com.attivio.sdk.search.fields

Class FieldExpression

java.lang.Object

com.attivio.sdk.search.fields.FieldExpression

All Implemented Interfaces:

Serializable, Cloneable

Direct Known Subclasses:

BinaryFieldExpression, Condition, Constant, CurrentTime, DocBoost, FieldLength, Locate, MatchingFields, MatchingTerms, MultiaryFieldExpression, NumDocs, PartitionId, PhraseMatch, PhraseScore, QueryParameter, ScopeField, ScopeFrequency, ScoreExplain, StoredField, Switch, TotalScopeFrequency, TotalTermFrequency, UnaryFieldExpression, UserDefinedField

public abstract class FieldExpression
extends Object
implements Cloneable, Serializable

Base class for field expressions.

A FieldExpression represents a column or field that is returned in a SearchDocument. Each field expression can have an "alias" specified for it. If an "alias" is specified for the field expression, the name of the field in the returned SearchDocument will be the specified alias. If an alias is not specified, then a default alias will be used.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	FieldExpression.StringMode Mode for serializing FieldExpression to a string.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	alias The alias for this expression.
protected static FieldExpression[]	EMPTY_ARRAY Empty array of field expressions.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FieldExpression() Construct a new FieldExpression using the default alias.
	FieldExpression(String alias) Construct a new FieldExpression with an alias.

Method Summary

Modifier and Type	Method and Description
FieldExpression	as(String aliasx) Set the alias and return this FieldExpression.
FieldExpression	clone()
boolean	containsAlias() Returns true if an alias is specified for this expression.
static FieldExpression[]	copyOf(FieldExpression[] args, int length) Create a copy of args.
boolean	equals(Object other)
abstract boolean	equalsIgnoreAlias(FieldExpression other) Returns true if other is the same as this, with the exception of alias.
protected static boolean	equalsIgnoreAlias(FieldExpression a, FieldExpression b) Null safe equivalent to a.equalsIgnoreAlias(b)
String	getAlias() Get the alias.
String	getDefaultAlias() Get the default alias to use for this FieldExpression.
String	getFieldName() Get the field name for this expression.
abstract SchemaField.Type	getType(Schema schema) Resolve the type for this expression.
protected static FieldExpression	handleFieldExpression(FieldExpressionHandler handler, FieldExpression input)
abstract boolean	hasChildren() Returns true if this field expression has any sub FieldExpressions.
int	hashCode()
abstract boolean	isConstant() Returns true if this field expression evaluates to a constant value.
protected static boolean	isConstant(FieldExpression value)
protected static void	quote(StringBuilder buffer, String text) Add text to buffer as quoted string.
void	rewrite(QueryHandler handler, boolean recursive) Rewrite any query objects in this FieldExpression using handler.
protected static void	rewrite(QueryHandler handler, boolean recursive, FieldExpression input)
abstract FieldExpression	rewriteChildren(FieldExpressionHandler handler) Traverse this FieldExpression using handler to visit/rewrite direct child elements if this expression.
void	setAlias(String alias) Set the alias.
String	toString() Return String representation of expression.
void	toString(StringBuilder buffer) Writes the string representation of this field expression to buffer.
protected abstract void	toString(StringBuilder buffer, FieldExpression.StringMode mode) Writes the string representation of this field expression to buffer.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_ARRAY

protected static final FieldExpression[] EMPTY_ARRAY

Empty array of field expressions.

alias

protected String alias

The alias for this expression.

Constructor Detail

FieldExpression

protected FieldExpression()

Construct a new FieldExpression using the default alias.

FieldExpression

public FieldExpression(String alias)

Construct a new FieldExpression with an alias.

Method Detail

getType

public abstract SchemaField.Type getType(Schema schema)

Resolve the type for this expression.

isConstant

public abstract boolean isConstant()

Returns true if this field expression evaluates to a constant value.

containsAlias

public boolean containsAlias()

Returns true if an alias is specified for this expression.

getDefaultAlias

public final String getDefaultAlias()

Get the default alias to use for this FieldExpression.

getAlias

public String getAlias()

Get the alias. This will be the field name of SearchField created from this expression.

setAlias

public void setAlias(String alias)

Set the alias.

as

public FieldExpression as(String aliasx)

Set the alias and return this FieldExpression.

Useful for call chaining new ExpressionClass(arg).as("alias").

getFieldName

public String getFieldName()

Get the field name for this expression.

This is used as a hint to the search engine to tie back to the schema. null may be returned if this expression contains no field. If this expression is composed of many fields, this can be either the "primary" field for the expression, or null.

hasChildren

public abstract boolean hasChildren()

Returns true if this field expression has any sub FieldExpressions.

rewriteChildren

public abstract FieldExpression rewriteChildren(FieldExpressionHandler handler)

Traverse this FieldExpression using handler to visit/rewrite direct child elements if this expression.

NOTE: this method traverses direct child expressions (if any) only.

rewrite

public void rewrite(QueryHandler handler,
                    boolean recursive)

Rewrite any query objects in this FieldExpression using handler.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public final String toString()

Return String representation of expression.

Overrides:

toString in class Object

toString

public final void toString(StringBuilder buffer)

Writes the string representation of this field expression to buffer.

NOTE: the alias will not be written to buffer by this function.

toString

protected abstract void toString(StringBuilder buffer,
                                 FieldExpression.StringMode mode)

Writes the string representation of this field expression to buffer.

NOTE: the alias will not be written to buffer by this function.

quote

protected static void quote(StringBuilder buffer,
                            String text)

Add text to buffer as quoted string.

NOTE: value will only be quoted if it contains non-alphanumeric characters.

equals

public final boolean equals(Object other)

Overrides:

equals in class Object

equalsIgnoreAlias

public abstract boolean equalsIgnoreAlias(FieldExpression other)

Returns true if other is the same as this, with the exception of alias.

equalsIgnoreAlias

protected static boolean equalsIgnoreAlias(FieldExpression a,
                                           FieldExpression b)

Null safe equivalent to a.equalsIgnoreAlias(b)

clone

public FieldExpression clone()

Overrides:

clone in class Object

isConstant

protected static boolean isConstant(FieldExpression value)

handleFieldExpression

protected static FieldExpression handleFieldExpression(FieldExpressionHandler handler,
                                                       FieldExpression input)

rewrite

protected static void rewrite(QueryHandler handler,
                              boolean recursive,
                              FieldExpression input)

copyOf

public static final FieldExpression[] copyOf(FieldExpression[] args,
                                             int length)

Create a copy of args.