private JdbcIdentity getIdentity() {
if (this.identity == null) {
JdbcSecurityRealm.this
.queryConfiguration
.stream()
.map(
queryConfiguration -> {
return executePrincipalQuery(
queryConfiguration,
resultSet -> {
if (resultSet.next()) {
MapAttributes attributes = new MapAttributes();
do {
queryConfiguration
.getColumnMappers(AttributeMapper.class)
.forEach(
attributeMapper -> {
try {
Object value = attributeMapper.map(resultSet);
if (value != null) {
attributes.addFirst(
attributeMapper.getName(), value.toString());
}
} catch (SQLException cause) {
throw log.ldapRealmFailedObtainAttributes(this.name, cause);
}
});
} while (resultSet.next());
return attributes;
}
return null;
});
})
.collect(
Collectors.reducing(
(lAttribute, rAttribute) -> {
MapAttributes attributes = new MapAttributes(lAttribute);
for (Attributes.Entry rEntry : rAttribute.entries()) {
attributes.get(rEntry.getKey()).addAll(rEntry);
}
return attributes;
}))
.ifPresent(attributes -> this.identity = new JdbcIdentity(attributes));
}
return this.identity;
}
public static void main(String[] args) {
final List<Person> people =
Arrays.asList(
new Person("Robert", 49),
new Person("John", 20),
new Person("Sara", 21),
new Person("Chloe", 18),
new Person("Jane", 21),
new Person("Greg", 35));
List<Person> olderThan20_a = new ArrayList<>();
people.stream().filter(person -> person.age > 20).forEach(person -> olderThan20_a.add(person));
printPeople("don't trust olderThan20_a", olderThan20_a);
List<Person> olderThan20_b =
people
.stream()
.filter(person -> person.age > 20)
.collect(ArrayList::new, ArrayList::add, ArrayList::addAll);
printPeople("don't trust olderThan20_b", olderThan20_b);
List<Person> olderThan20_c =
people.stream().filter(person -> person.age > 20).collect(Collectors.toList());
printPeople("don't trust olderThan20_c", olderThan20_c);
Map<Integer, List<Person>> peopleByAge =
people.stream().collect(Collectors.groupingBy(person -> person.age));
System.out.println("Grouped by age: " + peopleByAge);
Map<Integer, List<String>> nameOfPeopleByAge =
people
.stream()
.collect(
Collectors.groupingBy(
person -> person.age,
Collectors.mapping(person -> person.name, Collectors.toList())));
System.out.println("People grouped by age: " + nameOfPeopleByAge);
// Group the names by their first char and then get the oldest person in
// each group
Comparator<Person> byAge = Comparator.comparing(person -> person.age);
Map<Character, Optional<Person>> oldestPersonOfEachLetter =
people
.stream()
.collect(
Collectors.groupingBy(
person -> person.name.charAt(0),
Collectors.reducing(BinaryOperator.maxBy(byAge))));
System.out.println("Oldest person of each letter:");
System.out.println(oldestPersonOfEachLetter);
}
public static void main(String[] args) {
final List<Person> people =
Arrays.asList(
new Person("John", 20),
new Person("Sara", 21),
new Person("Jane", 21),
new Person("Greg", 35));
List<Person> olderThan20 =
people
.stream()
.filter(person -> person.getAge() > 20)
.collect(ArrayList::new, ArrayList::add, ArrayList::addAll);
System.out.println("People older than 20: " + olderThan20);
List<Person> olderThan20_1 =
people.stream().filter(person -> person.getAge() > 20).collect(Collectors.toList());
System.out.println("People older than 20: " + olderThan20_1);
Map<Integer, List<Person>> peopleByAge =
people.stream().collect(Collectors.groupingBy(Person::getAge));
System.out.println("Grouped by age: " + peopleByAge);
Map<Integer, List<String>> nameOfPeopleByAge =
