ES High Level REST Client API 查詢 聚合
1 準備數據
首先啓動好的ES6.8服務和Kibana服務
1.1 插入測試數據
假設有個部門組織的場景，部門有上級部門或者下級部門，像一顆樹那樣
| 字段 | 註釋 |
|---|---|
| code | 部門編號 |
| name | 部門名稱 |
| level | 層級 |
| path | 從祖先到自己的id路徑 |
| parentId | 父部門Id （這裏沒有id字段，因爲es自帶_id這個字段了） |
| status | 狀態 |
PUT /dept/_doc/1
{
"code": "dept_1",
"name": "部門1",
"level": 1,
"path": "1",
"parentId": "",
"status":1
}
PUT /dept/_doc/2
{
"code": "dept_2",
"name": "部門2",
"level": 1,
"path": "2",
"parentId": "",
"status":0
}
PUT /dept/_doc/3
{
"code": "dept_1_1",
"name": "部門1_1",
"level": 2,
"path": "1,3",
"parentId": "1",
"status":0
}
PUT /dept/_doc/4
{
"code": "dept_1_2",
"name": "部門1_2",
"level": 2,
"path": "1,4",
"parentId": "1",
"status":0
}
PUT /dept/_doc/5
{
"code": "dept_1_1_1",
"name": "部門1_1_1",
"level": 3,
"path": "1,3,5",
"parentId": "3",
"status":1
}
PUT /dept/_doc/6
{
"code": "dept_1_1_2",
"name": "部門1_1_2",
"level": 3,
"path": "1,3,6",
"parentId": "3",
"status":null
}
數據結果如下：
2 Maven引入ES
新建一個空的Maven結構項目，在pom.xml裏添加如下
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.8.4</version>
</dependency>
3 創建Client
public class EsRestUtils {
private static RestHighLevelClient client;
private static final String type = "_doc";
public static RestHighLevelClient getClient() {
if (client == null) {
client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("192.168.8.201", 9200, "http")));
}
return client;
}
}
4 查詢API
4.1 根據id查詢單條數據
用SQL描述就是
select * from dept where id = '1'
protected static Map<String, Object> getById(String index, String id) throws IOException {
getClient();
GetRequest getRequest = new GetRequest(index, type, id);
GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
if (getResponse.isExists()){
return getResponse.getSourceAsMap();
}
return null;
}
4.2 根據多個id查詢
用SQL描述就是
select * from dept where id in ("1", "2", "3")
protected static List<Map<String, Object>> getByIds(String index, List<String> ids) throws IOException {
getClient();
List<Map<String, Object>> results = new ArrayList<>();
MultiGetRequest request = new MultiGetRequest();
ids.stream().forEach(id -> {
request.add(new MultiGetRequest.Item(index, type, id));
});
MultiGetResponse response = client.mget(request, RequestOptions.DEFAULT);
GetResponse getResponse;
for (int i = 0; i < response.getResponses().length; i++) {
getResponse = response.getResponses()[i].getResponse();
if (getResponse.isExists()) {
results.add(getResponse.getSourceAsMap());
}
}
return results;
}
4.3 根據條件分頁查詢
用SQL描述就是
select * from dept where id in ("1", "2", "3") limt 2,10
protected static List<Map<String, Object>> getByWhere(String index, QueryBuilder queryBuilder, int pageNo, int pageSize) throws IOException {
getClient();
List<Map<String, Object>> results = new ArrayList<>();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(queryBuilder);
searchSourceBuilder.from(pageNo);
searchSourceBuilder.size(pageSize);
SearchRequest searchRequest = new SearchRequest(index).types(type);
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
SearchHits hits = searchResponse.getHits();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
results.add(hit.getSourceAsMap());
}
return results;
}
4.4 count
用SQL描述就是
select count(1) from dept where name like '部門%'
public static long count(QueryBuilder queryBuilder, String... indexs) throws IOException {
getClient();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(queryBuilder);
CountRequest countRequest = new CountRequest(indexs);
countRequest.source(searchSourceBuilder);
CountResponse countResponse = client.count(countRequest, RequestOptions.DEFAULT);
long count = countResponse.getCount();
return count;
}
4.5 max
用SQL描述就是
select max(level) from dept where name like '部門%'
public static Double getMax(QueryBuilder queryBuilder, String field, String... indexs) throws IOException {
getClient();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(queryBuilder);
searchSourceBuilder.size(0);
AggregationBuilder aggregationBuilder = AggregationBuilders.max("agg").field(field);
searchSourceBuilder.aggregation(aggregationBuilder);
SearchRequest searchRequest = new SearchRequest(indexs).types(type);
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
Max agg = searchResponse.getAggregations().get("agg");
return agg.getValue();
}
5 terms聚合
5.1 根據1個字段group by
用SQL描述就是
select level, count(id) from dept where name like '部門%' group by level
public static Map<String, Long> getTermsAgg(QueryBuilder queryBuilder, String field, String...
