| #Java - Code Snippets for '#Map' - 38 code snippet(s) found |
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 Sample 1. Given a Map with Country Name as key and its capitals as values, Find the name of countries having more than 1 capital ? | |
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Map<String,List<String>> capitals = new HashMap();
capitals.put("United States", Arrays.asList("Washington DC"));
capitals.put("Canada", Arrays.asList("Ottawa"));
capitals.put("South Africa", Arrays.asList("Pretoria", "Cape Down", "Bloemfontein"));
for(Map.Entry<String,List<String>> entry: capitals.entrySet()){
if(entry.getValue().size() > 1){
System.out.println(entry.getKey());
}
}
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 Like  Feedback  Map of String and List |
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| Sample 2. Usage of Apache Commons - ArrayListValuedHashMap | |
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ListValuedMap<String,String> listValuedMap = new ArrayListValuedHashMap();
listValuedMap.put("United States", "Washington");
listValuedMap.put("Canada", "Ottawa");
listValuedMap.put("Canada", "Ottawa");
listValuedMap.put("South Africa", "Pretoria");
listValuedMap.put("South Africa", "Cape Town");
listValuedMap.put("South Africa", "Bloemfontein");
System.out.println(listValuedMap); // Values being added to the List and allow even duplicates
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| Like Feedback apache commons apache commons collections ArrayListValuedHashMap ListValuedMap |
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| Sample 3. Method to remove duplicates from a Map ( string and List of objects ) by matching the member field of the object. | |
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Map<String,List<ClassInfoBean>> removeDuplicates(Map<String, List<ClassInfoBean>> interfaceMap){
Map<String, List<ClassInfoBean>> interfaceMapWithoutDuplicate = new HashMap();
for(Map.Entry<String, List<ClassInfoBean>> entry: interfaceMap.entrySet()){
List<ClassInfoBean> classListWithoutDuplicate = new ArrayList();
boolean alreadyContain = false;
for(ClassInfoBean classes: entry.getValue()){
for(ClassInfoBean classes1: classListWithoutDuplicate){
if(classes1.name.equalsIgnoreCase(classes.name)){
alreadyContain = true;
break;
}
}
if(alreadyContain == false){
classListWithoutDuplicate.add(classes);
}
}
interfaceMapWithoutDuplicate.put(entry.getKey(), classListWithoutDuplicate);
}
return interfaceMapWithoutDuplicate;
}
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| Like Feedback map map of list of objects remove duplicates from map Map.Entry |
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| Sample 4. Write a Program for Graph Breadth First Traversal using Apache Commons MultiMap | |
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import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;
public class Graph {
private static Multimap<Integer,Integer> adjacentDirectedNodesMap = ArrayListMultimap.create();
private static Set<Integer> alreadyVisited = new HashSet();
static{
adjacentDirectedNodesMap.put(1, 2);
adjacentDirectedNodesMap.put(1, 3);
adjacentDirectedNodesMap.put(1, 5);
adjacentDirectedNodesMap.put(2, 4);
adjacentDirectedNodesMap.put(4, 5);
}
public static void main(String[] args){
ArrayList visited = new ArrayList();
Integer startNode = 1;
displayAdjacentNodes(startNode);
}
private static void displayAdjacentNodes(Integer integer){
System.out.println(integer);
for(Map.Entry<Integer, Collection<Integer>> adjacentNodes: adjacentDirectedNodesMap.asMap().entrySet()){
for(Integer integer1:adjacentNodes.getValue()){
if(alreadyVisited.contains(integer1)){
continue;
}
alreadyVisited.add(integer1);
System.out.println(integer1);
}
}
}
}
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| Like Feedback graph traversal breadth first traversal |
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| Sample 5. Create a Map using Set elements using Lambda Expression | |
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// Declare and Initialize the Collection
Set<Integer> intSet = new HashSet<Integer>();
// Add Elements
intSet.add(1);
intSet.add(2);
intSet.add(3);
intSet.add(4);
// Use the stream and collectors to get a Map out of Set
System.out.println(intSet.stream().collect((Collectors.toMap(p->(Integer)p,q->((Integer)q)*500)))); // Prints {1=500, 2=1000, 3=1500, 4=2000}
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| Like Feedback lambda expression collections set hashset generics stream collectors |
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| Sample 6. Initialize maps through static block | |
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public class CoinChanger {
private static Map<Currency, Integer> cashBox;
private static Map<Currency, Integer> change;
enum Currency {
DOLLAR,QUARTER,DIME,NICKEL,PENNY;
}
static {
cashBox = new TreeMap<Currency, Integer>();
change = new TreeMap<Currency, Integer>();
initializeCashBox();
}
private static void initializeCashBox(){
//set the cash box
cashBox.put(Currency.DOLLAR, 50);
cashBox.put(Currency.QUARTER, 0);
cashBox.put(Currency.DIME, 50);
cashBox.put(Currency.NICKEL, 50);
cashBox.put(Currency.PENNY, 50);
}
}
}
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| Like Feedback static block enum initializing maps initializing treemap |
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| Sample 7. Clear Map entries after expiration time using Apache commons PassiveExpiringMap | |
