Develop Reference

Java Stream - groupingBy() and counting() when a curtain Condition is met

Given the following class Test
class Test {
String testName;
String studName;
String status;
}
and a list of tests
List<Test> tests = List.of(
new Test("English", "John", "passed"),
new Test("English", "Dave", "passed"),
new Test("Science", "Alex", "failed"),
new Test("Science", "Jane", "failed"),
new Test("History", "Dave", "passed"),
new Test("Mathematics", "Anna", "passed"),
new Test("Mathematics", "Lisa", "passed"),
new Test("Mathematics", "Paul", "failed"),
new Test("Geography", "Mark", "passed"),
new Test("Physics", "John", "failed"));
I need to group by testName and count only where status equals "passed". I need to do the equivalent of below code with streams :
Map<String, Long> result2 = new HashMap<>();
for (Test t : tests) {
result2.putIfAbsent(t.getTestName(), 0L);
if (t.getStatus().equals("passed")) {
result2.computeIfPresent(t.getTestName(), (k, v) -> v + 1);
}
}
The correct and desired output:
{Geography=1, English=2, Science=0, Mathematics=2, History=1, Physics=0}
I'm looking for a stream approach, but couldn't find a solution yet. A simple Collectors.counting will count all, regardless of status "failed/passed":
Map<String, Long> resultCounting = tests.stream()
.collect(Collectors.groupingBy(
Test::getTestName,
Collectors.counting()
));
Output:
{Geography=1, English=2, Science=2, Mathematics=3, History=1, Physics=1}
I thought about filtering beforehand, but then I will loose those subjects where all statuses are "failed".
Map<String, Long> resultFilter = tests.stream()
.filter(t -> t.getStatus().equals("passed"))
.collect(Collectors.groupingBy(
Test::getTestName,
Collectors.counting()
));
Output:
{Geography=1, English=2, Mathematics=2, History=1}
How can I group all tests by testName, but count only those where status is "passed" ?
Is it possible to wrap Collectors.counting() in some kind of condition?

You can achieve the desired result by using collector toMap(keyMapper,valueMapper,mergeFunction).
valueMapper function would either produce 1 or 0 depending on on the status.
Map<String, Integer> passCountByTestName = tests.stream()
.collect(Collectors.toMap(
Test::getTestName,
test -> test.getStatus().equals("passed") ? 1 : 0,
Integer::sum
));
passCountByTestName.forEach((k, v) -> System.out.println(k + " -> " + v));
Output:
Geography -> 1
English -> 2
Science -> 0
Mathematics -> 2
History -> 1
Physics -> 0
Sidenote: it would be better to use boolean or enum as type for the status property instead of relying on string values.

Aggregation and grouping using Hazelcast jet

I am trying to do grouping and aggregation using Hazelcast Jet but it is getting little bit slow as I have to loop through data twice one for creating groupingKey and after that aggregating all data so is there any better and feasible way to it, Please help
Here is my code first I am creating a groupingKey from using my data as grouping is done by multiple keys:
// Fields with which I want to do grouping.
List<String> fields1 = {"Field1", "Field4"};
List<String> cAggCount = {"CountFiled"};
List<String> sumField = {"SumFiled"};
BatchStage<Map<Object, List<Object>>> aggBatchStageDataGroupBy = batchStage
.aggregate(AggregateOperations.groupingBy(jdbcData -> {
Map<String, Object> m = ((Map<String, Object>)jdbcData);
Set<String> jset = m.keySet();
StringBuilder stringBuilder = new StringBuilder("");
fields1.stream().forEach(dataValue -> {
if (!jset.contains(dataValue.toString())) {
stringBuilder.append(null+"").append(",");
} else {
Object k = m.get(dataValue.toString());
if (k == null) {
stringBuilder.append("").append(",");
} else {
stringBuilder.append(k).append(",");
}
}
});
return stringBuilder.substring(0, stringBuilder.length() - 1);
}));
And after that I am doing aggregation on it as below:
BatchStage<List<Map<String, Object>>> aggBatchStageData = aggBatchStageDataGroupBy
.map(data -> {
data.entrySet().stream().forEach(v -> {
Map<String, Object> objectMap = new HashMap<>();
IntStream.range(0, cAggCount).forEach(k -> {
objectMap.put(countAlias.get(k), v.getValue().stream().mapToLong(dataMap -> {
return new BigDecimal(1).intValue();
}).count());
});
}
return mapList;
});
So can we do this whole process in one go instead of doing loop twice like groupigByKey first and than aggregating it.

How to retrieve common keys from two hashMaps and put the result into a ArrayList

