OpenSearch/docs/java-api/query-dsl/template-query.asciidoc

[[java-query-dsl-template-query]]
==== Template Query

See {ref}/search-template.html[Search Template] documentation

In order to use the `template` query from the Java API
the lang-mustache module dependency should be on the classpath and
the transport client should be loaded with the lang-mustache plugin:

[source,java]
--------------------------------------------------
TransportClient transportClient = TransportClient.builder()
        .settings(Settings.builder().put("node.name", "node"))
        .addPlugin(MustachePlugin.class)
        .build();
transportClient.addTransportAddress(
        new InetSocketTransportAddress(new InetSocketAddress(InetAddresses.forString("127.0.0.1"), 9300))
);
--------------------------------------------------

Define your template parameters as a `Map<String,Object>`:

[source,java]
--------------------------------------------------
Map<String, Object> template_params = new HashMap<>();
template_params.put("param_gender", "male");
--------------------------------------------------

You can use your stored search templates in `config/scripts`.
For example, if you have a file named `config/scripts/template_gender.mustache` containing:

[source,js]
--------------------------------------------------
{
    "template" : {
        "query" : {
            "match" : {
                "gender" : "{{param_gender}}"
            }
        }
    }
}
--------------------------------------------------

Define your template query:

[source,java]
--------------------------------------------------
QueryBuilder qb = new TemplateQueryBuilder(
    "gender_template",                  <1>
    ScriptService.ScriptType.FILE,      <2>
    template_params);                   <3>
--------------------------------------------------
<1> template name
<2> template stored on disk in `gender_template.mustache`
<3> parameters

You can also store your template in the cluster state:

[source,java]
--------------------------------------------------
client.admin().cluster().preparePutStoredScript()
    .setScriptLang("mustache")
    .setId("template_gender")
    .setSource(new BytesArray(
        "{\n" +
        "    \"template\" : {\n" +
        "        \"query\" : {\n" +
        "            \"match\" : {\n" +
        "                \"gender\" : \"{{param_gender}}\"\n" +
        "            }\n" +
        "        }\n" +
        "    }\n" +
        "}")).get();
--------------------------------------------------

To execute a stored templates, use `ScriptService.ScriptType.STORED`:

[source,java]
--------------------------------------------------
QueryBuilder qb = new TemplateQueryBuilder(
    "gender_template",                  <1>
    ScriptType.STORED,                  <2>
    template_params);                   <3>
--------------------------------------------------
<1> template name
<2> template stored in the cluster state
<3> parameters