SimpleQueryParser (Lucene 5.5.2 API)

java.lang.Object
- org.apache.lucene.util.QueryBuilder
- - org.apache.lucene.queryparser.simple.SimpleQueryParser

```
public class SimpleQueryParser
extends QueryBuilder
```
SimpleQueryParser is used to parse human readable query syntax.
The main idea behind this parser is that a person should be able to type whatever they want to represent a query, and this parser will do its best to interpret what to search for no matter how poorly composed the request may be. Tokens are considered to be any of a term, phrase, or subquery for the operations described below. Whitespace including ' ' '\n' '\r' and '\t' and certain operators may be used to delimit tokens ( ) + | " .
Any errors in query syntax will be ignored and the parser will attempt to decipher what it can; however, this may mean odd or unexpected results.
Query Operators
- '+' specifies AND operation: token1+token2
- '|' specifies OR operation: token1|token2
- '-' negates a single token: -token0
- '"' creates phrases of terms: "term1 term2 ..."
- '*' at the end of terms specifies prefix query: term*
- '~N' at the end of terms specifies fuzzy query: term~1
- '~N' at the end of phrases specifies near query: "term1 term2"~5
- '(' and ')' specifies precedence: token1 + (token2 | token3)
The default operator is OR if no other operator is specified. For example, the following will OR token1 and token2 together: token1 token2
Normal operator precedence will be simple order from right to left. For example, the following will evaluate token1 OR token2 first, then AND with token3:
token1 | token2 + token3
Escaping
An individual term may contain any possible character with certain characters requiring escaping using a '\'. The following characters will need to be escaped in terms and phrases: + | " ( ) ' \
The '-' operator is a special case. On individual terms (not phrases) the first character of a term that is - must be escaped; however, any '-' characters beyond the first character do not need to be escaped. For example:
- -term1 -- Specifies NOT operation against term1
- \-term1 -- Searches for the term -term1.
- term-1 -- Searches for the term term-1.
- term\-1 -- Searches for the term term-1.
The '*' operator is a special case. On individual terms (not phrases) the last character of a term that is '*' must be escaped; however, any '*' characters before the last character do not need to be escaped:
- term1* -- Searches for the prefix term1
- term1\* -- Searches for the term term1*
- term*1 -- Searches for the term term*1
- term\*1 -- Searches for the term term*1
Note that above examples consider the terms before text processing.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`AND_OPERATOR` Enables `AND` operator (+)
`static int`	`ESCAPE_OPERATOR` Enables `ESCAPE` operator (\)
`protected int`	`flags` flags to the parser (to turn features on/off)
`static int`	`FUZZY_OPERATOR` Enables `FUZZY` operators: (~) on single terms
`static int`	`NEAR_OPERATOR` Enables `NEAR` operators: (~) on phrases
`static int`	`NOT_OPERATOR` Enables `NOT` operator (-)
`static int`	`OR_OPERATOR` Enables `OR` operator (\|)
`static int`	`PHRASE_OPERATOR` Enables `PHRASE` operator (")
`static int`	`PRECEDENCE_OPERATORS` Enables `PRECEDENCE` operators: `(` and `)`
`static int`	`PREFIX_OPERATOR` Enables `PREFIX` operator (*)
`protected Map<String,Float>`	`weights` Map of fields to query against with their weights
`static int`	`WHITESPACE_OPERATOR` Enables `WHITESPACE` operators: ' ' '\n' '\r' '\t'

Constructor Summary

Constructors
Constructor and Description
`SimpleQueryParser(Analyzer analyzer, Map<String,Float> weights)` Creates a new parser searching over multiple fields with different weights.
`SimpleQueryParser(Analyzer analyzer, Map<String,Float> weights, int flags)` Creates a new parser with custom flags used to enable/disable certain features.
`SimpleQueryParser(Analyzer analyzer, String field)` Creates a new parser searching over a single field.

Method Summary

Methods
Modifier and Type	Method and Description
`BooleanClause.Occur`	`getDefaultOperator()` Returns the implicit operator setting, which will be either `SHOULD` or `MUST`.
`protected Query`	`newDefaultQuery(String text)` Factory method to generate a standard query (no phrase or prefix operators).
`protected Query`	`newFuzzyQuery(String text, int fuzziness)` Factory method to generate a fuzzy query.
`protected Query`	`newPhraseQuery(String text, int slop)` Factory method to generate a phrase query with slop.
`protected Query`	`newPrefixQuery(String text)` Factory method to generate a prefix query.
`Query`	`parse(String queryText)` Parses the query text and returns parsed query
`void`	`setDefaultOperator(BooleanClause.Occur operator)` Sets the implicit operator setting, which must be either `SHOULD` or `MUST`.
`protected Query`	`simplify(BooleanQuery bq)` Helper to simplify boolean queries with 0 or 1 clause