I am trying to retrieve common 'keys' from two hashMaps and put the result in a ArrayList. To do that, I have come up with following logic.
List<String> commonList = new ArrayList<String>();
for(String key : mapA.keySet()) {
if(mapB.get(key) !=null ) {
if(mapA.get(key).equals(mapB.get(key))) {
commonList.add(key);
}
}
}
This is the data I added in the maps: mapA & mapB:
mapA.put("abc_ap_bank_accounts,XYZ","6372,43272.6648842593");
mapA.put("abc_ap_bank_accounts_secured_attributes,XYZ","6372,43272.6648829051");
mapA.put("abc_ap_checks,XYZ","56207,43272.676245");
mapA.put("abc_ap_holds,XYZ","9523,43272.6735710995");
mapA.put("abc_ap_holds_dh,XYZ","14,43272.6735710995");
mapA.put("abc_ap_invoice_distributions,XYZ","1573699,43272.6735710995");
mapA.put("abc_ap_invoice_distributions_dh,XYZ","9,43272.6735710995");
mapA.put("abc_ap_invoices,XYZ","141096,43272.6735710995");
mapA.put("abc_ap_invoices_dh,XYZ","47,43272.6735710995");
mapA.put("abc_ap_payment_history,XYZ","454441,43272.6763922106");
mapA.put("abc_ap_payment_methods,XYZ","41,43193.0547537269");
mapA.put("abc_ap_payment_schedules,XYZ","141099,43272.6735710995");
mapA.put("abc_ap_payment_schedules_dh,XYZ","47,43272.6735710995");
mapA.put("abc_ap_terms,XYZ","73,43193.0547620718");
mapA.put("abc_ar_cash_receipts,XYZ","198815,43272.6634247337");
mapA.put("abc_ar_collectors,XYZ","8,43192.4939946643");
mapA.put("abc_ar_customer_contacts,XYZ","4978,43272.6613442824");
mapA.put("abc_ar_customer_site_uses,XYZ","71313,43272.6617516204");
mapA.put("abc_ar_customer_sites,XYZ","38740,43272.6617516204");
mapA.put("abc_ar_customers,XYZ","12521,43272.6617516204");
mapA.put("abc_ar_invoice_distributions,XYZ","2808948,43272.6709406713");
mapA.put("abc_ar_invoice_distributions_dh,XYZ","31412,43272.6709406713");
mapA.put("abc_ar_invoices,XYZ","574107,43272.6709406713");
mapA.put("abc_ar_invoices_dh,XYZ","302,43272.6709406713");
mapA.put("abc_ar_payment_history,XYZ","1408356,43272.6733646759");
mapA.put("abc_ar_payment_schedules,XYZ","717509,43272.6709406713");
mapA.put("abc_ar_payment_schedules_dh,XYZ","8265,43272.6709406713");
mapA.put("abc_ar_receipt_methods,XYZ","2091,43272.660792419");
mapA.put("abc_ar_terms,XYZ","280,43273.3107522222");
mapA.put("abc_bank_branches,XYZ","2876,43272.6490289236");
mapA.put("abc_fa_adjustments,XYZ","861656,43273.1559078472");
mapA.put("abc_fa_adjustments_dh,XYZ","489,43260.0309204977");
mapA.put("abc_fa_asset_books,XYZ","418170,43273.1572042245");
mapA.put("abc_fa_asset_books_dh,XYZ","235,43260.0319078819");
mapA.put("abc_fa_asset_history,XYZ","144660,43273.3568460185");
mapA.put("abc_fa_asset_invoices,XYZ","140527,43277.2888911227");
mapA.put("abc_fa_asset_keywords,XYZ","9,43277.2844361806");
mapA.put("abc_fa_assets,XYZ","140979,43273.3568460185");
mapA.put("abc_fa_assets_dh,XYZ","227,43260.0300720833");
mapA.put("abc_fa_book_controls,XYZ","356,43273.1531339583");
mapA.put("abc_fa_categories,XYZ","331,43231.2057896412");
mapA.put("abc_fa_category_books,XYZ","11137,43231.2057896412");
mapA.put("abc_fa_deprn_detail,XYZ","3023721,43273.1572042245");
mapA.put("abc_fa_deprn_detail_dh,XYZ","792,43273.1572042245");
mapA.put("abc_fa_deprn_summary,XYZ","2978509,43273.1572042245");
mapA.put("abc_fa_deprn_summary_dh,XYZ","792,43273.1572042245");
mapA.put("abc_fa_distribution_history,XYZ","166081,43273.3568460185");
mapA.put("abc_fa_locations,XYZ","849,43271.4159192477");
mapA.put("abc_fa_lookups,XYZ","6776,43192.4939880556");
mapA.put("abc_fa_methods,XYZ","1930,43192.494011713");
mapA.put("abc_fa_periods,XYZ","9661,43273.270426713");
mapA.put("abc_fa_retirements,XYZ","62190,43273.1558409838");
mapA.put("abc_fa_transactions,XYZ","582535,43273.1545858449");
mapA.put("abc_fa_transactions_dh,XYZ","463,43260.0292952546");
mapA.put("abc_fnd_currencies,XYZ","257,43268.6356319097");
mapA.put("abc_fnd_descriptive_flex_column_usages,XYZ","30251,43268.6169408218");
mapA.put("abc_fnd_descriptive_flex_context_labels,XYZ","816,43268.6169408218");
mapA.put("abc_fnd_descriptive_flexs,XYZ","3000,43268.6169408218");
mapA.put("abc_fnd_document_attachments,XYZ","141323,43272.649096169");
mapA.put("abc_fnd_document_categories,XYZ","278,43268.635933831");
mapA.put("abc_fnd_document_category_usages,XYZ","1037,43268.635933831");
mapA.put("abc_fnd_document_entities,XYZ","440,43268.6358883796");
mapA.put("abc_fnd_document_media,XYZ","3044,43272.649096169");
mapA.put("abc_fnd_document_sequence_categories,XYZ","42945,43272.6483789468");
mapA.put("abc_fnd_flex_value_hierarchy,XYZ","27847,43272.6487910069");
mapA.put("abc_fnd_flex_value_sets,XYZ","21808,43272.6487910069");
mapA.put("abc_fnd_flex_value_sets,CBS","936,43180.2485385648");
mapA.put("abc_fnd_flex_values,XYZ","511466,43272.6487910069");
mapA.put("abc_fnd_flex_values,CBS","643030,43180.2485385648");
mapA.put("abc_fnd_flex_values_tl,CBS","643012,43180.2485385648");
mapA.put("abc_fnd_flex_values_tl,XYZ","5626126,43272.6487910069");
mapA.put("abc_fnd_id_flex_segments,CBS","117,43180.2490770023");
mapA.put("abc_fnd_id_flex_segments,XYZ","937,43268.6168802431");
mapA.put("abc_fnd_id_flex_structures,CBS","16,43180.2490770023");
mapA.put("abc_fnd_id_flex_structures,XYZ","219,43268.6168802431");
mapA.put("abc_fnd_lookup_types,CBS","5445,43180.2485133681");
mapA.put("abc_fnd_lookup_types,XYZ","20954,43268.6357395833");
mapA.put("abc_fnd_lookup_values,XYZ","310967,43272.648671331");
mapA.put("abc_fnd_lookup_values,CBS","48696,43180.2485133681");
mapA.put("abc_fnd_profile_option_values,XYZ","25654,43272.6486771875");
mapA.put("abc_fnd_profile_option_values,CBS","1229,43180.248486331");
mapA.put("abc_fnd_profile_options,CBS","694,43180.248486331");
mapA.put("abc_fnd_responsibility,XYZ","3296,43271.3555948032");
