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package org.nlpcn.es4sql.query;
import com.alibaba.druid.support.json.JSONUtils;
import org.elasticsearch.action.search.SearchAction;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.elasticsearch.action.search.SearchScrollAction;
import org.elasticsearch.action.search.SearchScrollRequestBuilder;
import org.elasticsearch.action.search.SearchType;
import org.elasticsearch.client.Client;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.script.Script;
import org.elasticsearch.script.ScriptType;
import org.elasticsearch.search.sort.FieldSortBuilder;
import org.elasticsearch.search.sort.NestedSortBuilder;
import org.elasticsearch.search.sort.ScriptSortBuilder;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.nlpcn.es4sql.domain.Field;
import org.nlpcn.es4sql.domain.KVValue;
import org.nlpcn.es4sql.domain.MethodField;
import org.nlpcn.es4sql.domain.Order;
import org.nlpcn.es4sql.domain.Select;
import org.nlpcn.es4sql.domain.Where;
import org.nlpcn.es4sql.domain.hints.Hint;
import org.nlpcn.es4sql.domain.hints.HintType;
import org.nlpcn.es4sql.exception.SqlParseException;
import org.nlpcn.es4sql.query.maker.QueryMaker;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
/**
* Transform SQL query to standard Elasticsearch search query
*/
public class DefaultQueryAction extends QueryAction {
private final Select select;
private SearchRequestBuilder request;
private List fieldNames = new LinkedList<>();
public DefaultQueryAction(Client client, Select select) {
super(client, select);
this.select = select;
}
/**
* zhongshu-comment 只被调用了一次，就在AggregationQueryAction类中
* @param request
* @throws SqlParseException
*/
public void intialize(SearchRequestBuilder request) throws SqlParseException {
this.request = request;
}
//zhongshu-comment 将sql字符串解析后的java对象，转换为es的查询请求对象
@Override
public SqlElasticSearchRequestBuilder explain() throws SqlParseException {
Hint scrollHint = null;
for (Hint hint : select.getHints()) {
if (hint.getType() == HintType.USE_SCROLL) {
scrollHint = hint;
break;
}
}
if (scrollHint != null && scrollHint.getParams()[0] instanceof String) {
return new SqlElasticSearchRequestBuilder(new SearchScrollRequestBuilder(client, SearchScrollAction.INSTANCE, (String) scrollHint.getParams()[0]).setScroll(new TimeValue((Integer) scrollHint.getParams()[1])));
}
/*
zhongshu-comment 6.1.1.5这个版本和elastic6.1.1这个分支用的是这一行代码
但是在本地调试时我的client没有实例化，并没有去连es，所以这行代码会报空指针
那就将这行注释掉吧，以后就用下面那行
*/
// this.request = client.prepareSearch();
/*
zhongshu-comment 6.2.4.1这个版本和master_zhongshu_dev_01用的是这一行代码，虽然client为null，但是下面这行代码并不会报空指针
为了在本地调试、执行下文的那些代码获得es的dsl，所以就使用这行代码，暂时将上面哪一行注释掉，上线的时候记得替换掉
变量request是es搜索请求对象，调用的是es的api，SearchRequestBuilder是es的原生api
*/
this.request = new SearchRequestBuilder(client, SearchAction.INSTANCE);
setIndicesAndTypes();
//zhongshu-comment 将Select对象中封装的sql token信息转换并传到成员变量es搜索请求对象request中
setFields(select.getFields());
setWhere(select.getWhere());
setSorts(select.getOrderBys());
setLimit(select.getOffset(), select.getRowCount());
//
if (scrollHint != null) {
if (!select.isOrderdSelect())
request.addSort(FieldSortBuilder.DOC_FIELD_NAME, SortOrder.ASC);
request.setSize((Integer) scrollHint.getParams()[0]).setScroll(new TimeValue((Integer) scrollHint.getParams()[1]));
} else {
request.setSearchType(SearchType.DFS_QUERY_THEN_FETCH);
}
updateRequestWithIndexAndRoutingOptions(select, request);
updateRequestWithHighlight(select, request);
updateRequestWithCollapse(select, request);
updateRequestWithPostFilter(select, request);
updateRequestWithStats(select, request);
updateRequestWithPreference(select, request);
updateRequestWithTrackTotalHits(select, request);
updateRequestWithTimeout(select, request);
updateRequestWithIndicesOptions(select, request);
updateRequestWithMinScore(select, request);
SqlElasticSearchRequestBuilder sqlElasticRequestBuilder = new SqlElasticSearchRequestBuilder(request);
return sqlElasticRequestBuilder;
}
/**
* Set indices and types to the search request.
*/
private void setIndicesAndTypes() {
request.setIndices(query.getIndexArr());
String[] typeArr = query.getTypeArr();
if (typeArr != null) {
request.setTypes(typeArr);
}
}
/**
* Set source filtering on a search request.