people
.stream()
.collect(
Collectors.groupingBy(
Person::getAge, Collectors.mapping(Person::getName, Collectors.toList())));
System.out.println("People name grouped by age: " + nameOfPeopleByAge);
Comparator<Person> byAge = Comparator.comparing(Person::getAge);
Map<Character, Optional<Person>> oldestPersonOfEachCharacter =
people
.stream()
.collect(
Collectors.groupingBy(
person -> person.getName().charAt(0),
Collectors.reducing(BinaryOperator.maxBy(byAge))));
System.out.println("Oldest person of each letter: " + oldestPersonOfEachCharacter);
}
/**
* 聚集计算
*
* @param dataList 待计算的数据
* @param query 原始查询请求
* @return LinkedList<ResultRecord> 计算后的数据
*/
public static List<SearchIndexResultRecord> aggregate(
List<SearchIndexResultRecord> dataList, int dimSize, List<QueryMeasure> queryMeasures) {
if (CollectionUtils.isEmpty(queryMeasures) || CollectionUtils.isEmpty(dataList)) {
LOGGER.info("no need to group.");
return dataList;
}
Set<Integer> countIndex = Sets.newHashSet();
for (int i = 0; i < queryMeasures.size(); i++) {
if (queryMeasures.get(i).getAggregator().equals(Aggregator.DISTINCT_COUNT)) {
if (LOGGER.isDebugEnabled()) {
LOGGER.info(queryMeasures.get(i) + " ============= begin print values ===== ====");
final int tmp = i;
dataList.forEach(rs -> LOGGER.info(rs.getField(tmp) + ""));
LOGGER.info(" ============= end print measure values ==============");
}
countIndex.add(i);
}
}
int arraySize = dataList.get(0).getFieldArraySize();
long current = System.currentTimeMillis();
Stream<SearchIndexResultRecord> stream =
dataList.size() > 300000 ? dataList.parallelStream() : dataList.stream();
int defaultSize = (int) (dataList.size() > 100 ? dataList.size() * 0.01 : dataList.size());
final BinaryOperator<SearchIndexResultRecord> reduceOperation =
(x, y) -> {
if (!y.getGroupBy().equals(x.getGroupBy())) {
x = SearchIndexResultRecord.of(arraySize);
x.setGroupBy(y.getGroupBy());
for (int i = 0; i < dimSize; i++) {
x.setField(i, y.getField(i));
}
}
try {
int index = dimSize;
for (int i = 0; i < queryMeasures.size(); i++) {
QueryMeasure measure = queryMeasures.get(i);
index = i + dimSize;
if (measure.getAggregator().equals(Aggregator.DISTINCT_COUNT)) {
if (!x.getDistinctMeasures().containsKey(i)) {
x.getDistinctMeasures().put(i, new HashSet<>(defaultSize));
}
if (y.getDistinctMeasures().containsKey(i)) {
x.getDistinctMeasures().get(i).addAll(y.getDistinctMeasures().get(i));
} else if (y.getField(index) != null) {
x.getDistinctMeasures().get(i).add(y.getField(index));
}
} else {
x.setField(
index, measure.getAggregator().aggregate(x.getField(index), y.getField(index)));
}
}
} catch (Exception e) {
throw new RuntimeException(e);
}
return x;
};
final Collector<SearchIndexResultRecord, ?, SearchIndexResultRecord> reducing =
Collectors.reducing(SearchIndexResultRecord.of(arraySize), reduceOperation);
Map<String, SearchIndexResultRecord> groupResult =
stream.collect(
Collectors.groupingByConcurrent(SearchIndexResultRecord::getGroupBy, reducing));
if (CollectionUtils.isNotEmpty(countIndex)) {
groupResult
.values()
.forEach(
record -> {
for (int index : countIndex) {
if (record.getDistinctMeasures() != null
&& record.getDistinctMeasures().containsKey(index)) {
record.setField(
dimSize + index, record.getDistinctMeasures().get(index).size());
}
}
});
}
LOGGER.info(
"group agg(sum) cost: {}ms, size:{}!",
(System.currentTimeMillis() - current),
groupResult.size());
return new ArrayList<>(groupResult.values());
}