mapA.put("abc_fnd_segment_attribute_values,CBS","38,43180.2490770023");
mapA.put("abc_fnd_segment_attribute_values,XYZ","1743,43268.6168802431");
mapA.put("abc_fnd_territories,XYZ","256,43268.6358083449");
mapA.put("abc_fnd_user,XYZ","8045,43272.6486153935");
mapA.put("abc_fnd_user_responsibility,XYZ","51583,43272.6491750463");
mapA.put("abc_geographies,CBS","248,43180.2484406366");
mapA.put("abc_geographies,XYZ","4762,43268.635808125");
mapA.put("abc_gl_alloc_batches,XYZ","133,43272.8261837847");
mapA.put("abc_gl_alloc_formula_lines,XYZ","24940,43272.8261837847");
mapA.put("abc_gl_alloc_formulas,XYZ","4988,43272.8261837847");
mapA.put("abc_gl_auto_alloc_batches,XYZ","34,43268.6176857523");
mapA.put("abc_gl_auto_alloc_sets,XYZ","9,43268.6176857523");
mapA.put("abc_gl_balances,CBS","460591,43180.426733125");
mapA.put("abc_gl_balances,XYZ","531165150,43272.7578364699");
mapA.put("abc_gl_coa_value_sets,CBS","140,43180.2500551736");
mapA.put("abc_gl_coa_value_sets,XYZ","121,43272.6507386227");
mapA.put("abc_gl_coa_values,CBS","3129452,43180.2500551736");
mapA.put("abc_gl_coa_values,XYZ","811785,43272.6507386227");
mapA.put("abc_gl_code_combinations,CBS","68076,43180.2496125116");
mapA.put("abc_gl_code_combinations,XYZ","3451401,43272.6526675232");
mapA.put("abc_gl_daily_conversion_types,CBS","5,43180.2494641898");
mapA.put("abc_gl_daily_conversion_types,XYZ","72,43268.6184428241");
mapA.put("abc_gl_daily_rates,XYZ","122748758,43272.6507345139");
mapA.put("abc_gl_daily_rates,CBS","30318,43180.2494641898");
mapA.put("abc_gl_import_references,XYZ","187095005,43272.6912625694");
mapA.put("abc_gl_import_references,CBS","68692721,43223.6425953125");
mapA.put("abc_gl_import_references_dh,CBS","2419575,43223.6425953125");
mapA.put("abc_gl_import_references_dh,XYZ","2,43145.1443791435");
mapA.put("abc_gl_je_batches,XYZ","2731346,43272.7667763542");
mapA.put("abc_gl_je_batches,CBS","1165,43223.6425953125");
mapA.put("abc_gl_je_batches_dh,XYZ","3382,43272.6912625694");
mapA.put("abc_gl_je_batches_dh,CBS","63,43223.6425953125");
mapA.put("abc_gl_je_categories_tl,CBS","117,43180.2494409607");
mapA.put("abc_gl_je_categories_tl,XYZ","3102,43268.6176579745");
mapA.put("abc_gl_je_headers,XYZ","20096450,43272.7667763542");
mapA.put("abc_gl_je_headers,CBS","4464,43223.6425953125");
mapA.put("abc_gl_je_headers_dh,CBS","100,43223.6425953125");
mapA.put("abc_gl_je_headers_dh,XYZ","592840,43272.6912625694");
mapA.put("abc_gl_je_lines,XYZ","1187455843,43272.7667763542");
mapA.put("abc_gl_je_lines,CBS","3620200,43223.6425953125");
mapA.put("abc_gl_je_lines_dh,XYZ","87553244,43272.6912625694");
mapA.put("abc_gl_je_lines_dh,CBS","69399,43223.6425953125");
mapA.put("abc_gl_je_sources_tl,CBS","43,43180.2494381713");
mapA.put("abc_gl_je_sources_tl,XYZ","3586,43268.6176533565");
mapA.put("abc_gl_ledger_balancing_segments,XYZ","482,43268.6178050579");
mapA.put("abc_gl_ledger_periods,XYZ","49005,43272.6509033681");
mapA.put("abc_gl_ledger_periods,CBS","585,43223.6233088079");
mapA.put("abc_gl_ledger_relationships,CBS","47,43180.2494641088");
mapA.put("abc_gl_ledger_relationships,XYZ","411,43268.6178050579");
mapA.put("abc_gl_ledger_set_assignments,XYZ","843,43268.6178050579");
mapA.put("abc_gl_ledgers,XYZ","418,43268.6178050579");
mapA.put("abc_gl_ledgers,CBS","53,43180.2494641088");
mapA.put("abc_gl_periods,XYZ","678,43189.7832918403");
mapA.put("abc_gl_periods,CBS","65,43223.6233088079");
mapA.put("abc_gl_subledger_distributions,XYZ","34275694,43272.6570907176");
mapA.put("abc_gl_subledger_distributions,CBS","64292586,43224.3809484606");
mapA.put("abc_gl_subledger_distributions_dh,CBS","1293981,43224.3809484606");
mapA.put("abc_gl_subledger_lines,XYZ","14891251,43272.6570907176");
mapA.put("abc_gl_subledger_lines,CBS","34456050,43224.3809484606");
mapA.put("abc_gl_subledger_lines_dh,CBS","721841,43224.3809484606");
mapA.put("abc_gl_subledger_references,CBS","44491269,43224.395238206");
mapA.put("abc_gl_subledger_references,XYZ","85762915,43276.649014456");
mapA.put("abc_hr_assignments,XYZ","561102,43272.7518781019");
mapA.put("abc_hr_assignments_dh,XYZ","8,43242.6042654977");
mapA.put("abc_hr_locations,XYZ","1472,43277.5080027431");
mapA.put("abc_hr_locations_dh,XYZ","1,43180.6461068171");
mapA.put("abc_hr_people,XYZ","561168,43272.7518781019");
mapA.put("abc_hr_people_dh,XYZ","9,43242.6042654977");
mapA.put("abc_hr_pos_structure_elements,XYZ","601,43269.4130085301");
mapA.put("abc_hr_position_structures,XYZ","32,43269.4130085301");
mapA.put("abc_hr_positions,XYZ","449,43269.4130085301");
mapA.put("abc_internal_bank_account_documents,XYZ","252,43272.6610732986");
mapA.put("abc_internal_bank_account_uses,XYZ","1546,43272.7626210532");
mapA.put("abc_internal_bank_accounts,XYZ","1542,43272.7611923843");
mapA.put("abc_internal_bank_accounts_secured_attributes,XYZ","1542,43272.7611923843");
mapA.put("abc_inv_bill_of_materials,XYZ","1124,43269.537615544");
mapA.put("abc_inv_bom_components,XYZ","1892,43269.537615544");
mapA.put("abc_inv_bom_resources,XYZ","38,43268.8932581944");
mapA.put("abc_inv_categories,XYZ","7122,43209.451384456");
mapA.put("abc_inv_item_categories,XYZ","7421625,43272.6554378009");
mapA.put("abc_inv_item_cost_details,XYZ","2449309,43272.6589800926");
mapA.put("abc_inv_item_costs,XYZ","2475153,43272.6589800926");
mapA.put("abc_inv_item_revisions,XYZ","2446153,43272.6585068634");
mapA.put("abc_inv_items,XYZ","2458126,43272.6554378009");
mapA.put("abc_inv_material_transaction_accounts,XYZ","3407129,43272.6614916319");
mapA.put("abc_inv_material_transactions,XYZ","1884933,43272.6614916319");
mapA.put("abc_inv_mtl_transaction_lot_numbers,XYZ","1051994,43272.6614916319");