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PassiveExpiringMap<String,String> cache = new PassiveExpiringMap<String,String>(1000); // Expiration time of 1 sec
cache.put("Key1", "Value1");
System.out.println(cache.containsKey("Key1"));
Thread.sleep(500);
System.out.println(cache.containsKey("Key1"));
Thread.sleep(500);
System.out.println(cache.containsKey("Key1"));
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| Like Feedback expiring cache using map Clear Map entries after expiration time PassiveExpiringMap |
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| Sample 8. Usage of LinkedHashMap | |
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Map<String,String> linkedhashmap = new LinkedHashMap();
linkedhashmap.put("United States", "Washington");
linkedhashmap.put("Canada", "Ottawa");
linkedhashmap.put("Canada", "Ottawa");
linkedhashmap.put("South Africa", "Pretoria");
linkedhashmap.put("South Africa", "Cape Town");
linkedhashmap.put("South Africa", "Bloemfontein");
System.out.println(linkedhashmap); // Duplicates not allowed as it's a Map, Insertion Order as its linked Map
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| Like Feedback LinkedHashMap Map HashMap java.util collections framework |
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| Sample 9. Usage of Apache Commons - HashSetValuedHashMap | |
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SetValuedMap<String,String> setValuedMap = new HashSetValuedHashMap();
setValuedMap.put("United States", "Washington");
setValuedMap.put("Canada", "Ottawa");
setValuedMap.put("Canada", "Ottawa");
setValuedMap.put("South Africa", "Pretoria");
setValuedMap.put("South Africa", "Cape Town");
setValuedMap.put("South Africa", "Bloemfontein");
System.out.println(setValuedMap); // Values being added to the Set and hence doesn't allow duplicates
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| Like Feedback apache commons apache commons collections apache commons map HashSetValuedHashMap SetValuedMap |
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| Sample 10. Write a Program for Graph Depth First Traversal using Apache Commons MultiMap | |
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import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;
public class Graph {
private static Multimap<Integer,Integer> adjacentDirectedNodesMap = ArrayListMultimap.create();
private static Set<Integer> alreadyVisited = new HashSet();
static{
adjacentDirectedNodesMap.put(1, 2);
adjacentDirectedNodesMap.put(1, 3);
adjacentDirectedNodesMap.put(1, 5);
adjacentDirectedNodesMap.put(2, 4);
adjacentDirectedNodesMap.put(4, 5);
}
public static void main(String[] args){
ArrayList visited = new ArrayList();
Integer startNode = 1;
displayAdjacentNodes(startNode);
}
private static void displayAdjacentNodes(Integer integer){
if(alreadyVisited.contains(integer)){
return;
}
alreadyVisited.add(integer);
System.out.println(integer);
for(Integer adjacentNodes: adjacentDirectedNodesMap.get(integer)){
displayAdjacentNodes(adjacentNodes);
}
}
}
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| Like Feedback graph traversal depth first algorithm |
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| Sample 11. Usage of HashMap | |
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Map<Integer,String> indexedInfo = new HashMap();
indexedInfo.put(1,"Spain");
indexedInfo.put(2,"Denmark");
indexedInfo.put(3,"China");
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| Like Feedback hashmap map collections java.util.hashmap |
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| Sample 12. Method to get a map of words and their count by passing in the string | |
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Map<String,Integer> wordCountMap = new TreeMap();
String[] words = text.split(" ");
Set<Integer> countSet;
for(String word: words) {
if(wordCountMap.containsKey(word.toLowerCase())){
wordCountMap.put(word.toLowerCase(), wordCountMap.get(word.toLowerCase()).intValue() + 1);
} else {
wordCountMap.put(word.toLowerCase(), 1);
}
}
countSet = new TreeSet(Collections.reverseOrder());
countSet.addAll(wordCountMap.values());
for(Integer inte: countSet) {
for(Entry<String,Integer> entry: wordCountMap.entrySet()){
if(entry.getValue() == inte) {
System.out.println(entry);
}
}
}
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| Like Feedback map word count map of string and integer containsKey string split treeset Collections.reverseOrder set addAll entry |
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| Sample 13. Controller in Spring MVC | |
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@Controller
@RequestMapping("/employee")
public class EmployeeInfoController {
@RequestMapping(value = "", method = RequestMethod.GET)
public Model searchEmployeeInfo(Model model, @RequestParam("id") String employeeId) {
// body
}
}
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| Like Feedback controller @Controller @RequestMapping RequestMethod.GET @RequestParam Spring mvc spring framework |
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| Sample 14. Initialize member elements ( maps ) using constructor | |
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public class CoinChanger {
private static Map<Currency, Integer> cashBox;
private static Map<Currency, Integer> change;
enum Currency {
DOLLAR,QUARTER,DIME,NICKEL,PENNY;
}
CoinChanger() {
cashBox = new TreeMap<Currency, Integer>();
change = new TreeMap<Currency, Integer>();
initializeCashBox();
}
private static void initializeCashBox(){
//set the cash box
cashBox.put(Currency.DOLLAR, 50);
cashBox.put(Currency.QUARTER, 0);
cashBox.put(Currency.DIME, 50);