* zhongshu-comment 即es dsl中的include和exclude
* @param fields
* list of fields to source filter.
*/
public void setFields(List fields) throws SqlParseException {
/*
zhongshu-comment select * from tbl_a;
select * 这种sql语句的select.getFields().size()为0
*/
if (select.getFields().size() > 0) {
ArrayList includeFields = new ArrayList();
ArrayList excludeFields = new ArrayList();
for (Field field : fields) {
if (field instanceof MethodField) { //zhongshu-comment MethodField是Field的子类，而且Field也就只有MethodField这一个子类了
MethodField method = (MethodField) field;
if (method.getName().toLowerCase().equals("script")) {
/*
zhongshu-comment scripted_field only allows script(name,script) or script(name,lang,script)
script类型的MethodField是不会加到include和exclude中的
*/
handleScriptField(method);
} else if (method.getName().equalsIgnoreCase("include")) {
String f;
for (KVValue kvValue : method.getParams()) {
//zhongshu-comment select a,b,c 中的a、b、c字段add到includeFields中
f = kvValue.value.toString();
fieldNames.add(f);
includeFields.add(f);
}
} else if (method.getName().equalsIgnoreCase("exclude")) {
for (KVValue kvValue : method.getParams()) {
excludeFields.add(kvValue.value.toString()) ;
}
} else if (method.getName().equalsIgnoreCase("docvalue")) {
handleDocvalueField(method);
}
} else if (field != null) {
fieldNames.add(field.getName());
includeFields.add(field.getName());
}
}
request.setFetchSource(
includeFields.toArray(new String[includeFields.size()]),
excludeFields.toArray(new String[excludeFields.size()])
);
}
}
/**
* zhongshu-comment scripted_field only allows script(name,script) or script(name,lang,script)
* @param method
* @throws SqlParseException
*/
private void handleScriptField(MethodField method) throws SqlParseException {
List params = method.getParams();
if (params.size() == 2) {
String f = params.get(0).value.toString();
fieldNames.add(f);
request.addScriptField(f, new Script(params.get(1).value.toString()));
} else if (params.size() == 3) {
String f = params.get(0).value.toString();
fieldNames.add(f);
request.addScriptField(f,
new Script(
ScriptType.INLINE,
params.get(1).value.toString(),
params.get(2).value.toString(),
Collections.emptyMap()
)
);
} else {
throw new SqlParseException("scripted_field only allows script(name,script) or script(name,lang,script)");
}
}
private void handleDocvalueField(MethodField method) throws SqlParseException {
List params = method.getParams();
if (params.size() == 1) {
String f = params.get(0).value.toString();
fieldNames.add(f);
request.addDocValueField(f);
} else if (params.size() == 2) {
String f = params.get(0).value.toString();
fieldNames.add(f);
request.addDocValueField(f, params.get(1).value.toString());
} else {
throw new SqlParseException("docvalue_fields only allows docvalue(field) or docvalue(field,format)");
}
}
/**
* Create filters or queries based on the Where clause.
*
* @param where
* the 'WHERE' part of the SQL query.
* @throws SqlParseException
*/
private void setWhere(Where where) throws SqlParseException {
if (where != null) {
BoolQueryBuilder boolQuery = QueryMaker.explan(where,this.select.isQuery);
request.setQuery(boolQuery);
}
}
/**
* Add sorts to the elasticsearch query based on the 'ORDER BY' clause.
*
* @param orderBys
* list of Order object
*/
private void setSorts(List orderBys) {
for (Order order : orderBys) {
if (order.getNestedPath() != null) {
request.addSort(SortBuilders.fieldSort(order.getName()).order(SortOrder.valueOf(order.getType())).setNestedSort(new NestedSortBuilder(order.getNestedPath())));
} else if (order.getName().contains("script(")) { //zhongshu-comment 该分支是我后来加的，用于兼容order by case when那种情况
String scriptStr = order.getName().substring("script(".length(), order.getName().length() - 1);
Script script = new Script(scriptStr);
ScriptSortBuilder scriptSortBuilder = SortBuilders.scriptSort(script, order.getScriptSortType());
scriptSortBuilder = scriptSortBuilder.order(SortOrder.valueOf(order.getType()));
request.addSort(scriptSortBuilder);
} else {
request.addSort(
order.getName(),
SortOrder.valueOf(order.getType()));
}
}
}
/**
* Add from and size to the ES query based on the 'LIMIT' clause
*
* @param from
* starts from document at position from
* @param size
* number of documents to return.
*/
private void setLimit(int from, int size) {
request.setFrom(from);
if (size > -1) {
request.setSize(size);
}
}
public SearchRequestBuilder getRequestBuilder() {
return request;
}
public List getFieldNames() {
return fieldNames;
}
}
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