mapA.put("abc_inv_onhand_quantites,XYZ","35265,43272.6630184722");
mapA.put("abc_inv_parameters,XYZ","960,43272.4247054976");
mapA.put("abc_inv_subinventories,XYZ","2610,43272.4247448727");
mapA.put("abc_inv_units_of_measure,XYZ","110,43192.3447800925");
mapA.put("abc_inv_uom_conversions,XYZ","2936,43192.4352418982");
mapA.put("abc_legal_entities,XYZ","362,43268.6359473032");
mapA.put("abc_legal_entities,CBS","152,43180.2485615972");
mapA.put("abc_legal_entity_registrations,CBS","304,43180.2485615972");
mapA.put("abc_legal_entity_registrations,XYZ","382,43268.6359473032");
mapA.put("abc_om_order_headers,XYZ","78591,43272.6649190509");
mapA.put("abc_om_order_holds,XYZ","182054,43272.6689071065");
mapA.put("abc_om_order_line_history,XYZ","116389,43272.6649190509");
mapA.put("abc_om_order_lines,XYZ","430120,43272.6649190509");
mapA.put("abc_om_price_list_line_attributes,XYZ","537347,43273.4698067477");
mapA.put("abc_om_price_list_lines,XYZ","537460,43273.4698067477");
mapA.put("abc_om_price_list_qualifiers,XYZ","983,43273.4698067477");
mapA.put("abc_om_price_lists,XYZ","1110,43273.4698067477");
mapA.put("abc_om_transaction_types,XYZ","7080,43270.5508769444");
mapA.put("abc_operating_units,XYZ","307,43268.6360601505");
mapA.put("abc_organizations,XYZ","1177,43272.4188616088");
mapA.put("abc_po_action_history,XYZ","168049,43272.6713592014");
mapA.put("abc_po_agents,XYZ","459,43271.6301501505");
mapA.put("abc_po_distributions,XYZ","147056,43272.6676102778");
mapA.put("abc_po_distributions_dh,XYZ","295,43263.7643565741");
mapA.put("abc_po_headers,XYZ","50561,43272.6676102778");
mapA.put("abc_po_headers_dh,XYZ","8,43208.2975749884");
mapA.put("abc_po_lines,XYZ","138843,43272.6676102778");
mapA.put("abc_po_lines_dh,XYZ","96,43272.6676102778");
mapA.put("abc_po_releases,XYZ","675,43272.6676102778");
mapA.put("abc_po_requisition_distributions,XYZ","5098,43272.6653532755");
mapA.put("abc_po_requisition_distributions_dh,XYZ","7,43213.9294613889");
mapA.put("abc_po_requisition_headers,XYZ","4157,43272.6653532755");
mapA.put("abc_po_requisition_headers_dh,XYZ","2,43213.9294613889");
mapA.put("abc_po_requisition_lines,XYZ","4786,43272.6653532755");
mapA.put("abc_po_requisition_lines_dh,XYZ","2,43213.9294613889");
mapA.put("abc_po_vendor_bank_accounts,XYZ","6622,43272.6648829051");
mapA.put("abc_po_vendor_contacts,XYZ","3432,43272.6647480556");
mapA.put("abc_po_vendor_sites,XYZ","17366,43272.6615350694");
mapA.put("abc_po_vendors,XYZ","6840,43272.6615350694");
mapA.put("abc_po_vendors_secured_attributes,XYZ","6840,43272.6615350694");
mapA.put("abc_rcv_shipment_headers,XYZ","63776,43272.6619233333");
mapA.put("abc_rcv_shipment_headers_dh,XYZ","3,43166.9666005787");
mapA.put("abc_rcv_shipment_lines,XYZ","163201,43272.6619233333");
mapA.put("abc_rcv_subledger_lines,XYZ","719678,43272.6638612269");
mapA.put("abc_rcv_transactions,XYZ","334263,43272.6619233333");
mapA.put("abc_tax_accounts,XYZ","3836,43276.6228216088");
mapA.put("abc_tax_codes,XYZ","3046,43276.4820179977");
mapA.put("abc_tax_lines,XYZ","1336810,43272.678131412");
mapA.put("abc_tax_party_profiles,XYZ","623791,43272.6781120949");
mapB.put("abc_ap_bank_accounts_secured_attributes,XYZ","6372,43272.6648829051");
mapB.put("abc_ap_checks,XYZ","56039,43272.676245");
mapB.put("abc_ap_holds,XYZ","9486,43272.6735710995");
mapB.put("abc_ap_holds_dh,XYZ","6,43168.7454254745");
mapB.put("abc_ap_invoice_distributions,XYZ","1568682,43272.6735710995");
mapB.put("abc_ap_invoice_distributions_dh,XYZ","1,43193.0607325115");
mapB.put("abc_ap_invoices,XYZ","137513,43250.3191355903");
mapB.put("abc_ap_invoices_dh,XYZ","32,43193.0607325115");
mapB.put("abc_ap_payment_history,XYZ","452474,43272.6763922106");
mapB.put("abc_ap_payment_methods,XYZ","41,43193.0547537269");
mapB.put("abc_ap_payment_schedules,XYZ","140906,43272.6735710995");
mapB.put("abc_ap_terms,XYZ","73,43193.0547620718");
mapB.put("abc_ar_cash_receipts,XYZ","198605,43272.6634247337");
mapB.put("abc_ar_collectors,XYZ","8,43192.4939946643");
mapB.put("abc_ar_customer_contacts,XYZ","4978,43272.6613442824");
mapB.put("abc_ar_customer_site_uses,XYZ","71231,43272.6617516204");
mapB.put("abc_ar_customer_sites,XYZ","38727,43272.6617516204");
mapB.put("abc_ar_customers,XYZ","12515,43272.6617516204");
mapB.put("abc_ar_invoice_distributions,XYZ","2779621,43262.7610439236");
mapB.put("abc_ar_invoice_distributions_dh,XYZ","26207,43193.8544045255");
mapB.put("abc_ar_invoices,XYZ","573853,43272.6709406713");
mapB.put("abc_ar_invoices_dh,XYZ","235,43193.8544045255");
mapB.put("abc_ar_payment_history,XYZ","21194,43236.3538011806");
mapB.put("abc_ar_payment_schedules,XYZ","717113,43272.6709406713");
mapB.put("abc_ar_payment_schedules_dh,XYZ","6773,43208.2936282523");
mapB.put("abc_ar_receipt_methods,XYZ","2090,43272.660792419");
mapB.put("abc_ar_terms,XYZ","280,43273.3107522222");
mapB.put("abc_bank_branches,XYZ","2875,43272.6490289236");
mapB.put("abc_fa_adjustments,XYZ","861031,43273.1559078472");
mapB.put("abc_fa_adjustments_dh,XYZ","426,43100.865825625");
mapB.put("abc_fa_asset_books,XYZ","417647,43273.1572042245");
mapB.put("abc_fa_asset_books_dh,XYZ","211,43100.8665157407");
mapB.put("abc_fa_asset_history,XYZ","144647,43273.3568460185");
mapB.put("abc_fa_asset_invoices,XYZ","140409,43260.0309616204");
mapB.put("abc_fa_asset_keywords,XYZ","9,43277.2844361806");
mapB.put("abc_fa_assets,XYZ","140838,43260.0300720833");
mapB.put("abc_fa_assets_dh,XYZ","209,43100.8654389931");
mapB.put("abc_fa_book_controls,XYZ","368,43273.1531339583");
mapB.put("abc_fa_categories,XYZ","331,43231.2057896412");
mapB.put("abc_fa_category_books,XYZ","11137,43231.2057896412");
mapB.put("abc_fa_deprn_detail,XYZ","3022367,43273.1572042245");
