The lookup searcher is a Lucene query generator using its query builder framework. It is made accessible via a servlet that is hosted on the Lookup's jetty HTTP server. The servlet provides:
- a HTML homepage with a search window
- a search API at
/api/search - an indexing API at
/api/index/run/api/index/clear
The example configuration used above looks as follows
version: "1.0"
indexPath: ./index
maxBufferedDocs: 1000000
logInterval: 1
exactMatchBoost: 10
prefixMatchBoost: 7
fuzzyMatchBoost: 1
fuzzyEditDistance: 2
fuzzyPrefixLength: 2
maxResults: 10000
format: JSON
minScore: 0.1
lookupFields:
- name: id
weight: 10
exact: true
highlight: false
tokenize: false
queryByDefault: false
- name: label
weight: 1
highlight: true
tokenize: true
allowPartialMatch: true
queryByDefault: true
- name: comment
weight: .2
highlight: true
tokenize: true
allowPartialMatch: true
queryByDefault: trueThe configuration holds a path to the index structure that will be used for searching along with a list of variables used for scoring results. Please refer to the configuration documentation for more detailed explanations.
The queryFields variable holds the most important information with a list of objects describing fields that the searcher can potentially include in the search. Each query field spefifies a field name that should be present in the index structure (as specified in the index configuration). Each field can be given default settings for score weights and other properties, such as an indicator if query inputs should be tokenized for a specific field.
The index path points to the directory holding the index structure (absolute or relative to the configuration file). This is usually the folder containing the result of the lookup indexer.
Denotes a multiplier that is applied to any result score if the search term matches a document field value exactly. Can be overriden via HTTP query parameter (e.g. ...&exactMatchBoost=100).
Denotes a multiplier this is applied to any result score if the search term is a prefix of a document field value. Can be overriden via HTTP query parameter (e.g. ...&prefixMatchBoost=100).
Denotes a multiplier this is applied to any result score if the search term roughly matches a document field value. Can be overriden via HTTP query parameter (e.g. ...&fuzzyMatchBoost=100).
Denotes the maximum edit distance between a search input and a document field such that it is still considered a fuzzy match.
This is the number of characters at the start of a term that must be identical (not fuzzy) to the query term if the query is to match that term.
Configuration value passed to the lucene indexer (see setMaxBufferedDocs()).
The maximum number of results. Can be overriden via HTTP query parameter (e.g. ...&maxResults=10)
The format of the results. Defaults to JSON and can be one of the following:
Returns the result as JSON which includes highlighting tags in matched strings.
Returns the result as JSON without any highlighting tags.
Returns the result as JSON with highlighted and non-highlighted strings.
Returns the result as XML.
When the selected format is XML you can provide the path to an XSL template to transform the result into any desired XML output.
The minimum score that a potential search result has to reach in order to be included in the result set. Can be overriden via HTTP query parameter (e.g. ...&minScore=10).
[Optional] An mathematical function that will be applied to result documents based on any numeric field indexed to that document.
A list of objects describing the query fields on which the searcher will operate. The objects consist of the following subfields:
The name of the field. The field name can be used as a query parameter.
The type of the field (see Field Types).
A list of strings specifying alternative names for a field name
A numerical weight that is applied to a match on the respective field. E.g. can be used to express, that a match on a title field is worth more than a match on an abstract field. Can be overriden via HTTP query parameter using the field name followed by the string Weight (e.g. ...&labelWeight=true when searching on the field label).
Denotes whether the result should include special html tags highlighting the match between the query string and the field value. Defaults to false. Can be overriden via HTTP query parameter using the field name followed by the string Highlight (e.g. ...&labelHighlight=true when searching on the field label).
If true, the query string will be tokenized and each token will be matched against the field value of this field. Tokenization includes, for instance, splitting of input strings by whitespaces. If set to false, the input will be matched against the document fields as is. Defaults to false. Can be overriden via HTTP query parameter using the field name followed by the string Tokenize (e.g. ...&labelTokenize=true when searching on the field label).
If true, a match on this field is required. A document that has a match on any other field included in the search but does not have a match on this field, will be dropped from the result set even if it would have been included otherwise. Defaults to false. Can be overriden via HTTP query parameter using the field name followed by the string Required (e.g. ...&labelRequired=true when searching on the field label).
If true, a match on this field only counts if the field value matches the query string exactly. In that case, fuzzy and prefix matching will not be applied. Defaults to false. Can be overriden via HTTP query parameter using the field name followed by the string Exact (e.g. ...&labelExact=true when searching on the field label).
Before matching against a field, the query string can be tokenized. If allowPartialMatch is set to false, a field will only count as matched if all query tokens match the field. If true, the field will match if at least one query token matches the field. Can be overriden via HTTP query parameter using the field name followed by the string AllowPartialMatch (e.g. ...&labelAllowPartialMatch=true when searching on the field label).
If true, all queries sent with the query parameter will be matched against this field.
The most important parameter: the search query string. The query string will be matched against all fields configured as queryByDefault.
Any configured field name can be used as a query parameter. The string specified with this parameter will only be matched against the respective field.
Float value. See weight.
Boolean value. See exact.
Boolean value. See required.
Boolean value. See allowPartialMatch.
Boolean value. See tokenize.
Boolean value. See highlight.
Join can specify any indexed field. The search will then be executed normally but the initial result set will not be returned. Instead, Lucene will return all documents that have a value for the specified field equal to any document id in the initial result set (simplified Lucene join).
Float value. See exactMatchBoost
Float value. See prefixMatchBoost
Float value. See fuzzyMatchBoost
Int value. See fuzzyEditDistance
Int value. See fuzzyPrefixLength
See maxResults
See format
When indexing and searching it is sometimes important to explicitly set the type of a field. This will keep the indexer from tokenizing URIs or allow it to run min/max queries on numeric values. The field type can be set to the following values:
The field will be indexed and tokenized, which is useful for indexing any text with multiple words. Search queries can then return matches for each word.
The field will be indexed but not tokenized or changed in any way. Useful for uris or other identifiers that should only match in its entirety. Uses the UriAnalzyer.
The field will be indexed but not tokenized. The field value will be indexed in its lowercase form. StringPhraseAnalyzer.
Creates a field that is stored but not indexed. No changes to the string are applied.
Uses the NGramAnalyzer to tokenize strings into ngrams of lengths between 3 and 5 characters.
Saves the file as a numeric field. Numeric field can be used in arithmetic operations during query time. Additionally, numeric fields can be included as variables in the global boost formula