Springboot2. x integrates with the distributed search engine Elasticsearch

1. Introduction

Elasticsearch is one of the most popular search engines for Elasticsearch in the world. Elasticsearch is one of the most popular search engines for Elasticsearch in the world

2. Elasticsearch is introduced

Elasticsearch is a distributed search engine that stores, analyzes, and searches data.

3. Elasticsearch installation

3.1 Installing Elasticsearch in Docker Mode

3.1.1 Using Docker to Search for Images

➜  ~ docker search elasticsearch

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3.1.2 Pulling a Mirror from a Remote Location

➜ ~ Docker Pull ElasticSearch :7.4.0

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3.1.3 Starting a Mirror

➜ ~ docker run -d --name myes -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" ElasticSearch :7.4.0

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3.1.4 access Elasticsearch

http://localhost:9200/

{

  "name" : "0222e17f062d".

  "cluster_name" : "docker-cluster".

  "cluster_uuid" : "OtL-k7FpR4ylPVsiKcZIkA".

  "version" : {

    "number" : "7.4.0".

    "build_flavor" : "default".

    "build_type" : "docker".

    "build_hash" : "22e1767283e61a198cb4db791ea66e3f11ab9910".

    "build_date" : "The 2019-09-27 T08:36:48. 569419 z".

    "build_snapshot" : false.

    "lucene_version" : "8.2.0".

    "minimum_wire_compatibility_version" : "6.8.0".

    "minimum_index_compatibility_version" : "6.0.0 - beta1"

  },

  "tagline" : "You Know, for Search"

}

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When you see the data returned above, congratulations on the successful es installation.

3.2 Elasticsearch Is Properly Installed

3.2.1 Downloading the installation package

Linux:

➜ ~ curl - L - O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.4.1-linux-x86_64.tar.gz

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MacOS:

➜ ~ wget HTTP: / / https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.4.1-darwin-x86_64.tar.gz

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3.2.2 Decompressing the installation package

Linux:

➜ ~ tar-xvf ElasticSearch-7.4.1-linux-x86_64.tar.gz

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macOS:

➜ ~ tar-xvf ElasticSearch-7.4.1 - Darwin x86_64.tar.gz

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3.2.3 run

Linux and macOS:

➜ ~ CD elasticsearch - 7.4.1 / bin

➜ ~. / elasticsearch

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3.3 access Elasticsearch

http://localhost:9200/

4. Add, delete, change, and check battles for Elasticsearch

Elasticsearch (SpringBoot) Elasticsearch (Elasticsearch

4.1 Creating a Project

Create boot-example-elasticSearch module

4.2 Adding a Dependency

<dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>



        <dependency>

            <groupId>org.projectlombok</groupId>

            <artifactId>lombok</artifactId>

        </dependency>



        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

        </dependency>



        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>

        </dependency>

    </dependencies>

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4.3 Configuring the Elasticsearch Address

spring:

  elasticsearch:

    rest:

      uris: http://localhost:9200 # specify es address

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4.4 Creating a Document Entity Class

@Data

@Builder

@NoArgsConstructor

@AllArgsConstructor

@ToString

@Document(indexName = "goods", type = "_doc")

public class Goods implements Serializable {



    @Id

    private Long id;



    @Field

    private String name;



    @Field

    private String title;



    @Field

    private BigDecimal price;



    @Field

    private String publishDate;

}

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You need to use the @document annotation to specify the index and Document type so that you don’t need to specify the index and type when manipulating Document data. Use the @ID annotation to indicate the Id of the document, and the @field annotation to indicate other attributes of the document

4.5 injection ElasticsearchRestTemplate

As usual with other middleware such as Redis and rabbitMQ, you need to inject the appropriate xxxxTemplate

@Autowired

private ElasticsearchRestTemplate elasticsearchRestTemplate;

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4.6 Adding Document Data

@Test

public void insert(a) {

    Goods goods = Goods.builder()

        .id(10006L)

        .name("Test goods")

        .title("I am a test goods, shot not delivery, please be careful!")