mapB.put("abc_fa_deprn_detail_dh,XYZ","261,43193.8467169444");
mapB.put("abc_fa_deprn_summary,XYZ","2977196,43273.1572042245");
mapB.put("abc_fa_deprn_summary_dh,XYZ","261,43193.8467169444");
mapB.put("abc_fa_distribution_history,XYZ","166068,43273.3568460185");
mapB.put("abc_fa_locations,XYZ","849,43271.4159192477");
mapB.put("abc_fa_lookups,XYZ","6776,43192.4939880556");
mapB.put("abc_fa_methods,XYZ","1930,43192.494011713");
mapB.put("abc_fa_periods,XYZ","9643,43273.270426713");
mapB.put("abc_fa_retirements,XYZ","62167,43273.1558409838");
mapB.put("abc_fa_transactions,XYZ","581980,43273.1545858449");
mapB.put("abc_fa_transactions_dh,XYZ","420,43100.8651175347");
mapB.put("abc_fnd_currencies,XYZ","257,43268.6356319097");
mapB.put("abc_fnd_descriptive_flex_column_usages,XYZ","30251,43268.6169408218");
mapB.put("abc_fnd_descriptive_flex_context_labels,XYZ","814,43199.6273292361");
mapB.put("abc_fnd_descriptive_flexs,XYZ","3000,43268.6169408218");
mapB.put("abc_fnd_document_attachments,XYZ","140965,43272.649096169");
mapB.put("abc_fnd_document_categories,XYZ","278,43268.635933831");
mapB.put("abc_fnd_document_category_usages,XYZ","1037,43268.635933831");
mapB.put("abc_fnd_document_entities,XYZ","440,43268.6358883796");
mapB.put("abc_fnd_document_media,XYZ","3043,43272.649096169");
mapB.put("abc_fnd_document_sequence_categories,XYZ","42945,43272.6483789468");
mapB.put("abc_fnd_flex_value_hierarchy,XYZ","27563,43235.7319845602");
mapB.put("abc_fnd_flex_value_sets,XYZ","21808,43272.6487910069");
mapB.put("abc_fnd_flex_value_sets,CBS","936,43180.2485385648");
mapB.put("abc_fnd_flex_values,XYZ","511443,43272.6487910069");
mapB.put("abc_fnd_flex_values,CBS","643030,43180.2485385648");
mapB.put("abc_fnd_flex_values_tl,CBS","643012,43180.2485385648");
mapB.put("abc_fnd_flex_values_tl,XYZ","5625873,43272.6487910069");
mapB.put("abc_fnd_id_flex_segments,CBS","117,43180.2490770023");
mapB.put("abc_fnd_id_flex_segments,XYZ","937,43268.6168802431");
mapB.put("abc_fnd_id_flex_structures,CBS","16,43180.2490770023");
mapB.put("abc_fnd_id_flex_structures,XYZ","219,43268.6168802431");
mapB.put("abc_fnd_lookup_types,CBS","5445,43180.2485133681");
mapB.put("abc_fnd_lookup_types,XYZ","20954,43268.6357395833");
mapB.put("abc_fnd_lookup_values,XYZ","310978,43272.648671331");
mapB.put("abc_fnd_lookup_values,CBS","48696,43180.2485133681");
mapB.put("abc_fnd_profile_option_values,XYZ","25652,43272.6486771875");
mapB.put("abc_fnd_profile_option_values,CBS","1229,43180.248486331");
mapB.put("abc_fnd_profile_options,CBS","694,43180.248486331");
mapB.put("abc_fnd_responsibility,XYZ","3296,43271.3555948032");
mapB.put("abc_fnd_segment_attribute_values,CBS","38,43180.2490770023");
mapB.put("abc_fnd_segment_attribute_values,XYZ","1743,43199.6271230556");
mapB.put("abc_fnd_territories,XYZ","256,43268.6358083449");
mapB.put("abc_fnd_user,XYZ","8068,43272.6486153935");
mapB.put("abc_fnd_user_responsibility,XYZ","51559,43272.6491750463");
mapB.put("abc_geographies,CBS","248,43180.2484406366");
mapB.put("abc_geographies,XYZ","4762,43268.635808125");
mapB.put("abc_gl_alloc_batches,XYZ","133,43272.8261837847");
mapB.put("abc_gl_alloc_formula_lines,XYZ","24940,43272.8261837847");
mapB.put("abc_gl_alloc_formulas,XYZ","4988,43272.8261837847");
mapB.put("abc_gl_auto_alloc_batches,XYZ","34,43268.6176857523");
mapB.put("abc_gl_auto_alloc_sets,XYZ","9,43268.6176857523");
mapB.put("abc_gl_balances,CBS","460591,43180.426733125");
mapB.put("abc_gl_balances,XYZ","508033315,43230.3016400347");
mapB.put("abc_gl_coa_value_sets,CBS","140,43180.2500551736");
mapB.put("abc_gl_coa_value_sets,XYZ","121,43265.8065184375");
mapB.put("abc_gl_coa_values,CBS","3129452,43180.2500551736");
mapB.put("abc_gl_coa_values,XYZ","811785,43272.6507386227");
mapB.put("abc_gl_code_combinations,CBS","68076,43180.2496125116");
mapB.put("abc_gl_code_combinations,XYZ","3426235,43256.2275320255");
mapB.put("abc_gl_daily_conversion_types,CBS","5,43180.2494641898");
mapB.put("abc_gl_daily_conversion_types,XYZ","72,43268.6184428241");
mapB.put("abc_gl_daily_rates,XYZ","122019188,43272.6507345139");
mapB.put("abc_gl_daily_rates,CBS","30318,43180.2494641898");
mapB.put("abc_gl_import_references,XYZ","186457872,43264.3415345602");
mapB.put("abc_gl_import_references,CBS","7969012,43181.2955106944");
mapB.put("abc_gl_import_references_dh,XYZ","26604513,43145.1577739005");
mapB.put("abc_gl_je_batches,XYZ","2728068,43272.7667763542");
mapB.put("abc_gl_je_batches,CBS","588,43181.2955106944");
mapB.put("abc_gl_je_batches_dh,XYZ","2042,43168.746250706");
mapB.put("abc_gl_je_categories_tl,CBS","117,43180.2494409607");
mapB.put("abc_gl_je_categories_tl,XYZ","3102,43268.6176579745");
mapB.put("abc_gl_je_headers,XYZ","19215835,43214.4233078356");
mapB.put("abc_gl_je_headers,CBS","1178,43181.2955106944");
mapB.put("abc_gl_je_headers_dh,XYZ","581442,43168.746250706");
mapB.put("abc_gl_je_lines,XYZ","365870724,43193.8699508565");
mapB.put("abc_gl_je_lines_dh,XYZ","852720389,43193.8699508565");
mapB.put("abc_gl_je_sources_tl,CBS","43,43180.2494381713");
mapB.put("abc_gl_je_sources_tl,XYZ","3586,43214.3266307176");
mapB.put("abc_gl_ledger_balancing_segments,XYZ","482,43268.6178050579");
mapB.put("abc_gl_ledger_periods,XYZ","48873,43221.7804195602");
mapB.put("abc_gl_ledger_periods,CBS","1940,43180.2497818055");
mapB.put("abc_gl_ledger_relationships,CBS","47,43180.2494641088");
mapB.put("abc_gl_ledger_relationships,XYZ","411,43268.6178050579");
mapB.put("abc_gl_ledger_set_assignments,XYZ","843,43268.6178050579");
mapB.put("abc_gl_ledgers,XYZ","418,43268.6178050579");
mapB.put("abc_gl_ledgers,CBS","53,43180.2494641088");