cashBox.put(Currency.NICKEL, 50);
cashBox.put(Currency.PENNY, 50);
}
}
}
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| Like Feedback constructor initializing maps initializing treemap enum |
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| Sample 15. Loading Cache Map using Google Guava LoadingCache and CacheBuilder | |
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LoadingCache<String,String> loadingCache = CacheBuilder.newBuilder().maximumSize(100).expireAfterWrite(1, TimeUnit.MINUTES).build(new CacheLoader<String,String>(){
@Override
public String load(String arg0) throws Exception {
return "";
}
});
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| Like Feedback google guava loadingcache CacheBuilder CacheLoader |
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| Sample 16. Java 8 Map Merge Example ( Map.merge ) | |
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Map<String,String> intMap = new HashMap<String,String>();
strMap.put("Key1","Value1");
strMap.put("Key2", "Value2");
String str = strMap.merge("Key1","Value56",(v1,v2)->v1.substring(3).concat(v2));
System.out.println(str); // prints ue1Value56
System.out.println(strMap); // prints {Key2=Value2, Key1=ue1Value56}
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| Like Feedback java 8 map.merge map merge hashmap collections |
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| Sample 17. Java 8 MapMerge | |
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Map<String,String> strMap = new HashMap<String,String>();
strMap.put("Key1","Value1");
strMap.put("Key2", "Value2");
String str = strMap.merge("Key4","Value56",(v1,v2)->v1.substring(3).concat(v2));
System.out.println(str); // prints Value56
System.out.println(strMap); // prints {Key2=Value2, Key1=Value1, Key4=Value56}
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| Like Feedback java 8 map.merge map merge hashmap collections |
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| Sample 18. Clear Map entries after expiration time using Apache commons PassiveExpiringMap | |
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PassiveExpiringMap<String,String> cache = new PassiveExpiringMap<String,String>(1,TimeUnit.SECONDS); // Expiration time of 1 sec
cache.put("Key1", "Value1");
System.out.println(cache.containsKey("Key1")); // prints true
Thread.sleep(1000);
System.out.println(cache.containsKey("Key1")); // prints false
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| Like Feedback Clear Map entries after expiration PassiveExpiringMap map apache commons TimeUnit.SECONDS Thread.sleep |
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| Sample 19. Make a map readonly using Apache Commons UnmodifiableMap | |
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Map<String,String> map = new HashMap();
map.put("Key1", "Value1");
Map<String,String> unmodifiableMap = UnmodifiableMap.unmodifiableMap(map);
unmodifiableMap.put("Key2", "Value2"); // throws java.lang.UnsupportedOperationException
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| Like Feedback readonly map apache commons |
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| Sample 20. Make a Map entry read only using Apache Commons UnmodifiableMapEntry | |
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Entry entry = new UnmodifiableMapEntry("Key2", "Value2");
entry.setValue("Value3"); // throws java.lang.UnsupportedOperationException
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| Like Feedback read only map entry UnmodifiableMapEntry Apache commons collections |
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| Sample 21. Usage of TreeMap | |
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Map<String,String> treemap = new TreeMap();
treemap.put("United States", "Washington");
treemap.put("Canada", "Ottawa");
treemap.put("Canada", "Ottawa");
treemap.put("South Africa", "Pretoria");
treemap.put("South Africa", "Cape Town");
treemap.put("South Africa", "Bloemfontein");
System.out.println(treemap); // Duplicate Not allowed as it's a Map, Ordered by Keys as it's a TreeMap
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| Like Feedback TreeMap Map java.util |
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| Sample 22. Print all elements of a ListValuedMap ( Apache Commons ) using forEach and System.out::println | |
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ListValuedMap<String,String> listValuedMap = new ArrayListValuedHashMap();
listValuedMap.put("United States", "Washington");
listValuedMap.put("Canada", "Ottawa");
listValuedMap.put("Canada", "Ottawa");
listValuedMap.put("South Africa", "Pretoria");
listValuedMap.put("South Africa", "Cape Town");
listValuedMap.put("South Africa", "Bloemfontein");
listValuedMap.entries().forEach(System.out::println);
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| Like Feedback ListValuedMap apache commons System.out::println collections framework map |
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| Sample 23. Usage of ConcurrentSkipListMap | |
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Map<String,String> map = new ConcurrentSkipListMap();
map.put("United States", "Washington");
map.put("Canada", "Ottawa");
map.put("Canada", "Ottawa");
map.put("South Africa", "Pretoria");
map.put("South Africa", "Cape Town");
map.put("South Africa", "Bloemfontein");
System.out.println(map); // Prints {Canada=Ottawa, South Africa=Bloemfontein, United States=Washington}
// Duplicates not allowed as it's a Map, Sorted as par natural order of keys for faster and concurrent operations.