        .price(new BigDecimal(9999999))

        .publishDate("2019-11-06")

        .build();

    / * *

* index is used to add or modify the entire document

* The document does not exist, perform the new operation

* The document exists, perform the modification operation

* Here you only need to set the index object, the underlying code from the index object@DocumentGet the index, type, and document ID from the annotation

* /

    elasticsearchRestTemplate.index(new IndexQueryBuilder().withObject(goods).build());

    log.info("index document finish");

}

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4.7 Adding Document Data in Batches

@Test

public void batchInsert(a) {

    List<Goods> goodsList = buildGoodsList();

    List<IndexQuery> indexQueryList = new ArrayList<>();

    for (int i = 0, len = goodsList.size(); i < len; i++) {

        indexQueryList.add(new IndexQueryBuilder()

                           .withObject(goodsList.get(i)).build());

    }

    // Use the bulk method to bulk index documents

    elasticsearchRestTemplate.bulkIndex(indexQueryList);

    log.info("batch index document finish");

}

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4.8 Modifying Document Data

@Test

public void update(a) {

    Goods goods = Goods.builder()

        .id(10001L)

        .name("AppleiPhone 11 update")

        .title(Apple iPhone 11 (A2223) 64GB Black China Unicom 4G Mobile Phone Dual Sim Card Dual Waiting update)

        .price(new BigDecimal(6666))

        .publishDate("2019-12-12")

        .build();

    IndexQuery indexQuery = new IndexQueryBuilder()

        .withObject(goods)

        .build();

    / * *

* Use the index method to update the entire document

* If a field is null and updated to ES, it will not exist in the ES document

         * {

         *           "_class" : "com.boot.example.Goods",

         *           "id" : 10006,

         *           "name" : "AppleiPhone 11 update",

* "Title" : "Apple iPhone 11 (A2223) 64GB Black Mobile Unicom 4G Mobile Dual sim dual waiting update"

*}

* /

    elasticsearchRestTemplate.index(indexQuery);

    log.info("update document");

}

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4.9 Modifying Some Data in the Document

@Test

public void partialUpdate(a) {

    // Build the fields to be updated

    Map<String, Object> map = new HashMap<>();

    map.put("price".new BigDecimal(6666));

    map.put("publishDate"."2019-09-08");

    UpdateQuery updateQuery = new UpdateQueryBuilder()

        .withId("10001")

        .withClass(Goods.class)

        .withUpdateRequest(new UpdateRequest().doc(map))

        .build();

    // Update part of the document

    elasticsearchRestTemplate.update(updateQuery);

    log.info("partial update document");

}

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4.10 Querying Data of a Single Document

@Test

public void getById(a) {

    GetQuery getQuery = new GetQuery();

    getQuery.setId("10001");

    Goods goods = elasticsearchRestTemplate.queryForObject(getQuery, Goods.class);

    log.info("Get document by ID result: {}", goods);

}

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4.11 Querying Document List Data

@Test

public void list(a) {

    / * *

* Use match to search

         * GET /goods/_search

         * {

         *   "query": {

         *     "match": {

         *       "title": "apple"

*}

*}

*}

* /

    NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()

        .withQuery(new MatchQueryBuilder("title"."apple"))

        .withSort(new FieldSortBuilder("publishDate").order(SortOrder.DESC))

        .build();

    List<Goods> goodsList = elasticsearchRestTemplate.queryForList(nativeSearchQuery, Goods.class);

    log.info("List document size: {}, result: {}", goodsList.size(), goodsList);

}

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4.12 Querying Document List Data using Multiple Criteria

@Test

public void listByMultiCondition(a) {

    NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()

        .withQuery(new BoolQueryBuilder()

                   .must(new MatchQueryBuilder("title"."apple"))

                   .must(new RangeQueryBuilder("price").from(BigDecimal.ZERO).to(new BigDecimal(12800)))

                  )

        .build();

    List<Goods> goodsList = elasticsearchRestTemplate.queryForList(nativeSearchQuery, Goods.class);

    log.info("List document size: {}, result: {}", goodsList.size(), goodsList);

}

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4.13 Querying Document Data in Pages

@Test

public void page(a) {

    QueryBuilder queryBuilder = new MatchQueryBuilder("title"."apple");

    NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()

        .withQuery(queryBuilder)

        .withPageable(PageRequest.of(0.10))

        .build();

    / * *

* To view detailed request response logs, set the following parameters in the configuration file:

         * logging:

         *   level:

