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How to convert for each loops into Java streams and lambda function?

I have a use-case in Java where I need to populate one of the lists (say x) based on the id of the other list(say y) and to fetch the result from that list.
List<LightRecruiterScholarResponse> responses = eventScholarRepository.findScholarDetailsByEventId(eventId);
List<InterviewDto> interviewResults = interviewRepository.getInterviewResultByRoundIdAndScholarId();
for (LightRecruiterScholarResponse response : responses) {
String val = null;
for (InterviewDto dto : interviewResults) {
if (dto.getId().equals(response.getScholarId())) {
val = dto.getInterviewResult();
break;
}
}
response.setInterviewStatus(val);
}

You can use:
Map<String, String> map = interviewResults.stream()
.collect(Collectors.toMap(InterviewDto::getId, InterviewDto::getInterviewResult));
responses.forEach(response ->
response.setInterviewStatus(
map.getOrDefault(response.getScholarId(), null)));
The idea is to create a Map of Id for key and InterviewResult for value, and then for each element in responses you set InterviewStatus which you can find it in the map by ScholarId which can replace if (dto.getId().equals(response.getScholarId()))

This could be done straightforward:
List<LightRecruiterScholarResponse> responses =
eventScholarRepository.findScholarDetailsByEventId(eventId);
List<InterviewDto> interviewResults =
interviewRepository.getInterviewResultByRoundIdAndScholarId();
responses.forEach(response -> response.setInterviewStatus(
interviewResults.stream()
.filter(dto -> dto.getId().equals(response.getScholarId()))
.map(InterviewDto::getInterviewResult)
.findFirst().orElse(null)));
This is not very efficient, because you iterate over interviewResults for every response. To fix it, you can build Map and use it:
List<LightRecruiterScholarResponse> responses =
eventScholarRepository.findScholarDetailsByEventId(eventId);
Map<String, String> interviewResults =
interviewRepository.getInterviewResultByRoundIdAndScholarId().stream()
.collect(Collectors.toMap(InterviewDto::getId,
InterviewDto::getInterviewResult));
responses.forEach(response ->
response.setInterviewStatus(interviewResults.get(response.getScholarId())));

Elasticsearch Java API implementation to fetch millions of records

I want to get all doc (millions) in elastic index based on some condition. I used below query in elastic.
GET /<index-name>/_search
{
"from" : 99550, "size" : 500,
"query" : {
"term" : { "CC_ENGAGEMENT_NUMBER" : "1967" }
}
}
And below are my java implementation.
public IndexSearchResult findByStudIdAndcollageId(final String studId, final String collageId,
Integer Page_Number_Start_Index, Integer Total_No_Of_Records) {
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
List<Map<String, Object>> searchResults = new ArrayList<Map<String, Object>>();
IndexSearchResult indexSearchResult = new IndexSearchResult();
try {
QueryBuilder qurBd = new BoolQueryBuilder().minimumShouldMatch(2)
.should(QueryBuilders.matchQuery("STUD_ID", studId).operator(Operator.AND))
.should(QueryBuilders.matchQuery("CLG_ID", collageId).operator(Operator.AND));
sourceBuilder.from(Page_Number_Start_Index).size(Total_No_Of_Records);
sourceBuilder.query(qurBd);
sourceBuilder.sort(new FieldSortBuilder("ROLL_NO.keyword").order(SortOrder.DESC));
SearchRequest searchRequest = new SearchRequest();
searchRequest.indices("clgindex");
searchRequest.source(sourceBuilder);
SearchResponse response;
response = rClient.search(searchRequest, RequestOptions.DEFAULT);
response.getHits().forEach(searchHit -> {
searchResults.add(searchHit.getSourceAsMap());
});
indexSearchResult.setListOfIndexes(searchResults);
log.info("searchResultsHits {}", searchResults.size());
} catch (Exception e) {
log.error("search :: Search on clg flat index. {}", e.getMessage());
}
return indexSearchResult;
}
So if the limit from 99550 and size 500 then it will not fetch more that 1L records.
Error: "reason" : "Result window is too large, from + size must be less than or equal to: [100000] but was [100050]. See the scroll api for a more efficient way to request large data sets. This limit can be set by changing the [index.max_result_window] index level setting."
}
I don't want to change [index.max_result_window]. Only want solution at Java side to search all docs in index based on conditions by implementing elasticserach API.
Thanks in advance..

Get,Put key and values from nested hashmap

I want to create a nested HashMap which returns the frequency of terms among multiple files. Like,
Map<String, Map<String, Integer>> wordToDocumentMap=new HashMap<>();
I have been able to return the number of times a term appears in a file.
Map<String, Integer> map = new HashMap<>();//for frequecy count
String str = "Wikipedia is a free online encyclopedia, created and edited by
volunteers around the world."; //String str suppose a file a.java
// The query string
String query = "edited Wikipedia volunteers";
// Split the given string and the query string on space
String[] strArr = str.split("\\s+");
String[] queryArr = query.split("\\s+");
// Map to hold the frequency of each word of query in the string
Map<String, Integer> map = new HashMap<>();
for (String q : queryArr) {
for (String s : strArr) {
if (q.equals(s)) {
map.put(q, map.getOrDefault(q, 0) + 1);
}
}
}
// Display the map
System.out.println(map);
In my code its count the frequency of the given query Individually. But I want to Map the query term and its frequency with its filenames. I have searched around the web for a solution but am finding it tough to find a solution that applies to me. Any help would be appreciated!

