DSL搜索
DSL(Domain Specific Language)是ES提出的基于json的搜索方式，在搜索时传入特定的json格式的数据来完成不同的搜索需求，DSL比URI搜索方式功能强大，在项目中建议使用DSL方式来完成搜索。
语法：
GET /index_name/type_name/_search
{
"commond":{
"parameter_name" : "parameter_value"
}
}
match_all查询
api
GET /java01/course/_search
{
"query" : {
"match_all" : {}
}
}
搭建工程
pom
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.2.RELEASE</version>
</parent>
<groupId>com.bjpowernode</groupId>
<artifactId>springboot_elasticsearch</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
<!-- 修改elasticsearch的版本 -->
<elasticsearch.version>6.2.3</elasticsearch.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>${elasticsearch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
</dependencies>
</project>
application.yml
spring:
elasticsearch:
rest:
uris:
- http://192.168.226.206:9200 #elasticsearch地址
App启动类
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class ElasticsearchApp {
public static void main(String[] args) {
SpringApplication.run(ElasticsearchApp.class, args);
}
}
java client
import com.bjpowernode.ElasticsearchApp;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.io.IOException;
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticsearchApp.class)
public class IndexReaderTestA {
@Autowired
private RestHighLevelClient restHighLevelClient;
private SearchRequest searchRequest;
private SearchResponse searchResponse;
@Before
public void init(){
//创建search请求对象
searchRequest = new SearchRequest();
searchRequest.indices("java01");
searchRequest.types("course");
}
@Test
public void testMatchAll() throws IOException {
//创建 参数构造器
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchAllQuery());
//设置请求参数
searchRequest.source(searchSourceBuilder);
//调用search方法
searchResponse = restHighLevelClient.search(searchRequest);
}
@After
public void show(){
//遍历查询结果
SearchHits searchHits = searchResponse.getHits();
long totalHits = searchHits.getTotalHits();
System.out.println("共搜索到"+totalHits+"条文档");
SearchHit[] hits = searchHits.getHits();
for (SearchHit hit : hits) {
System.out.println(hit.getSourceAsString());
}
}
}
分页查询
api
GET /java01/course/_search
{
"query": {
"match_all": {}
},
"from": 1,
"size": 3,
"sort": [
{
"price": "asc"
}
]
}
java client
//分页查询
@Test
public void testPage() throws IOException {
//查询条件构造器
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchAllQuery());
searchSourceBuilder.from(1);
searchSourceBuilder.size(20);
searchSourceBuilder.sort("price", SortOrder.DESC);
searchResponse = restHighLevelClient.search(searchRequest);
}
match查询
match Query即全文检索，它的搜索方式是先将搜索字符串分词，再使用各各词条从索引中搜索。
api
query：搜索的关键字
operator：or 表示 只要有一个词在文档中出现则就符合条件，and表示每个词都在文档中出现则才符合条件。
GET /java01/course/_search
{
"query": {
"match": {
"name": {
"query": "spring开发"
}
}
}
}
operator
GET /java01/course/_search
{
"query": {
"match": {
"name": {
"query": "spring开发",
"operator":"and"
}
}
}
}
上边的搜索的执行过程是：
1、将“spring开发”分词，分为spring、开发两个词
2、再使用spring和开发两个词去匹配索引中搜索。
3、由于设置了operator为and，必须匹配两个词成功时才返回该文档。
java client
@Test
public void testMarchQuery() throws IOException {
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchQuery("name","spring开发")
.operator(Operator.AND));
//设置所搜源
searchRequest.source(searchSourceBuilder);
//执行
searchResponse = restHighLevelClient.search(searchRequest);
}
multi_match查询
matchQuery是在一个field中去匹配，multiQuery是拿关键字去多个Field中匹配。
api
关键字 “开发”去匹配name 和description字段
GET /java01/course/_search
{
"query": {
"multi_match": {
"query": "开发",
"fields": ["name","description"]
