Merge pull request #432 from PriyaKrishna/master
Core java enum examples
This commit is contained in:
Alex Theedom
commit
c8a8132d06
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package com.baeldung.enums;
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import java.util.EnumMap;
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import java.util.EnumSet;
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import java.util.List;
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import java.util.stream.Collectors;
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public class Pizza {
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private static EnumSet<PizzaStatusEnum> deliveredPizzaStatuses =
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EnumSet.of(PizzaStatusEnum.DELIVERED);
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private PizzaStatusEnum status;
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public enum PizzaStatusEnum {
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ORDERED (5){
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@Override
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public boolean isOrdered() {
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return true;
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}
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},
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READY (2){
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@Override
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public boolean isReady() {
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return true;
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}
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},
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DELIVERED (0){
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@Override
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public boolean isDelivered() {
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return true;
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}
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};
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private int timeToDelivery;
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public boolean isOrdered() {return false;}
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public boolean isReady() {return false;}
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public boolean isDelivered(){return false;}
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public int getTimeToDelivery() {
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return timeToDelivery;
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}
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private PizzaStatusEnum (int timeToDelivery) {
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this.timeToDelivery = timeToDelivery;
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}
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}
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public PizzaStatusEnum getStatus() {
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return status;
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}
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public void setStatus(PizzaStatusEnum status) {
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this.status = status;
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}
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public boolean isDeliverable() {
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return this.status.isReady();
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}
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public void printTimeToDeliver() {
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System.out.println("Time to delivery is " + this.getStatus().getTimeToDelivery() + " days");
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}
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public static List<Pizza> getAllUndeliveredPizzas(List<Pizza> input) {
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return input.stream().filter((s) -> !deliveredPizzaStatuses.contains(s.getStatus())).collect(Collectors.toList());
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}
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public static EnumMap<PizzaStatusEnum, List<Pizza>> groupPizzaByStatus(List<Pizza> pzList) {
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EnumMap<PizzaStatusEnum, List<Pizza>> map = pzList.stream().collect(
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Collectors.groupingBy(Pizza::getStatus,
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() -> new EnumMap<PizzaStatusEnum, List<Pizza>>(PizzaStatusEnum.class), Collectors.toList()));
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return map;
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}
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public void deliver() {
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if (isDeliverable()) {
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PizzaDeliverySystemConfiguration.getInstance().getDeliveryStrategy().deliver(this);
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this.setStatus(PizzaStatusEnum.DELIVERED);
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}
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}
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}
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@ -0,0 +1,18 @@
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package com.baeldung.enums;
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public enum PizzaDeliveryStrategy {
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EXPRESS {
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@Override
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public void deliver(Pizza pz) {
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System.out.println("Pizza will be delivered in express mode");
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}
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},
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NORMAL {
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@Override
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public void deliver(Pizza pz) {
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System.out.println("Pizza will be delivered in normal mode");
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}
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};
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public abstract void deliver(Pizza pz);
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}
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@ -0,0 +1,21 @@
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package com.baeldung.enums;
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public enum PizzaDeliverySystemConfiguration {
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INSTANCE ;
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private PizzaDeliverySystemConfiguration() {
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//Do the configuration initialization which
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// involves overriding defaults like delivery strategy
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}
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private PizzaDeliveryStrategy deliveryStrategy = PizzaDeliveryStrategy.NORMAL;
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public static PizzaDeliverySystemConfiguration getInstance() {
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return INSTANCE;
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}
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public PizzaDeliveryStrategy getDeliveryStrategy() {
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return deliveryStrategy;
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}
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}
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@ -0,0 +1,78 @@
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package com.baeldung.enums;
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import org.junit.Test;
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import java.util.ArrayList;
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import java.util.EnumMap;
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import java.util.List;
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import static junit.framework.TestCase.assertTrue;
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public class PizzaTest {
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@Test
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public void givenPizaOrder_whenReady_thenDeliverable() {
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Pizza testPz = new Pizza();
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testPz.setStatus(Pizza.PizzaStatusEnum.READY);
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assertTrue(testPz.isDeliverable());
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}
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@Test
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public void givenPizaOrders_whenRetrievingUnDeliveredPzs_thenCorrectlyRetrieved() {
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List<Pizza> pzList = new ArrayList<Pizza>();
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Pizza pz1 = new Pizza();
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pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
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Pizza pz2 = new Pizza();
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pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz3 = new Pizza();
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pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz4 = new Pizza();
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pz4.setStatus(Pizza.PizzaStatusEnum.READY);
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pzList.add(pz1);
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pzList.add(pz2);
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pzList.add(pz3);
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pzList.add(pz4);