mapB.put("abc_gl_periods,XYZ","678,43189.7832918403");
mapB.put("abc_gl_periods,CBS","235,43180.2497818055");
mapB.put("abc_gl_subledger_distributions,XYZ","34117841,43272.6570907176");
mapB.put("abc_gl_subledger_distributions,CBS","17608620,43180.5930337731");
mapB.put("abc_gl_subledger_lines,XYZ","14869523,43272.6570907176");
mapB.put("abc_gl_subledger_references,CBS","11953274,43181.3702182407");
mapB.put("abc_gl_subledger_references,XYZ","63347683,43228.2754828704");
mapB.put("abc_hr_assignments,XYZ","553663,43236.2802898148");
mapB.put("abc_hr_assignments_dh,XYZ","6,43181.3084185185");
mapB.put("abc_hr_locations,XYZ","1472,43272.4184375463");
mapB.put("abc_hr_locations_dh,XYZ","1,43180.6461068171");
mapB.put("abc_hr_people,XYZ","561134,43272.7518781019");
mapB.put("abc_hr_people_dh,XYZ","7,43195.5174862037");
mapB.put("abc_hr_pos_structure_elements,XYZ","601,43269.4130085301");
mapB.put("abc_hr_position_structures,XYZ","32,43269.4130085301");
mapB.put("abc_hr_positions,XYZ","449,43269.4130085301");
mapB.put("abc_internal_bank_account_documents,XYZ","252,43272.6610732986");
mapB.put("abc_internal_bank_account_uses,XYZ","1546,43272.7626210532");
mapB.put("abc_internal_bank_accounts,XYZ","1542,43272.7611923843");
mapB.put("abc_internal_bank_accounts_secured_attributes,XYZ","1542,43272.7611923843");
mapB.put("abc_inv_bill_of_materials,XYZ","1113,43256.9769808102");
mapB.put("abc_inv_bom_components,XYZ","1884,43256.9769808102");
mapB.put("abc_inv_bom_resources,XYZ","38,43268.8932581944");
mapB.put("abc_inv_categories,XYZ","7122,43209.451384456");
mapB.put("abc_inv_item_categories,XYZ","6935747,43236.0593178819");
mapB.put("abc_inv_item_cost_details,XYZ","2302085,43236.3459391898");
mapB.put("abc_inv_item_costs,XYZ","2475112,43272.6589800926");
mapB.put("abc_inv_item_revisions,XYZ","2292783,43236.0599286343");
mapB.put("abc_inv_items,XYZ","2390687,43269.4204171296");
mapB.put("abc_inv_material_transaction_accounts,XYZ","3403795,43272.6614916319");
mapB.put("abc_inv_material_transactions,XYZ","1878570,43271.3665466782");
mapB.put("abc_inv_mtl_transaction_lot_numbers,XYZ","1050852,43272.6614916319");
mapB.put("abc_inv_onhand_quantites,XYZ","35102,43236.348574213");
mapB.put("abc_inv_parameters,XYZ","937,43213.9215269097");
mapB.put("abc_inv_subinventories,XYZ","2578,43262.6031176273");
mapB.put("abc_inv_units_of_measure,XYZ","110,43192.3447800925");
mapB.put("abc_inv_uom_conversions,XYZ","2936,43161.5500064352");
mapB.put("abc_legal_entities,XYZ","357,43221.5564825579");
mapB.put("abc_legal_entities,CBS","152,43180.2485615972");
mapB.put("abc_legal_entity_registrations,CBS","304,43180.2485615972");
mapB.put("abc_legal_entity_registrations,XYZ","382,43268.6359473032");
mapB.put("abc_om_order_headers,XYZ","76573,43228.0120184722");
mapB.put("abc_om_order_holds,XYZ","175925,43236.3503649421");
mapB.put("abc_om_order_line_history,XYZ","115956,43227.6775010648");
mapB.put("abc_om_order_lines,XYZ","423428,43228.0120184722");
mapB.put("abc_om_price_list_line_attributes,XYZ","501017,43219.8392744329");
mapB.put("abc_om_price_list_lines,XYZ","501138,43235.7412509491");
mapB.put("abc_om_price_list_qualifiers,XYZ","850,43145.0203525347");
mapB.put("abc_om_price_lists,XYZ","972,43235.7412509491");
mapB.put("abc_om_transaction_types,XYZ","6758,43168.7371143403");
mapB.put("abc_operating_units,XYZ","304,43199.6260239236");
mapB.put("abc_organizations,XYZ","1162,43243.4052112153");
mapB.put("abc_po_action_history,XYZ","162702,43228.0189270486");
mapB.put("abc_po_agents,XYZ","454,43227.9012679282");
mapB.put("abc_po_distributions,XYZ","143165,43236.3490382523");
mapB.put("abc_po_distributions_dh,XYZ","277,43192.3468581482");
mapB.put("abc_po_headers,XYZ","50111,43269.4335298843");
mapB.put("abc_po_headers_dh,XYZ","7,43166.9742898611");
mapB.put("abc_po_lines,XYZ","137762,43269.3004224306");
mapB.put("abc_po_lines_dh,XYZ","92,43192.3468581482");
mapB.put("abc_po_releases,XYZ","675,43272.6676102778");
mapB.put("abc_po_requisition_distributions,XYZ","4916,43235.8636478704");
mapB.put("abc_po_requisition_distributions_dh,XYZ","1,43162.1648364236");
mapB.put("abc_po_requisition_headers,XYZ","4016,43235.8636478704");
mapB.put("abc_po_requisition_headers_dh,XYZ","1,43162.1648364236");
mapB.put("abc_po_requisition_lines,XYZ","4600,43235.8636478704");
mapB.put("abc_po_requisition_lines_dh,XYZ","1,43162.1648364236");
mapB.put("abc_po_vendor_bank_accounts,XYZ","6623,43272.6648829051");
mapB.put("abc_po_vendor_contacts,XYZ","3432,43272.6647480556");
mapB.put("abc_po_vendor_sites,XYZ","17351,43272.6615350694");
mapB.put("abc_po_vendors,XYZ","6838,43272.6615350694");
mapB.put("abc_po_vendors_secured_attributes,XYZ","6838,43272.6615350694");
mapB.put("abc_rcv_shipment_headers,XYZ","60902,43228.0108643634");
mapB.put("abc_rcv_shipment_headers_dh,XYZ","3,43166.9666005787");
mapB.put("abc_rcv_shipment_lines,XYZ","155335,43228.0108643634");
mapB.put("abc_rcv_subledger_lines,XYZ","48244,43272.6638612269");
mapB.put("abc_rcv_transactions,XYZ","316780,43228.0108643634");
mapB.put("abc_tax_accounts,XYZ","3836,43276.6228216088");
mapB.put("abc_tax_codes,XYZ","3046,43276.4820179977");
mapB.put("abc_tax_lines,XYZ","1335168,43272.678131412");
mapB.put("abc_tax_party_profiles,XYZ","11039,43272.6781120949");
mapB.put("abc_tax_party_profiles,XYZ","11039,6/21/18 16:16");
There are a total of 219 entries in mapA & 210 in mapB. When I run the logic from the beginning of this question, I get the output of total 79 entries whereas Microsoft Excel with a Macro gives me 210 common keys.
How can I check both the HashMaps: mapA & mapB and retrieve the common keys in both the HashMaps ?
Could anyone let me know the mistake I am doing here ?

