說明：Es提供了多種不同的客戶端：
-
TransportClient：傳統客戶端，預計8.0版本會下掉
-
RestClient：官方推薦，它又包括兩種
- Java Low Level REST Client
- Java High Level REST Client
ES在6.0後提供Java High Level Rest Client，這兩種官方更推薦使用High Level
接下來我們開始使用Java客戶端進行操作。
環境搭建
- 引入依賴
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.3.0</version>
<exclusions>
<exclusion>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>7.3.0</version>
</dependency>
- 配置Es連接信息
@Configuration
public class ElasticsearchConfig {
private String hosts = "192.168.56.115:9200";
@Bean
public RestHighLevelClient restHighLevelClient(){
String[] hostArray= new String[]{hosts};
HttpHost[] httpHosts=new HttpHost[hostArray.length];
for (int i=0;i<hostArray.length;i++){
String host = hostArray[i];
String[] split = host.split(":");
httpHosts[i]=new HttpHost(split[0],Integer.valueOf(split[1]),"http");
}
return new RestHighLevelClient(RestClient.builder(httpHosts));
}
}
ES API操作
- 創建索引
@Test
public void createIndex() throws IOException {
CreateIndexRequest createIndexRequest=new CreateIndexRequest("es_java");
//設置參數
createIndexRequest.settings(Settings.builder().put("number_of_shards","1").put("number_of_replicas","0"));
XContentBuilder xContentBuilder=XContentFactory.jsonBuilder()
.startObject()
.field("properties")
.startObject()
.field("description")
.startObject().field("type","text")
.field("analyzer","ik_max_word")
.endObject()
.field("name").startObject()
.field("type","keyword")
.endObject()
.field("pic").startObject()
.field("type","text")
.field("index",false)
.endObject()
.field("studymodel")
.startObject()
.field("type","keyword")
.endObject()
.endObject().endObject();
createIndexRequest.mapping(xContentBuilder);
//操作索引的客戶端
IndicesClient indices = client.indices();
CreateIndexResponse createIndexResponse = indices.create(createIndexRequest, RequestOptions.DEFAULT);
boolean acknowledged = createIndexResponse.isAcknowledged();
System.out.println("創建結果："+acknowledged);
}
通過json的方式創建索引
@Test
public void createIndexByJson() throws IOException {
CreateIndexRequest createIndexRequest=new CreateIndexRequest("es_java");
//設置參數
createIndexRequest.settings(Settings.builder().put("number_of_shards","1").put("number_of_replicas","0"));
createIndexRequest.mapping("{\n" +
" \"properties\": {\n" +
" \"description\": {\n" +
" \"type\": \"text\",\n" +
" \"analyzer\": \"ik_max_word\"\n" +
" },\n" +
" \"name\": {\n" +
" \"type\": \"keyword\"\n" +
" },\n" +
" \"pic\": {\n" +
" \"type\": \"text\",\n" +
" \"index\": false\n" +
" },\n" +
" \"studymodel\": {\n" +
" \"type\": \"keyword\"\n" +
" }\n" +
" }\n" +
" }.",XContentType.JSON);
//操作索引的客戶端
IndicesClient indices = client.indices();
CreateIndexResponse createIndexResponse = indices.create(createIndexRequest, RequestOptions.DEFAULT);
boolean acknowledged = createIndexResponse.isAcknowledged();
System.out.println("創建結果："+acknowledged);
}
- 刪除索引
@Test
public void deleteIndex() throws IOException {
DeleteIndexRequest deleteIndexRequest=new DeleteIndexRequest("es_java");
IndicesClient indices = client.indices();
AcknowledgedResponse acknowledgedResponse = indices.delete(deleteIndexRequest, RequestOptions.DEFAULT);
System.out.println(acknowledgedResponse.isAcknowledged());
}
- 添加文檔
@Test
public void testAddDoc() throws IOException {
IndexRequest indexRequest=new IndexRequest("es_java","_doc");
indexRequest.id("1");
Map<String,Object> jsonMap=new HashMap<>();
jsonMap.put("name","spring cloud實戰");
jsonMap.put("description","本課程主要從四個章節進行講解： 1.微服務架構入門\n" +
"2.spring cloud 基礎入門 3.實戰Spring Boot 4.註冊中心eureka");
jsonMap.put("studymodel","20001");
jsonMap.put("name","spring cloud實戰");
jsonMap.put("pic","ttt.jpg");
indexRequest.source(jsonMap);
IndexResponse indexResponse = client.index(indexRequest, RequestOptions.DEFAULT);
System.out.println(indexResponse.getResult());
}
- 查詢文檔
@Test
public void testGetDoc() throws IOException {
GetRequest getRequest=new GetRequest("es_java","1");
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();
System.out.println(sourceAsMap);
}
- match搜索
@Test
public void testSearchAll() throws IOException {
SearchRequest searchRequest=new SearchRequest("es_java");
SearchSourceBuilder searchSourceBuilder=new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchAllQuery());
seachDoc(searchRequest, searchSourceBuilder);
}
private void seachDoc(SearchRequest searchRequest, SearchSourceBuilder searchSourceBuilder) throws IOException {
//第一個參數代表結果集包含什麼字段，第二個參數代表結果集不包括哪些字段
searchSourceBuilder.fetchSource(new String[]{"name","studymodel","description","pic"},new String[]{});
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
//搜索結果
SearchHits hits = searchResponse.getHits();
//匹配的記錄數
TotalHits totalHits = hits.getTotalHits();
for (SearchHit hit:hits){
String id = hit.getId();
//源文檔內容
Map<String, Object> sourceAsMap = hit.getSourceAsMap();
System.out.println("文檔的id："+id);
System.out.println(sourceAsMap);
}
}
- term搜索
@Test
public void testTermQuery() throws IOException {
SearchRequest searchRequest=new SearchRequest("es_java");
SearchSourceBuilder searchSourceBuilder=new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.termQuery("name","spring"));
seachDoc(searchRequest,searchSourceBuilder);
}
- 分頁搜索及排序
@Test
public void testSearchPage() throws IOException {
SearchRequest searchRequest=new SearchRequest("es_java");
SearchSourceBuilder searchSourceBuilder=new SearchSourceBuilder();
searchSourceBuilder.from(0);
searchSourceBuilder.size(2);
searchSourceBuilder.sort("name",SortOrder.DESC);
searchSourceBuilder.query(QueryBuilders.matchAllQuery());
seachDoc(searchRequest,searchSourceBuilder);
}