java.lang.Object
- com.yahoo.prelude.query.Item

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

CompositeItem, FalseItem, NullItem, PureWeightedItem, SimpleTaggableItem
```
public abstract class Item
extends java.lang.Object
implements java.lang.Cloneable
```
A term of the query language. As "term" is also the common term (sorry) for a literal to be found (or not) in a search index, the term item is used for query language terms.

The query is represented as a composite tree of Item subclasses. This allow arbitrary complex combinations of ands, nots, phrases and so on.

Items are in general mutable and not thread safe.

Author:

bratseth, havardpe

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`Item.ItemCreator`	The definitions in Item.ItemCreator must match the ones in searchlib/src/searchlib/parsequery/parse.h
`static class`	`Item.ItemType`	The definitions in Item.ItemType must match the ones in searchlib/src/searchlib/parsequery/parse.h

Field Summary

Fields
Modifier and Type	Field	Description
`protected Item`	`connectedBacklink`
`protected Item`	`connectedItem`	Items for explicit connectivity
`protected double`	`connectivity`
`static int`	`DEFAULT_WEIGHT`
`protected boolean`	`explicitSignificance`
`protected double`	`significance`	Explicit term significance
`protected int`	`uniqueID`	Unique identifier to address the item for external annotation

Constructor Summary

Constructors
Constructor Description

Item()

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addAnnotation(java.lang.String key, java.lang.Object value)`	Annotate this item
`protected abstract void`	`appendBodyString(java.lang.StringBuilder buffer)`	Override to append the item body in the canonical query language of this item.
`protected void`	`appendHeadingString(java.lang.StringBuilder buffer)`	Appends the heading of this string.
`Item`	`clone()`	Returns a deep copy of this item
`void`	`disclose(Discloser discloser)`
`abstract int`	`encode(java.nio.ByteBuffer buffer)`
`protected void`	`encodeThis(java.nio.ByteBuffer buffer)`
`boolean`	`equals(java.lang.Object object)`	Returns whether this item is of the same class and contains the same state as the given item
`java.lang.Object`	`getAnnotation(java.lang.String annotation)`	Returns an annotation on this item, or null if the annotation is not set
`protected static byte[]`	`getBytes(java.lang.String string)`	Utility method for turning a string into utf-8 bytes
`int`	`getCode()`	Returns the int code of this item
`Item.ItemCreator`	`getCreator()`	Returns the item creator value.
`abstract Item.ItemType`	`getItemType()`	Return the enumerated type of this item.
`java.lang.String`	`getLabel()`	Returns the label for this item.
`com.yahoo.language.Language`	`getLanguage()`	Returns the language of any natural language text below this item, or Language.UNKNOWN if not set.
`abstract java.lang.String`	`getName()`	Returns the name of this item
`CompositeItem`	`getParent()`	Returns the parent in the query tree, or null if this node has no parent
`abstract int`	`getTermCount()`
`int`	`getWeight()`	Returns the relative importance of this term.
`boolean`	`hasAnnotation(java.lang.String annotation)`	Returns whether this has an annotation
`boolean`	`hasConnectivityBackLink()`	DO NOT USE
`int`	`hashCode()`
`protected boolean`	`hasUniqueID()`
`boolean`	`isFilter()`	Returns whether this is a filter term
`boolean`	`isFromSpecialToken()`
`boolean`	`isProtected()`	Returns whether this is to be protected from change/remove by query rewriters.
`boolean`	`isRanked()`	Returns whether or not this item should affect ranking.
`boolean`	`isRoot()`	Returns true if this is the root item - that is if the parent is the QueryTree (or null for legacy reasons)
`static void`	`putBytes(byte[] bytes, java.nio.ByteBuffer buffer)`
`static void`	`putString(java.lang.String s, java.nio.ByteBuffer buffer)`
`void`	`setCreator(Item.ItemCreator creator)`	Sets the item creator value.
`void`	`setFilter(boolean filter)`	Sets whether this is a filter term.
`void`	`setFromSpecialToken(boolean fromSpecialToken)`
`protected void`	`setHasUniqueID(boolean hasUniqueID)`
`abstract void`	`setIndexName(java.lang.String index)`	Sets the index name of this item
`void`	`setLabel(java.lang.String label)`	Label this item with a symbolic name which can later be used by the back-end to identify specific items for ranking purposes.
`void`	`setLanguage(com.yahoo.language.Language language)`	Sets the language of any natural language text below this item.
`void`	`setParent(CompositeItem parent)`	Sets the parent in the tree.
`void`	`setPositionData(boolean usePositionData)`	Sets whether or not position data should be used when ranking this term item.
`void`	`setProtected(boolean isProtected)`	Set whether this should be protected from change/remove by query rewriters
`void`	`setRanked(boolean isRanked)`	Sets whether or not this term item should affect ranking.
`void`	`setWeight(int w)`	Sets the relative importance of this term
`protected boolean`	`shouldParenthize()`	Returns whether or not this item should be parethized when printed.
`java.lang.String`	`toString()`	Returns the canonical query language string of this item.
`boolean`	`usePositionData()`	Returns whether or not position data should be used when ranking this item

Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - DEFAULT_WEIGHT
```
public static final int DEFAULT_WEIGHT
```
    See Also:
    
    Constant Field Values
  - uniqueID
```
protected int uniqueID
```
    Unique identifier to address the item for external annotation
  - connectedItem
```
protected Item connectedItem
```
    Items for explicit connectivity
  - connectedBacklink
```
protected Item connectedBacklink
```
  - connectivity
```
protected double connectivity
```
  - significance
```
protected double significance
```
    Explicit term significance
  - explicitSignificance
```
protected boolean explicitSignificance
```
- Constructor Detail
  - Item
```
public Item()
```
- Method Detail
  - setIndexName
```
public abstract void setIndexName(java.lang.String index)
```
    Sets the index name of this item
  - getCode
```
public final int getCode()
```
    Returns the int code of this item
  - getItemType
```
public abstract Item.ItemType getItemType()
```
    Return the enumerated type of this item.
  - getName
```
public abstract java.lang.String getName()
```
    Returns the name of this item
  - setFilter
```
public void setFilter(boolean filter)
```
    Sets whether this is a filter term. This indicates that the term origins from the filter parameter in the search API. The search backend does not handle filter terms any different than non-filter terms.
  - isFilter
```
public boolean isFilter()
```
    Returns whether this is a filter term
  - getCreator
```
public Item.ItemCreator getCreator()
```
    Returns the item creator value.
  - setCreator
```
public void setCreator(Item.ItemCreator creator)
```
    Sets the item creator value.
  - setWeight
```
public void setWeight(int w)
```
    Sets the relative importance of this term
  - getWeight
```
public int getWeight()
```
    Returns the relative importance of this term. Default is 100.
  - addAnnotation
```
public void addAnnotation(java.lang.String key,
                          java.lang.Object value)
```
    Annotate this item
    
    Parameters:
    
    key - the annotation key
    
    value - the value, or null to set a valueless annotation
  - getAnnotation
```
public java.lang.Object getAnnotation(java.lang.String annotation)
```
    Returns an annotation on this item, or null if the annotation is not set
  - hasAnnotation
```
public boolean hasAnnotation(java.lang.String annotation)
```
    Returns whether this has an annotation
  - setProtected
```
public void setProtected(boolean isProtected)
```
    Set whether this should be protected from change/remove by query rewriters
  - isProtected
```
public boolean isProtected()
```
    Returns whether this is to be protected from change/remove by query rewriters. default is false
  - setParent
```
public void setParent(CompositeItem parent)
```
    Sets the parent in the tree. Do not use: Only to be called from CompositeItem/QueryTree
  - getParent
```
public CompositeItem getParent()
```
    Returns the parent in the query tree, or null if this node has no parent
  - encode
```
public abstract int encode(java.nio.ByteBuffer buffer)
```
  - encodeThis
```
protected void encodeThis(java.nio.ByteBuffer buffer)
```
  - getBytes
```
protected static final byte[] getBytes(java.lang.String string)
```
    Utility method for turning a string into utf-8 bytes
  - putString
```
public static void putString(java.lang.String s,
                             java.nio.ByteBuffer buffer)
```
  - putBytes
```
public static void putBytes(byte[] bytes,
                            java.nio.ByteBuffer buffer)
```
  - getTermCount
```
public abstract int getTermCount()
```
  - toString
```
public java.lang.String toString()
```
    Returns the canonical query language string of this item.
    