}
}
}
此搜索操作适合构建复杂查询条件，生产环境常用。
java client
@Test
public void testMultiMatchQuery() throws IOException {
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.multiMatchQuery("开发", "name", "description"));
//设置搜索源
searchRequest.source(searchSourceBuilder);
//执行
searchResponse = restHighLevelClient.search(searchRequest);
}
bool查询
布尔查询对应于Lucene的BooleanQuery查询，实现将多个查询组合起来。
参数：
must：表示必须，多个查询条件必须都满足。（通常使用must）
should：表示或者，多个查询条件只要有一个满足即可。
must_not：表示非。
api
查询name包括“开发”并且价格区间是1-100的文档
GET /java01/course/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"name": "开发"
}
},
{
"range": {
"price": {
"gte": 50,
"lte": 100
}
}
}
]
}
}
}
java client
@Test
public void testBooleanMarch() throws IOException {
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
//json条件
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
boolQueryBuilder.must(QueryBuilders.matchQuery("name","开发"));
boolQueryBuilder.must(QueryBuilders.rangeQuery("price").gte("50").lte(100));
searchSourceBuilder.query(boolQueryBuilder);
searchRequest.source(searchSourceBuilder);
searchResponse = restHighLevelClient.search(searchRequest);
}
filter查询
过滤查询。此操作实际上就是 query DSL 的补充语法。过滤的时候，不进行任何的匹配分数计算，相对于 query 来说，filter 相对效率较高。Query 要计算搜索匹配相关度分数。Query更加适合复杂的条件搜索。
api
使用bool查询，搜索 name中包含 "开发"的数据，且price在 10~100 之间
不使用 filter， name和price需要计算相关度分数：
GET /java01/course/_search
{
"query": {
"bool" : {
"must":[
{
"match": {
"name": "开发"
}
},
{
"range": { # 范围，字段的数据必须满足某范围才有结果。
"price": {
"gte": 10, # 比较符号 lt gt lte gte
"lte": 100
}
}
}
]
}
}
}
使用 filter， price不需要计算相关度分数：
GET /java01/course/_search
{
"query": {
"bool": {
"must": [
{
"match": {
"name": "开发"
}
}
],
"filter": { # 过滤，在已有的搜索结果中进行过滤，满足条件的返回。
"range": {
"price": {
"gte": 1,
"lte": 100
}
}
}
}
}
}
java client
@Test
public void testFilterQuery() throws IOException {
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
boolQueryBuilder.must(QueryBuilders.matchQuery("name", "开发"));
boolQueryBuilder.filter(QueryBuilders.rangeQuery("price").gte(10).lte(100));
searchSourceBuilder.query(boolQueryBuilder);
searchRequest.source(searchSourceBuilder);
searchResponse = restHighLevelClient.search(searchRequest);
}
highlight查询
高亮显示：高亮不是搜索条件，是显示逻辑，在搜索的时候，经常需要对搜索关键字实现高亮显示。
api
GET /java01/course/_search
{
"query": {
"match": {
"name": "开发"
}
},
"highlight": {
"pre_tags": ["<font color='red'>"],
"post_tags": ["</font>"],
"fields": {"name": {}}
}
}
java client
@Test
public void testHighLightQuery() throws IOException {
//查询条件构造器
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(QueryBuilders.matchQuery("name", "spring"));
//设置高亮
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.preTags("<font color='red'>");
highlightBuilder.postTags("</font>");
highlightBuilder.fields().add(new HighlightBuilder.Field("name"));
searchSourceBuilder.highlighter(highlightBuilder);
searchRequest.source(searchSourceBuilder);
searchResponse = restHighLevelClient.search(searchRequest);
}
@After
public void show() {
//遍历查询结果
SearchHits searchHits = searchResponse.getHits();
long totalHits = searchHits.getTotalHits();
System.out.println("共搜索到" + totalHits + "条文档");
SearchHit[] hits = searchHits.getHits();
for (SearchHit hit : hits) {
System.out.println(hit.getSourceAsString());
Map<String, HighlightField> map = hit.getHighlightFields();
if (map != null && map.size() > 0){
HighlightField name = map.get("name");
System.out.println(name.getFragments()[0].toString());
}
}
}
}
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