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+++
date = "2016-06-07T23:28:50-04:00"
title = "Text Search"
[menu.main]
parent = "Async Tutorials"
identifier = "Async Text Search"
weight = 80
pre = "<i class='fa'></i>"
+++
## Text Search
MongoDB supports query operations that perform a [text search]({{<docsref "text-search">}}) of string content. To perform text search, MongoDB uses a [text index]({{<docsref "core/index-text">}}) and the [`$text` query operator]({{<docsref "reference/operator/query/text">}}).
The Java driver provides the [`Filters.text()`]({{<apiref "com/mongodb/client/model/Filters.html#text-java.lang.String-com.mongodb.client.model.TextSearchOptions-">}}) helper to facilitate the creation of text search query filters.
## Prerequisites
- The example below requires a ``restaurants`` collection in the ``test`` database. To create and populate the collection, follow the directions in [github] (https://github.com/mongodb/docs-assets/tree/drivers).
- Include the following import statements:
```java
import com.mongodb.Block;
import com.mongodb.async.SingleResultCallback;
import com.mongodb.async.client.MongoClient;
import com.mongodb.async.client.MongoClients;
import com.mongodb.async.client.MongoCollection;
import com.mongodb.async.client.MongoDatabase;
import com.mongodb.client.model.*;
import org.bson.Document;
```
- Include the following code which the examples in the tutorials will use to print the results of the aggregation:
```java
Block<Document> printBlock = new Block<Document>() {
@Override
public void apply(final Document document) {
System.out.println(document.toJson());
}
};
```
## Connect to a MongoDB Deployment
Connect to a MongoDB deployment and declare and define a `MongoDatabase` and a `MongoCollection` instances.
For example, include the following code to connect to a standalone MongoDB deployment running on localhost on port `27017` and define `database` to refer to the `test` database and `collection` to refer to the `restaurants` collection:
```java
MongoClient mongoClient = MongoClients.create();
MongoDatabase database = mongoClient.getDatabase("test");
MongoCollection<Document> collection = database.getCollection("restaurants");
```
For additional information on connecting to MongoDB, see [Connect to MongoDB]({{< relref "driver-async/tutorials/connect-to-mongodb.md" >}}).
## Create the `text` Index
To create a [text index]({{<docsref "core/index-text">}}), use the [`Indexes.text`]({{< relref "builders/indexes.md#text-index">}})
static helper to create a specification for a text index and pass to [`MongoCollection.createIndex()`]({{<apiref "com/mongodb/client/MongoCollection.html#createIndex-org.bson.conversions.Bson-">}}) method.
The following example creates a text index on the `name` field for the `restaurants` collection.
```java
collection.createIndex(Indexes.text("name"), new SingleResultCallback<String>() {
@Override
public void onResult(final String result, final Throwable t) {
System.out.println("Operation Finished!");
}
});
```
## Perform Text Search
To perform text search, use the [`Filters.text()`]({{<apiref "com/mongodb/client/model/Filters.html#text-java.lang.String-com.mongodb.client.model.TextSearchOptions-">}}) helper to specify the text search query filter.
For example, the following code performs a text search on the `name` field for the word `"bakery"` or `"coffee"`.
```java
collection.count(Filters.text("bakery coffee"), new SingleResultCallback<Long>() {
@Override
public void onResult(final Long count, final Throwable t) {
System.out.println("Text search matches: " +count);
}
});
```
The example should print the following output:
```json
Text search matches: 2
```
For more information on the text search, see [`$text` operator]({{<docsref "reference/operator/query/text">}}).
### Text Score
For each matching document, text search assigns a score, representing the relevance of a document to the specified text search query filter. To return and sort by score, use the [`$meta`]({{< docsref "reference/operator/query/text/#sort-by-text-search-score">}}) operator in the projection document and the sort expression.
```java
collection.find(Filters.text("bakery cafe"))
.projection(Projections.metaTextScore("score"))
.sort(Sorts.metaTextScore("score"))
.forEach(printBlock, new SingleResultCallback<Void>() {
@Override
public void onResult(final Void result, final Throwable t) {
System.out.println("Operation Finished!");
}
});
```
### Specify a Text Search Option
The [`Filters.text()`]({{<apiref "com/mongodb/client/model/Filters.html#text-java.lang.String-com.mongodb.client.model.TextSearchOptions-">}}) helper can accept various [text search options]({{<docsref "reference/operator/query/text">}}). The Java driver provides [`TextSearchOptions`]({{<apiref "com/mongodb/client/model/TextSearchOptions.html">}}) class to specify these options.
For example, the following text search specifies the [text search language]({{<docsref "reference/text-search-languages">}}) option when performing text search for the word `cafe`:
```java
collection.count(Filters.text("cafe",
new TextSearchOptions().language("english")),
new SingleResultCallback<Long>() {
@Override
public void onResult(final Long count, final Throwable t) {
System.out.println("Text search matches: " +count);
}
});
```
The example should print the following output:
```json
Text search matches: 1
```
For more information about text search see the following sections in the MongoDB Server Manual:
- [`$text` query operator]({{< docsref "reference/operator/query/text">}})
- [`text` index]({{< docsref "core/index-text" >}})
- [Text Search Languages]({{<docsref "reference/text-search-languages">}})
|