I hope I'm understanding you correctly.
What you want is to be able to read in a list of files and map the file name to the map you create in the code above. So let's start with your code and let's turn it into a function:
public Map<String, Integer> createFreqMap(String str, String query) {
Map<String, Integer> map = new HashMap<>();//for frequecy count
// The query string
String query = "edited Wikipedia volunteers";
// Split the given string and the query string on space
String[] strArr = str.split("\\s+");
String[] queryArr = query.split("\\s+");
// Map to hold the frequency of each word of query in the string
Map<String, Integer> map = new HashMap<>();
for (String q : queryArr) {
for (String s : strArr) {
if (q.equals(s)) {
map.put(q, map.getOrDefault(q, 0) + 1);
}
}
}
// Display the map
System.out.println(map);
return map;
}
OK so now you have a nifty function that makes a map from a string and a query
Now you're going to want to set up a system for reading in a file to a string.
There are a bunch of ways to do this. You can look here for some ways that work for different java versions: https://stackoverflow.com/a/326440/9789673
lets go with this (assuming >java 11):
String content = Files.readString(path, StandardCharsets.US_ASCII);
Where path is the path to the file you want.
Now we can put it all together:
String[] paths = ["this.txt", "that.txt"]
Map<String, Map<String, Integer>> output = new HashMap<>();
String query = "edited Wikipedia volunteers"; //String query = "hello";
for (int i = 0; i < paths.length; i++) {
String content = Files.readString(paths[i], StandardCharsets.US_ASCII);
output.put(paths[i], createFreqMap(content, query);
}

Elasticsearch Java query with combination of AND/OR

I am trying to write a query in Elasticsearch via Spring and Java (Elasticsearch client).
The query is somewhat like:
SELECT *** FROM elasticsearch_index
WHERE isActive = 1 AND
(
(store_code = 41 AND store_genre IN ('01', '03') )
OR (store_code = 40 AND store_genre IN ('02') )
OR (store_code = 42 AND store_genre IN ('05', '06') )
)
AND LATITUDE ...
AND LONGITUDE...
Please know that the parameters within the outer brackets is a Map<Integer, String[]>, so I would iterate over the map to add to AND + OR condition.
I tried with equivalent Java approach but does not seem to work:
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
boolQueryBuilder.must(QueryBuilders.matchQuery("isActive", 1));
BoolQueryBuilder orQuery = QueryBuilders.boolQuery();
for (Entry<Integer, String[]> entry : cvsDepoMapping.entrySet()) {
int key = entry.getKey();
String[] value = entry.getValue();
orQuery.must(QueryBuilders.matchQuery("storeCode", key));
orQuery.must(QueryBuilders.termsQuery("storeGenre", value)); // IN clause
boolQueryBuilder.should(orQuery);
}
But neither is this working nor. I am certain of the solution.
I am struggling to find the Java equivalent conditions for the above condition.
I am using:
Spring Boot 2.1.1.RELEASE
Elasticsearch 6.4.3

within your or query you need to put a nested and query for each entry:
without trying to run it:
BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
boolQueryBuilder.must(QueryBuilders.matchQuery("isActive", 1));
BoolQueryBuilder orQuery = QueryBuilders.boolQuery();
for (Entry<Integer, String[]> entry : cvsDepoMapping.entrySet()) {
BoolQueryBuilder storeQueryBuilder = QueryBuilders.boolQuery();
int key = entry.getKey();
String[] value = entry.getValue();
storeQueryBuilder.must(QueryBuilders.matchQuery("storeCode", key));
storeQueryBuilder.must(QueryBuilders.termsQuery("storeGenre", value)); // IN clause
orQuery.should(storeQueryBuilder);
}
boolQueryBuilder.must(orQuery);

neo4J java query parameters

I have a problem to pass list of string to my parameter {code}
String request = "START sdg=node:Sfamilly(master = {code}) MATCH t-[CONTAINS_SF]->sdg RETURN count(distinct t) as count"
Map<String, Object> params = new HashMap<String, Object>();
List<String> codes = new ArrayList<String>();
codes.add("1234");
codes.add("12345");
params.put("master", codes);
Result<Map<String, Object>> resultMag = neo4jTemplate.query(request,params);
it appears that my parameters are not considered ?
Any idea ?
I use spring data neo4j rest 2.3.0.M1.
Thanks.
Charles.

First of all, I think you wanted to say
params.put("code", codes); // on line 7
More importantly, it seems to me that passing lists is only supported when querying nodes by ID.
Not sure this is the best possible solution, but it should work. It builds a Lucene query first from your parameters, then passes it into your Neo4j query.
private void yourMethod() {
String request = "START sdg=node:Sfamilly({luceneQuery}) MATCH t-[CONTAINS_SF]->sdg RETURN count(distinct t) as count";
Map<String, Object> params = new HashMap<String, Object>();
List<String> codes = new ArrayList<String>();
codes.add("1234");
codes.add("12345");
params.put("luceneQuery", listToParams("master", codes));
Result<Map<String, Object>> resultMag = neo4jTemplate.query(request, params);
}
private String listToParams(String paramName, List<String> params) {
if (params.isEmpty()) {
throw new IllegalArgumentException("Empty params");
}
Iterator<String> paramsIterator = params.iterator();
StringBuilder builder = new StringBuilder(paramName).append(":").append(paramsIterator.next());
while (paramsIterator.hasNext()) {
builder.append(" OR ").append(paramName).append(":").append(paramsIterator.next());
}
return builder.toString();
}