Methods inherited from class org.apache.lucene.util.QueryBuilder
createBooleanQuery, createBooleanQuery, createFieldQuery, createMinShouldMatchQuery, createPhraseQuery, createPhraseQuery, getAnalyzer, getEnablePositionIncrements, newBooleanQuery, newMultiPhraseQuery, newTermQuery, setAnalyzer, setEnablePositionIncrements

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - weights
```
protected final Map<String,Float> weights
```
    Map of fields to query against with their weights
  - flags
```
protected final int flags
```
    flags to the parser (to turn features on/off)
  - AND_OPERATOR
```
public static final int AND_OPERATOR
```
    Enables AND operator (+)
    
    See Also:
    Constant Field Values
  - NOT_OPERATOR
```
public static final int NOT_OPERATOR
```
    Enables NOT operator (-)
    
    See Also:
    Constant Field Values
  - OR_OPERATOR
```
public static final int OR_OPERATOR
```
    Enables OR operator (|)
    
    See Also:
    Constant Field Values
  - PREFIX_OPERATOR
```
public static final int PREFIX_OPERATOR
```
    Enables PREFIX operator (*)
    
    See Also:
    Constant Field Values
  - PHRASE_OPERATOR
```
public static final int PHRASE_OPERATOR
```
    Enables PHRASE operator (")
    
    See Also:
    Constant Field Values
  - PRECEDENCE_OPERATORS
```
public static final int PRECEDENCE_OPERATORS
```
    Enables PRECEDENCE operators: ( and )
    
    See Also:
    Constant Field Values
  - ESCAPE_OPERATOR
```
public static final int ESCAPE_OPERATOR
```
    Enables ESCAPE operator (\)
    
    See Also:
    Constant Field Values
  - WHITESPACE_OPERATOR
```
public static final int WHITESPACE_OPERATOR
```
    Enables WHITESPACE operators: ' ' '\n' '\r' '\t'
    
    See Also:
    Constant Field Values
  - FUZZY_OPERATOR
```
public static final int FUZZY_OPERATOR
```
    Enables FUZZY operators: (~) on single terms
    
    See Also:
    Constant Field Values
  - NEAR_OPERATOR
```
public static final int NEAR_OPERATOR
```
    Enables NEAR operators: (~) on phrases
    
    See Also:
    Constant Field Values
- Constructor Detail
  - SimpleQueryParser
```
public SimpleQueryParser(Analyzer analyzer,
                 String field)
```
    Creates a new parser searching over a single field.
  - SimpleQueryParser
```
public SimpleQueryParser(Analyzer analyzer,
                 Map<String,Float> weights)
```
    Creates a new parser searching over multiple fields with different weights.
  - SimpleQueryParser
```
public SimpleQueryParser(Analyzer analyzer,
                 Map<String,Float> weights,
                 int flags)
```
    Creates a new parser with custom flags used to enable/disable certain features.
- Method Detail
  - parse
```
public Query parse(String queryText)
```
    Parses the query text and returns parsed query
  - newDefaultQuery
```
protected Query newDefaultQuery(String text)
```
    Factory method to generate a standard query (no phrase or prefix operators).
  - newFuzzyQuery
```
protected Query newFuzzyQuery(String text,
                  int fuzziness)
```
    Factory method to generate a fuzzy query.
  - newPhraseQuery
```
protected Query newPhraseQuery(String text,
                   int slop)
```
    Factory method to generate a phrase query with slop.
  - newPrefixQuery
```
protected Query newPrefixQuery(String text)
```
    Factory method to generate a prefix query.
  - simplify
```
protected Query simplify(BooleanQuery bq)
```
    Helper to simplify boolean queries with 0 or 1 clause
  - getDefaultOperator
```
public BooleanClause.Occur getDefaultOperator()
```
    Returns the implicit operator setting, which will be either SHOULD or MUST.
  - setDefaultOperator
```
public void setDefaultOperator(BooleanClause.Occur operator)
```
    Sets the implicit operator setting, which must be either SHOULD or MUST.

Class SimpleQueryParser

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.lucene.util.QueryBuilder

Methods inherited from class java.lang.Object

Field Detail

weights

flags

AND_OPERATOR

NOT_OPERATOR

OR_OPERATOR

PREFIX_OPERATOR

PHRASE_OPERATOR

PRECEDENCE_OPERATORS

ESCAPE_OPERATOR

WHITESPACE_OPERATOR

FUZZY_OPERATOR

NEAR_OPERATOR

Constructor Detail

SimpleQueryParser

SimpleQueryParser

SimpleQueryParser

Method Detail

parse

newDefaultQuery

newFuzzyQuery

newPhraseQuery

newPrefixQuery

simplify

getDefaultOperator

setDefaultOperator