Map<String, Long> groupMap = new HashMap<>();
getClient();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(queryBuilder);
searchSourceBuilder.size(0);
AggregationBuilder aggregationBuilder = AggregationBuilders.terms("agg").field(field);
searchSourceBuilder.aggregation(aggregationBuilder);
SearchRequest searchRequest = new SearchRequest(indexs).types(type);
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
Terms terms = searchResponse.getAggregations().get("agg");
for (Terms.Bucket entry : terms.getBuckets()) {
groupMap.put(entry.getKey().toString(), entry.getDocCount());
}
return groupMap;
}
寫代碼測試
protected static void testGetTermsAgg(String index) {
QueryBuilder queryBuilder = QueryBuilders.wildcardQuery("name.keyword", "部門*");
try {
Map<String, Long> groupMap = EsRestUtils.getTermsAgg(queryBuilder, "level", index);
groupMap.forEach((key, value) -> System.out.println(key + " -> " + value.toString()));
} catch (IOException e) {
e.printStackTrace();
}
}
運行結果如下，左邊是level，右邊是個數
1 -> 2
2 -> 2
3 -> 2
5.2 根據多個字段group by
用SQL描述就是
select level, status, count(id) from dept where name like '部門%' group by level, status
public static Map<String, Map<String, Long>> getTermsAggTwoLevel(QueryBuilder queryBuilder, String field1, String field2, String... indexs) throws IOException {
Map<String, Map<String, Long>> groupMap = new HashMap<>();
getClient();
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
searchSourceBuilder.query(queryBuilder);
searchSourceBuilder.size(0);
AggregationBuilder agg1 = AggregationBuilders.terms("agg1").field(field1);
AggregationBuilder agg2 = AggregationBuilders.terms("agg2").field(field2);
agg1.subAggregation(agg2);
searchSourceBuilder.aggregation(agg1);
SearchRequest searchRequest = new SearchRequest(indexs).types(type);
searchRequest.source(searchSourceBuilder);
SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
Terms terms1 = searchResponse.getAggregations().get("agg1");
Terms terms2;
for (Terms.Bucket bucket1 : terms1.getBuckets()) {
terms2 = bucket1.getAggregations().get("agg2");
Map<String, Long> map2 = new HashMap<>();
for (Terms.Bucket bucket2 : terms2.getBuckets()) {
map2.put(bucket2.getKey().toString(), bucket2.getDocCount());
}
groupMap.put(bucket1.getKey().toString(), map2);
}
return groupMap;
}
寫代碼測試
protected static void testGetTermsAgg2(String index) {
QueryBuilder queryBuilder = QueryBuilders.wildcardQuery("name.keyword", "部門*");
try {
Map<String, Map<String, Long>> groupMap = EsRestUtils.getTermsAggTwoLevel(queryBuilder, "level", "status", index);
groupMap.forEach((key, value) -> System.out.println(key + " -> " + value.toString()));
} catch (IOException e) {
e.printStackTrace();
}
}
對於id=6的那條數據，status=null，就不會統計到，如果沒有status也不會統計到。
1 -> {0=1, 1=1}#leve=1的數據中，status=1的1條，status=0的1條
2 -> {0=2} #leve=2的數據中，status=0的2條
3 -> {1=1} #leve=3的數據中，status=1的1條
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