In the last blog post I gave a brief introduction into the integration of Elasticsearch¹ into AEM.

This followup will explain how the indexed data can be used in a search application in AEM. Although you can use every Elasticsearch client you want (e.g. the Java REST Client²), an easy way is the usage of one of the two Searches implemented in this package.

Both Search classes (Search.java³ and PageSearch.java⁴) require an instance of the ElasticSearchService⁵. Usually you would inject it using the @Reference Annotation⁶. Furthermore you have to choose, which index to use. {%highlight java %} Search search = new Search(myElasticSearchService, “myIndex”); {%endhighlight%}

Search

Generic searches on Elasticsearch Documents are implemented in the Search³ class.

Query

The most important part of a request is the query⁷. Currently basic querying is supported⁸, the syntax for most queries is similar. Usually the base for a query is a Bool Query⁹ that supports the following types:

Example queries:

// Simple query in field 'foo' for the term 'bar'
search.query().bool().must().term("foo","bar");

// Advanced query that requires two fields to match
Query must = search.query().bool().must();
must.terms("cq:template", "/apps/foo", "/apps/bar");
must.match("foo", "bar");

Filter

Filter¹⁰ are a special type of query as they also influence the results but do not change the score. The syntax is similar to a query:

// A search for all results where 'foo'= 'bar' which is filtered so all results
// also have 'ipsum' = 'lorem' or 'ipsum' = 'dolor'
Query must = search.query().bool().must();
must.query().term("foo", "bar");
must.filter().terms("ipsum","lorem", "dolor");

Limit the results

The following example constructs a search, which will include the first 10 results which have at least a score of 2.0.

search.size(10).minScore(2.0);

Another option is from which can be used for paging.

Sorting

If you want to sort¹¹ the results by a field, you can use the sort methods.

Sort sort = search.sort();
// Sort field 'foo' in descending order
sort.byField("foo").order(SortConstant.SortOrderConstant.DESC);
// Sort field 'bar' in ascending order
sort.byField("bar").order(SortConstant.SortOrderConstant.ASC);
// Sort field '_score' by default order
sort.byField("_score");

Highlighting

You can add one or more fields to the highlight¹² section. This will allow you, to show excerpts from the results.

Highlight highlight = search.highlight();
// highlight the 'foo' field
highlight.field("foo");

By default, all highlights are wrapped in <em> tags you can replace:

// use <span class="foobar"> instead of <em>
highlight.tags("<span class=\"foobar\">", "</span>");

PageSearch

As most searches require a similar base set, the PageSearch extends a Search with some AEM Page specific methods.

PageSearch pageSearch = new PageSearch(myElasticSearchService, "myIndex");
// Filter templates
pageSearch.templates("/apps/foo/bar/template", "/apps/foo/bar/template2");

// Search only pages with the given basepath
pageSearch.path("/content/foo/bar");

// Search by Page Title
pageSearch.title("My Page");

// Get newest pages first
pageSearch.newestFirst(true);

Footnotes