Elasticsearch入门学习:使用javaAPI学习ES
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一、Maven依赖
<!--刚开始少这个包创建索引失败 Validation Failed: 1: type is missing; 官方文档并没有给这个提示-->
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
<version>7.1.0</version>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>7.1.0</version>
</dependency>
二、开始之前的准备
/**
* 连接ES
* @return
*/
public RestHighLevelClient start() {
RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
RestClient.builder(
new HttpHost("192.168.100.151", 9201, "http"),
new HttpHost("192.168.100.151", 9202, "http"),
new HttpHost("192.168.100.151", 9203, "http")));
return restHighLevelClient;
}
/**
* 操作所用到的实体类
*/
@Data
class Article{
private long id;
private String title;
public Article(long id, String title) {
this.id = id;
this.title = title;
}
}
三、关于索引的操作
- 新增索引
public void createIndex(RestHighLevelClient client) {
//索引名称
CreateIndexRequest request = new CreateIndexRequest("hello");
//分片副本
request.settings(Settings.builder().put("index.number_of_shards", 5)
.put("index.number_of_replicas", 1));
//内容
Map <String,Object> id = new HashMap <>();
id.put("type","text");
id.put("store",true);
Map <String,Object> title = new HashMap <>();
title.put("type","text");
title.put("store",true);
title.put("index",true);
title.put("analyzer", "standard");
Map <String,Object> properties = new HashMap <>();
properties.put("id",id);
properties.put("title",title);
Map <String,Object> mapping = new HashMap <>();
mapping.put("properties",properties);
request.mapping(mapping);
try {
CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);
System.out.println(response.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
- 查询指定索引
public void getIndex(RestHighLevelClient client) throws IOException {
//索引名称
GetIndexRequest request = new GetIndexRequest("hello");
try {
boolean exists = client.indices().exists(request, RequestOptions.DEFAULT);
System.out.println(exists);
} catch (IOException e) {
e.printStackTrace();
}
}
- 删除索引
public void delIndex(RestHighLevelClient client){
DeleteIndexRequest request = new DeleteIndexRequest("hello");
try {
AcknowledgedResponse delete = client.indices().delete(request, RequestOptions.DEFAULT);
System.out.println(delete.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
四、关于文档的操作
- 创建文档
public void createDocument(RestHighLevelClient client){
//索引名称
IndexRequest indexRequest = new IndexRequest("hello");
ObjectMapper mapper = new ObjectMapper();
Article article = new Article(3L, "web前端");
byte[] json = new byte[0];
try {
json = mapper.writeValueAsBytes(article);
//可以设置文章ID
indexRequest.id("5");
indexRequest.source(json, XContentType.JSON);
IndexResponse index = client.index(indexRequest, RequestOptions.DEFAULT);
} catch (Exception e) {
e.printStackTrace();
}
}
- 根据文档ID查询文档
public void getDocument(RestHighLevelClient client){
GetRequest getRequest = new GetRequest("hello", "1");
GetResponse documentFields = null;
try {
documentFields = client.get(getRequest, RequestOptions.DEFAULT);
System.out.println(documentFields.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
- 更新文档
public void updateDocument(RestHighLevelClient client){
UpdateRequest updateRequest = new UpdateRequest("hello", "1");
Article article = new Article(2L, "java入门到放弃");
ObjectMapper mapper = new ObjectMapper();
byte[] json = new byte[0];
try {
json = mapper.writeValueAsBytes(article);
IndexRequest indexRequest = new IndexRequest("hello");
indexRequest.source(json, XContentType.JSON);
updateRequest.doc(indexRequest);
UpdateResponse updateResponse = client.update(
updateRequest, RequestOptions.DEFAULT);
System.out.println(updateResponse);
} catch (Exception e) {
e.printStackTrace();
}
}
- 删除文档
public void delDocument(RestHighLevelClient client){
DeleteRequest request = new DeleteRequest("hello", "1");
try {
DeleteResponse deleteResponse = client.delete(
request, RequestOptions.DEFAULT);
System.out.println(deleteResponse);
} catch (IOException e) {
e.printStackTrace();
}
}
- 查询文档
public void searchDocument(RestHighLevelClient client){
SearchRequest searchRequest = new SearchRequest();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchAllQuery());
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = null;
try {
searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
System.out.println(searchResponse.toString());
} catch (IOException e) {
e.printStackTrace();
}
}
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