    The canonical language represent an item by the string
    ([itemName] [body])
    where the body may recursively be other items.
    TODO: Change the output query language into a canonical form of the input query language
    Overrides:
    
    toString in class java.lang.Object
  - shouldParenthize
```
protected boolean shouldParenthize()
```
    Returns whether or not this item should be parethized when printed. Default is false - no parentheses
  - appendHeadingString
```
protected void appendHeadingString(java.lang.StringBuilder buffer)
```
    Appends the heading of this string. As default getName() followed by a space.
  - appendBodyString
```
protected abstract void appendBodyString(java.lang.StringBuilder buffer)
```
    Override to append the item body in the canonical query language of this item. An item is usually represented by the string
    ([itemName] [body])
    The body must be appended appended by this method.
  - clone
```
public Item clone()
```
    Returns a deep copy of this item
    
    Overrides:
    
    clone in class java.lang.Object
  - equals
```
public boolean equals(java.lang.Object object)
```
    Returns whether this item is of the same class and contains the same state as the given item
    
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - hasUniqueID
```
protected boolean hasUniqueID()
```
  - setHasUniqueID
```
protected void setHasUniqueID(boolean hasUniqueID)
```
  - setLabel
```
public void setLabel(java.lang.String label)
```
    Label this item with a symbolic name which can later be used by the back-end to identify specific items for ranking purposes.
    
    Parameters:
    
    label - label for this item
  - getLabel
```
public java.lang.String getLabel()
```
    Returns the label for this item. This method will return null if no label has been set.
  - setRanked
```
public void setRanked(boolean isRanked)
```
    Sets whether or not this term item should affect ranking. If set to false this term is not exposed to the ranking framework in the search backend.
  - isRanked
```
public boolean isRanked()
```
    Returns whether or not this item should affect ranking.
  - setPositionData
```
public void setPositionData(boolean usePositionData)
```
    Sets whether or not position data should be used when ranking this term item. If set to false the search backend uses fast bit vector data structures when matching on this term and only a few simple ranking features will be available when ranking this term. Note that setting this to false also saves a lot of CPU during matching as bit vector data structures are used.
  - usePositionData
```
public boolean usePositionData()
```
    Returns whether or not position data should be used when ranking this item
  - disclose
```
public void disclose(Discloser discloser)
```
  - isFromSpecialToken
```
public boolean isFromSpecialToken()
```
  - setFromSpecialToken
```
public void setFromSpecialToken(boolean fromSpecialToken)
```
  - getLanguage
```
public com.yahoo.language.Language getLanguage()
```
    Returns the language of any natural language text below this item, or Language.UNKNOWN if not set.
  - setLanguage
```
public void setLanguage(com.yahoo.language.Language language)
```
    Sets the language of any natural language text below this item. This cannot be set to null but can be set to Language.UNKNOWN
  - hasConnectivityBackLink
```
public boolean hasConnectivityBackLink()
```
    DO NOT USE
  - isRoot
```
public boolean isRoot()
```
    Returns true if this is the root item - that is if the parent is the QueryTree (or null for legacy reasons)

Class Item

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_WEIGHT

uniqueID

connectedItem

connectedBacklink

connectivity

significance

explicitSignificance

Constructor Detail

Item

Method Detail

setIndexName

getCode

getItemType

getName

setFilter

isFilter

getCreator

setCreator

setWeight

getWeight

addAnnotation

getAnnotation

hasAnnotation

setProtected

isProtected

setParent

getParent

encode

encodeThis

getBytes

putString

putBytes

getTermCount

toString

shouldParenthize

appendHeadingString

appendBodyString

clone

equals

hashCode

hasUniqueID

setHasUniqueID

setLabel

getLabel

setRanked

isRanked

setPositionData

usePositionData

disclose

isFromSpecialToken

setFromSpecialToken

getLanguage

setLanguage

hasConnectivityBackLink

isRoot