In your current code, you are actually comparing the values for a given key, from the two maps. In fact, you really just want to take the intersection of the two keysets here, so do just that:
Set<String> s1 = mapA.keySet();
Set<String> s2 = mapB.keySet();
s1.retainAll(s2);
List<String> result = new ArrayList<>();
result.addAll(s1);
If we are concerned about not destroying the original mapA map, then we can instead make a copy of the key set from that map:
TreeSet<String> s1 = new TreeSet<String>(mapA.keySet());
Set<String> s2 = mapB.keySet();
s1.retainAll(s2);
List<String> result = new ArrayList<>();
result.addAll(s1);

The problem you check the equality of the values according to the keys and not the keys themselves.
List<String> commonList = new ArrayList<String>();
for(String key : mapA.keySet()) {
if (mapB.containsKey(key)) {
commonList.add(key);
}
}
Since the keys are by definition unique, I suggest you use HashSet. The method retainAll retains only the elements in the set that are contained in another one.
Set<String> keys = new HashSet<>(mapA.keySet()).retainAll(mapB.keySet());

You can make use of the retainAll() method:
Set<String> commonSet = new HashSet<>(mapA.keySet());
Set<String> setB = mapB.keySet();
commonSet.retainAll(setB);

You're checking equal values, not equal keys. You can do your check if you write if(mapA.containsKey(key))) (and change the != null check to containsKey as well, since it's usually faster)
You can also just use Set.retainAll and pass in both keySets of the Maps
Set<String> keys = new HashSet<>( mapA.keySet() );
keys.retainAll( mapB.keySet() );

