameters:

item - the element to find the sibling element of

Returns:

the sibling element, or null.

getNextElement

protected Element getNextElement(Node item,
                                 String tagname)

Retrieves the the next sibling of an element that is itself an element, and has the specified tagname. If none exist, it returns null.

Parameters:

item - the element to find the sibling element of

tagname - the tagname of the element desired

Returns:

the first child element, or null.

doRequest

public abstract void doRequest(Element in,
                               Element out,
                               Cloud cloud,
                               Map<String,byte[]> repository)

Handles a request running one or more RPCs. This method accepts a root DOM element, which should contain as it child nodes elements describing the call(s) to perform. Each element is an xml element with as the tagname the name of the call to run. Valid calls are getdata, getrelations, getlist, getconstraints, getnew, and put. The calls are redirected to the appropriate encapsulating method in this class. The end result of each call should be a DOM tree, built using the given parameters, which is then appended to the out element.
XXX:This method runs all commands in order of entrance. It does not currently check whether all child nodes refer to the same call. This means that it is possible to mix 'getdata' and 'getrelations' calls in one request. Ina dditon, it ignores calls it does not know how to handle. as described above, this should be handled by the xml parser. Note also that if no id was given for a call, a NullPointer exception is thrown.

Parameters:

in - the element that described the request (or input). The childnodes should describe the calls to perform.

out - the element that described the response (or return value). Results of calls should be added as childs to this element.

cloud - the MMCI cloud to use, if applicable.

repository - Repository that contains the blobs

doRequest

public void doRequest(Element in,
                      Element out)

Handles a request running one or more RPCs.

Parameters:

in - the element that described the request (or input). The childnodes should describe the calls to perform.

out - the element that described the response (or return value). Results of calls should be added as childs to this element.

executeRequest

public Element executeRequest(Element in,
                              Cloud cloud,
                              Map<String,byte[]> repository)

This method executes the request from the editors, it can be invoked directly

Parameters:

in - the element that described the request (or input). The childnodes should describe the calls to perform.

cloud - the MMCI cloud to use, if applicable.

repository - Repository that contains the blobs

Returns:

the element that described the response (or return value). Results of calls should be added as childs to this element.

executeRequest

public Element executeRequest(Element in)

This method executes the request from the editors, it can be invoked directly

Parameters:

in - the element that described the request (or input). The childnodes should describe the calls to perform.

Returns:

the element that described the response (or return value). Results of calls should be added as childs to this element.