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| Like Feedback map ConcurrentSkipListMap concurrent access map |
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| Sample 24. Usage of EnumMap | |
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Map<Country,String> map = new HashMap();
map.put(Country.US, "Washington");
map.put(Country.CANADA, "Ottawa");
map.put(Country.CANADA, "Ottawa");
map.put(Country.SOUTH_AFRICA, "Pretoria");
map.put(Country.SOUTH_AFRICA, "Cape Town");
map.put(Country.SOUTH_AFRICA, "Bloemfontein");
Map<String,String> enumMap = new EnumMap(map); // Prints {CANADA=Ottawa, US=Washington, SOUTH_AFRICA=Bloemfontein}
System.out.println(enumMap); // Duplicates not allowed as it's a Map, Sorted as per order of Enum Declarations
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| Like Feedback EnumMap Collections framework Map Map with enum keys |
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| Sample 25. Usage of Apache Commons CaseInsensitiveMap | |
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Map<String, String> map = new CaseInsensitiveMap<String, String>();
map.put("US", "Washington");
map.put("us", "Washington DC");
System.out.println(map); // Prints {us=Washington DC} as Keys are case insensitive
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| Like Feedback CaseInsensitiveMap Map with Case insensitive keys apache commons apache commons collections |
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| Sample 26. Code Sample / Example / Snippet of org.apache.hadoop.mapred.TaskTracker.TaskInProgress | |
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public synchronized boolean statusUpdate(TaskAttemptID taskid,
TaskStatus taskStatus)
throws IOException {
TaskInProgress tip = tasks.get(taskid);
if (tip != null) {
tip.reportProgress(taskStatus);
return true;
} else {
LOG.warn("Progress from unknown child task: "+taskid);
return false;
}
}
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| Like Feedback org.apache.hadoop.mapred.TaskTracker.TaskInProgress |
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| Sample 27. Code Sample / Example / Snippet of org.apache.hadoop.mapred.Counters.Counter | |
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public synchronized void incrAllCounters(Counters other) {
for (Group otherGroup: other) {
Group group = getGroup(otherGroup.getName());
group.displayName = otherGroup.displayName;
for (Counter otherCounter : otherGroup) {
Counter counter = group.getCounterForName(otherCounter.getName());
counter.displayName = otherCounter.displayName;
counter.value += otherCounter.value;
}
}
}
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| Like Feedback org.apache.hadoop.mapred.Counters.Counter |
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| Sample 28. Code Sample / Example / Snippet of org.apache.hadoop.mapred.Mapper | |
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public void map(Object key, Object value, OutputCollector output,
Reporter reporter) throws IOException {
Mapper mapper = chain.getFirstMap();
if (mapper != null) {
mapper.map(key, value, chain.getMapperCollector(0, output, reporter),
reporter);
}
}
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| Like Feedback org.apache.hadoop.mapred.Mapper |
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| Sample 29. Code Sample / Example / Snippet of org.apache.hadoop.mapred.lib.KeyFieldHelper.KeyDescription | |
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public void setKeyFieldSpec(int start, int end) {
if (end >= start) {
KeyDescription k = new KeyDescription();
k.beginFieldIdx = start;
k.endFieldIdx = end;
keySpecSeen = true;
allKeySpecs.add(k);
}
}
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| Like Feedback org.apache.hadoop.mapred.lib.KeyFieldHelper.KeyDescription |
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| Sample 30. Code Sample / Example / Snippet of java.util.Map | |
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public Schema create(SchemaPlus parentSchema, String name,
Map<String, Object> operand) {
Map map = (Map) operand;
String host = (String) map.get("host");
String database = (String) map.get("database");
return new MongoSchema(host, database);
}
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| Like Feedback java.util.Map |
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| Sample 31. Code Sample / Example / Snippet of com.fasterxml.jackson.databind.ObjectMapper | |
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public JsonEnumerator(File file) {
try {
final ObjectMapper mapper = new ObjectMapper();
mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