You can also do this with Java8's stream.
List<String> intersection = mapA.keySet()
.stream()
.filter(mapB.keySet()::contains)
.collect(Collectors.toList());
System.out.println(intersection.size());

The mapB has only 209 entries, because the two last have the same key.
Your code compares the data as well, so 79 is the common keys that have the same data in both maps. Is that what do you want?
If you want only the common keys, you simply need to do the intersection of the two sets os keys. You can do this with the method "retainAll" as the example below. This method retains in the SET only all values that are in the other SET too. The result is 209 (instead of 210), as the mapB has only 209 unique keys.
public class Test {
public void test() {
final List<String> commonList = new ArrayList<String>();
final Map<String, String> mapA = new HashMap<>();
final Map<String, String> mapB = new HashMap<>();
fillA(mapA);
System.out.println("Size A: " + mapA.size());
fillB(mapB);
System.out.println("Size B: " + mapB.size());
for (final String key : mapA.keySet()) {
if (mapB.get(key) != null) {
if (mapA.get(key).equals(mapB.get(key))) {
commonList.add(key);
}
}
}
System.out.println("CommonList: " + commonList.size());
final Set<String> keySetA = mapA.keySet();
final Set<String> keySetB = mapB.keySet();
final Set<String> commonKeySet = new HashSet<>(keySetA);
commonKeySet.retainAll(keySetB);
System.out.println("CommonKey:" + commonKeySet.size());
}
private void fillA(Map<String, String> mapA) {
// put your A data here
}
private void fillB(Map<String, String> mapB) {
// put your B data here
}
}

scan count returns significantly less number for a dynamodb table

I'm running a sample java program to query a dynamodb table, the table has about 90000 items but when i get the scan count from java it shows only 1994 items
ScanRequest scanRequest = new ScanRequest().withTableName(tableName);
ScanResult result = client.scan(scanRequest);
System.out.println("#items:" + result.getScannedCount());
the program outputs #items:1994
but the detail from amazon aws console shows:
Item Count*: 89249
any idea?
thanks

scanning or querying dynamodb only returns maximum of 1MB of data.
the count is the number of return items fit in 1MB. in order to get the whole table, you should aggressively scan the database until the value LastEvaluatedKey is null

Set your book object with correct hash key value, and use DynamoDBMapper to get the count.
DynamoDBQueryExpression<Book> queryExpression = new DynamoDBQueryExpression<Book>()
.withHashKeyValues(book);
dynamoDbMapper.count(Book.class, queryExpression);

This should help . Worked for me
AmazonDynamoDB client = AmazonDynamoDBClientBuilder.standard()
.withRegion("your region").build();
DynamoDB dynamoDB = new DynamoDB(client);
TableDescription tableDescription = dynamoDB.getTable("table name").describe();
tableDescription.getItemCount();

Based on answer from nightograph
private ArrayList<String> fetchItems() {
ArrayList<String> ids = new ArrayList<>();
ScanResult result = null;
do {
ScanRequest req = new ScanRequest();
req.setTableName("table_name");
if (result != null) {
req.setExclusiveStartKey(result.getLastEvaluatedKey());
}
result = amazonDynamoDBClient.scan(req);
List<Map<String, AttributeValue>> rows = result.getItems();
for (Map<String, AttributeValue> map : rows) {
AttributeValue v = map.get("rangeKey");
String id = v.getS();
ids.add(id);
}
} while (result.getLastEvaluatedKey() != null);
System.out.println("Result size: " + ids.size());
return ids;
}

I agreed with nightograph. I thinks this link is useful.
http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html
I just tested with this example. Anyway this is the Dyanamodb v2.
final ScanRequest scanRequest = new ScanRequest()
.withTableName("table_name");
final ScanResult result = dynamoDB.scan(scanRequest);
return result.getCount();

Hash of Hashes of Arrays in Java

I'm trying to implement Hash of Hashes of Arrays in Java and thought it would be nice if I will use anonymous blah blah(i forgot the exact term/I dont know how to call it).
HashMap<String, HashMap<String, String[]>> teams =
new HashMap<String, HashMap<String, String[]>>(){{
put("east", new HashMap<String, String[]>(){{
put("atlantic", new String[] { "bkn", "bos", "phi","tor", "ny" });
put("central", new String[] { "chi", "cle", "det", "ind", "mil" });
put("southeast", new String[] { "atl", "cha", "mia", "orl", "wsh" });
}});
put("west", new HashMap<String, String[]>(){{
put("northwest", new String[] { "den", "min", "okc", "por", "utah" });
put("pacific", new String[] { "gs", "lac", "lal", "phx", "sac" });
put("southwest", new String[] { "dal", "hou", "mem", "no", "sa" });
}});
}};
My question is if there is a another way to implement taking readability into consideration or completely perhaps completely change the implementation?
I know java is not the right tool but my boss told me to do so.
Also, please let me know of the right term. TIA

As long as we're not caring about run speed, why not use a language designed to express tiered data structures like JSON? JAVA has great external library support for it ...
Gson to the rescue!
#SuppressWarnings("unchecked")
HashMap teams =
new Gson().fromJson(
"{'east' : { 'atlantic' : ['bkn', 'bos', 'phi','tor', 'ny']," +
" 'central' : ['chi', 'cle', 'det', 'ind', 'mil']," +
" 'southeast' : ['atl', 'cha', 'mia', 'orl', 'wsh']}," +
" 'west' : { 'northwest' : ['den', 'min', 'okc', 'por', 'utah']," +
" 'pacific' : ['gs', 'lac', 'lal', 'phx', 'sac']," +
" 'southwest' : ['dal', 'hou', 'mem', 'no', 'sa']}}",
HashMap.class
);
http://code.google.com/p/google-gson/

Using a helper method
private void addTeams(String area, String codes) {
String[] areas = area.split("/");
Map<String, String[]> map = teams.get(areas[0]);
if (map == null) teams.put(areas[0], map = new HashMap<String, String[]>());
map.put(areas[1], codes.split(", ?"));
}
Map<String, Map<String, String[]>> teams = new HashMap<String, Map<String, String[]>>();{
addTeams("east/atlantic", "bkn, bos, phi, tor, ny");
addTeams("east/central", "chi, cle, det, ind, mil");
addTeams("east/southeast", "atl, cha, mia, orl, wsh");
addTeams("west/northwest", "den, min, okc, por, utah");
addTeams("west/pacific", "gs, lac, lal, phx, sac");
addTeams("west.southwest", "dal, hou, mem, no, sa");
}
You can replace
new String[] { "bkn", "bos", "phi","tor", "ny" }
with
"bkn,bos,phi,tor,ny".split(",");