         *     tracer: trace

         *

[/O dispatcher 1] Dispatcher: [/O dispatcher 2] dispatcher: curl -iX POST 'http://localhost:9200/goods/_doc/_search? rest_total_hits_as_int=true&typed_keys=true&ignore_unavailable=false&expand_wildcards=open&allow_no_indices=true&ignore_ throttled=true&search_type=dfs_query_then_fetch&batched_reduce_size=512' -d '{"from":0,"size":10,"query":{"match":{"title":{"query":"apple","operator":"OR","prefix_length":0,"max_expansions":50,"f uzzy_transpositions":true,"lenient":false,"zero_terms_query":"NONE","auto_generate_synonyms_phrase_query":true,"boost":1 .0}}},"version":true}'

         *     # HTTP/1.1 200 OK

* # Warning: Elasticsearch 7.4.0-299-22 e1767283e61a198cb4db791ea66e3f11ab9910 "[types removal] Specifying the types in the search requests is  deprecated."

         *     # content-type: application/json; charset=UTF-8

         *     # content-length: 730

         *     #

* # {"took":0,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":2,"max_score":0. 76022595, "hits" : [{" _index ":" goods ", "_type" : "_doc", "_id" : "10001", "_version" : 2, "_score" : 0.76022595, "_source" : {" _class ":" co M.boot.example.Goods"," ID ":10001,"name":"AppleiPhone 11"," Title ":"AppleiPhone 11 (A2223) 64GB Black Mobile Unicom 4G mobile phone Double card double stay ", "price" : 6666, "publishDate" : "2019-09-08"}}, {" _index ":" goods ", "_type" : "_doc", "_id" : "10002", "_version" : 1, "_score" : 0.7 3438257,"_source":{"_class":"com.boot.example.Goods","id":10002,"name":"AppleMNYH2CH/A","title":"Apple MacBook 12 | Core MNYH2CH/A","price":12800.0,"publishDate":"2018-09-11"}}]}

* /

    Page<Goods> page = elasticsearchRestTemplate.queryForPage(nativeSearchQuery, Goods.class);

    List<Goods> goodsList = page.getContent();

    log.info("Document size: {}, result: {}", goodsList.size(), goodsList);

}

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4.14 Deleting a Document

@Test

public void delete(a) {

    // Delete the document

    elasticsearchRestTemplate.delete(Goods.class, "10001");

}

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5.Elasticsearch aggregation combat

5.1 Collecting Documents

@Test

public void count(a) {

    SearchQuery searchQuery = new NativeSearchQueryBuilder().build();

    Long count = elasticsearchRestTemplate.count(searchQuery, Goods.class);

    log.info("Goods count: {}", count);

}

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5.2 Average Value

@Test

public void avgPrice(a) {

    SearchQuery searchQuery = new NativeSearchQueryBuilder()

        .addAggregation(AggregationBuilders.avg("avg_price").field("price"))

        .withIndices("goods")

        .build();

    double avgPrice = elasticsearchRestTemplate.query(searchQuery, response -> {

        Avg avg = response.getAggregations().get("avg_price");

        return avg.getValue();

    });

    log.info("Avg_price: {}", avgPrice);

}

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5.3 Finding the Maximum value

@Test

public void maxPrice(a) {

    SearchQuery searchQuery = new NativeSearchQueryBuilder()

        .addAggregation(AggregationBuilders.max("max_price").field("price"))

        .withIndices("goods")

        .build();

    double maxPrice = elasticsearchRestTemplate.query(searchQuery, response -> {

        Max max = response.getAggregations().get("max_price");

        return max.getValue();

    });

    log.info("Max_price: {}", maxPrice);

}

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6. ElasticsearchRestTemplate API

Elasticsearch with SpringBoot

7.1 ElasticsearchDataConfiguration

Statement of our most important ElasticsearchRestTemplate ElasticsearchRestTemplate need RestHighLevelClient

7.2 RestClientConfigurations

Declare RestHighLevelClient, RestHighLevelClient requires RestClientBuilder

Declare the RestClientBuilder. The RestClientBuilder is built by RestClient. The hosts used by the build are obtained from the URIS property of RestClientProperties, which is specified in the configuration file

spring:

  elasticsearch:

    rest:

      uris: http://localhost:9200 # specify es address

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Through this article you not only learn how to integrate SpringBoot and Elasticsearch, also can be used to ElasticsearchRestTemplate document to add, delete, change, check operation, finally you also know the Elasticsearch principle of automatic configuration, I hope you found this knowledge helpful.

8. Project address

boot-example