mapper.configure(JsonParser.Feature.ALLOW_COMMENTS, true);
List<Object> list = mapper.readValue(file, List.class);
enumerator = Linq4j.enumerator(list);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
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| Like Feedback com.fasterxml.jackson.databind.ObjectMapper |
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| Sample 32. Code Sample / Example / Snippet of org.apache.calcite.schema.SchemaPlus | |
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public Connection apply(Connection connection) throws SQLException {
if (schema != null) {
CalciteConnection con = connection.unwrap(CalciteConnection.class);
SchemaPlus rootSchema = con.getRootSchema();
rootSchema.add(name, schema);
}
connection.setSchema(name);
return connection;
}
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| Like Feedback org.apache.calcite.schema.SchemaPlus |
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| Sample 33. Code Sample / Example / Snippet of org.apache.hc.core5.http.impl.nio.UriHttpAsyncRequestHandlerMapper | |
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public void testRegisterUnregister() throws Exception {
final HttpAsyncRequestHandler<?> h = Mockito.mock(HttpAsyncRequestHandler.class);
final UriPatternMatcher<HttpAsyncRequestHandler<?>> matcher = Mockito.spy(
new UriPatternMatcher<HttpAsyncRequestHandler<?>>());
final UriHttpAsyncRequestHandlerMapper registry = new UriHttpAsyncRequestHandlerMapper(matcher);
registry.register("/h1", h);
registry.unregister("/h1");
Mockito.verify(matcher).register("/h1", h);
Mockito.verify(matcher).unregister("/h1");
}
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| Like Feedback org.apache.hc.core5.http.impl.nio.UriHttpAsyncRequestHandlerMapper |
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| Sample 34. Code Sample / Example / Snippet of java.util.concurrent.Semaphore | |
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private void removeRepository(String instanceName) throws IOException, InterruptedException, InvalidSyntaxException {
Configuration[] configs = listConfigurations("(factory.instance.pid=" + instanceName + ")");
if ((configs != null) && (configs.length > 0)) {
final Semaphore sem = new Semaphore(0);
ServiceTracker<Object, Object> tracker = new ServiceTracker<Object, Object>(m_bundleContext, m_bundleContext.createFilter("(factory.instance.pid=" + instanceName + ")"), null) {
@Override
public void removedService(ServiceReference<Object> reference, Object service) {
super.removedService(reference, service);
sem.release();
}
};
tracker.open();
try {
configs[0].delete();
if (!sem.tryAcquire(1, TimeUnit.SECONDS)) {
throw new IOException("Instance did not get removed in time.");
}
}
finally {
tracker.close();
}
}
}
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| Like Feedback java.util.concurrent.Semaphore |
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| Sample 35. Code Sample / Example / Snippet of org.apache.bcel.classfile.StackMap | |
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public Attribute copy( final ConstantPool _constant_pool ) {
final StackMap c = (StackMap) clone();
c.map = new StackMapEntry[map.length];
for (int i = 0; i < map.length; i++) {
c.map[i] = map[i].copy();
}
c.setConstantPool(_constant_pool);
return c;
}
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| Like Feedback org.apache.bcel.classfile.StackMap |
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| Sample 36. Hibernate - Mapping the Id to RowId of Table ( workaround for Table having no primary key ) | |
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@Id
@Column(name="ROWID")
private String id;
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| Like Feedback Hibernate workaround for Table having no primary key mapping Id to RowId |
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| Sample 37. Usage of java.util.stream.Stream | |
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List<Integer> list1 = Arrays.asList(1, 2);
List<Integer> list2 = Arrays.asList(4, 5);
Stream.of(list1, list1)
.flatMap(list -> list.stream())
.forEach(System.out::println);
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| Like Feedback Stream.flatMap System.out::println |
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Sample 38. Initializing a map using factory method in java 9
Usage of Map.of() | |
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Map<String,String> countryCodeMap = Map.of("France","FR","United States","US","Canada","CA");
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| Like Feedback java 9 |
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