Package org.apache.solr.handler.dataimport

Class Evaluator

java.lang.Object

org.apache.solr.handler.dataimport.Evaluator

Direct Known Subclasses:

DateFormatEvaluator, SolrQueryEscapingEvaluator, SqlEscapingEvaluator, UrlEvaluator

public abstract class Evaluator
extends Object

Pluggable functions for resolving variables

Implementations of this abstract class must provide a public no-arg constructor.

Refer to http://wiki.apache.org/solr/DataImportHandler for more details.

This API is experimental and may change in the future.

Since:

solr 1.3

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	Evaluator.VariableWrapper

Field Summary

Fields

Modifier and Type	Field	Description
static String	DATE_FORMAT_EVALUATOR
static String	ESCAPE_SOLR_QUERY_CHARS
static String	SQL_ESCAPE_EVALUATOR
static String	URL_ENCODE_EVALUATOR

Constructor Summary

Constructors

Constructor	Description
Evaluator()

Method Summary

Modifier and Type	Method	Description
abstract String	evaluate(String expression, Context context)	Return a String after processing an expression and a VariableResolver
protected Evaluator.VariableWrapper	getVariableWrapper(String s, VariableResolver vr)
protected List<Object>	parseParams(String expression, VariableResolver vr)	Parses a string of expression into separate params.

Methods inherited from class java.lang.Object

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

Field Detail

DATE_FORMAT_EVALUATOR

public static final String DATE_FORMAT_EVALUATOR

See Also:

Constant Field Values

URL_ENCODE_EVALUATOR

public static final String URL_ENCODE_EVALUATOR

See Also:

Constant Field Values

ESCAPE_SOLR_QUERY_CHARS

public static final String ESCAPE_SOLR_QUERY_CHARS

See Also:

Constant Field Values

SQL_ESCAPE_EVALUATOR

public static final String SQL_ESCAPE_EVALUATOR

See Also:

Constant Field Values

Constructor Detail

Evaluator

public Evaluator()

Method Detail

evaluate

public abstract String evaluate(String expression,
                                Context context)

Return a String after processing an expression and a VariableResolver

Parameters:

expression - string to be evaluated

context - instance

Returns:

the value of the given expression evaluated using the resolver

See Also:

VariableResolver

parseParams

protected List<Object> parseParams(String expression,
                                   VariableResolver vr)

Parses a string of expression into separate params. The values are separated by commas. each value will be translated into one of the following: <ol> <li>If it is in single quotes the value will be translated to a String</li> <li>If is is not in quotes and is a number a it will be translated into a Double</li> <li>else it is a variable which can be resolved and it will be put in as an instance of VariableWrapper</li> </ol>

Parameters:

expression - the expression to be parsed

vr - the VariableResolver instance for resolving variables

Returns:

a List of objects which can either be a string, number or a variable wrapper

getVariableWrapper

protected Evaluator.VariableWrapper getVariableWrapper(String s,
                                                       VariableResolver vr)