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List<Pizza> undeliveredPzs = Pizza.getAllUndeliveredPizzas(pzList);
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assertTrue(undeliveredPzs.size() == 3);
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}
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@Test
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public void givenPizaOrders_whenGroupByStatusCalled_thenCorrectlyGrouped() {
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List<Pizza> pzList = new ArrayList<Pizza>();
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Pizza pz1 = new Pizza();
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pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
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Pizza pz2 = new Pizza();
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pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz3 = new Pizza();
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pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz4 = new Pizza();
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pz4.setStatus(Pizza.PizzaStatusEnum.READY);
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pzList.add(pz1);
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pzList.add(pz2);
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pzList.add(pz3);
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pzList.add(pz4);
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EnumMap<Pizza.PizzaStatusEnum, List<Pizza>> map = Pizza.groupPizzaByStatus(pzList);
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assertTrue(map.get(Pizza.PizzaStatusEnum.DELIVERED).size() == 1);
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assertTrue(map.get(Pizza.PizzaStatusEnum.ORDERED).size() == 2);
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assertTrue(map.get(Pizza.PizzaStatusEnum.READY).size() == 1);
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}
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@Test
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public void givenPizaOrder_whenDelivered_thenPizzaGetsDeliveredAndStatusChanges() {
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Pizza pz = new Pizza();
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pz.setStatus(Pizza.PizzaStatusEnum.READY);
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pz.deliver();
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assertTrue(pz.getStatus() == Pizza.PizzaStatusEnum.DELIVERED);
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}
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}
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@ -9,7 +9,11 @@
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<dependencies>
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<!-- utils -->
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<dependency>
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<groupId>net.sourceforge.collections</groupId>
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<artifactId>collections-generic</artifactId>
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<version>4.01</version>
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</dependency>
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<dependency>
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<groupId>com.google.guava</groupId>
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<artifactId>guava</artifactId>
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@ -0,0 +1,117 @@
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package com.baeldung.enums;
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import com.fasterxml.jackson.annotation.JsonFormat;
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import com.fasterxml.jackson.annotation.JsonProperty;
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import com.fasterxml.jackson.databind.ObjectMapper;
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import org.apache.commons.collections15.CollectionUtils;
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import org.apache.commons.collections15.Predicate;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.EnumMap;
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import java.util.EnumSet;
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import java.util.List;
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public class Pizza {
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private static EnumSet<PizzaStatusEnum> undeliveredPizzaStatuses =
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EnumSet.of(PizzaStatusEnum.ORDERED, PizzaStatusEnum.READY);
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private PizzaStatusEnum status;
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@JsonFormat(shape = JsonFormat.Shape.OBJECT)
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public enum PizzaStatusEnum {
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ORDERED (5){
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@Override
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public boolean isOrdered() {
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return true;
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}
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},
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READY (2){
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@Override
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public boolean isReady() {
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return true;
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}
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},
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DELIVERED (0){
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@Override
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public boolean isDelivered() {
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return true;
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}
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};
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private int timeToDelivery;
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public boolean isOrdered() {return false;}
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public boolean isReady() {return false;}
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public boolean isDelivered(){return false;}
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@JsonProperty("timeToDelivery")
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public int getTimeToDelivery() {
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return timeToDelivery;
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}
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private PizzaStatusEnum (int timeToDelivery) {
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this.timeToDelivery = timeToDelivery;
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}
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}
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public PizzaStatusEnum getStatus() {
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return status;
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}
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public void setStatus(PizzaStatusEnum status) {
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this.status = status;
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}
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public boolean isDeliverable() {
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return this.status.isReady();
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}
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public void printTimeToDeliver() {
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System.out.println("Time to delivery is " + this.getStatus().getTimeToDelivery() + " days");
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}
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public static List<Pizza> getAllUndeliveredPizza(List<Pizza> input) {
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List<Pizza> undelivered = input;
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CollectionUtils.filter(undelivered, thatAreNotDelivered());
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return undelivered;
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}
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public static EnumMap<PizzaStatusEnum, List<Pizza>> groupPizzaByStatus(List<Pizza> pizzaList) {
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EnumMap<PizzaStatusEnum, List<Pizza>> pzByStatus = new EnumMap<PizzaStatusEnum, List<Pizza>>(PizzaStatusEnum.class);
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for (Pizza pz : pizzaList) {
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PizzaStatusEnum status = pz.getStatus();
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if (pzByStatus.containsKey(status)) {
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pzByStatus.get(status).add(pz);
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} else {
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List<Pizza> newPzList = new ArrayList<Pizza>();
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newPzList.add(pz);
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pzByStatus.put(status, newPzList);
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}
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}
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return pzByStatus;
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}
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public void deliver() {
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if (isDeliverable()) {
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PizzaDeliverySystemConfiguration.getInstance().getDeliveryStrategy().deliver(this);
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this.setStatus(PizzaStatusEnum.DELIVERED);
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}
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}
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public static String getJsonString(Pizza pz) throws IOException {
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ObjectMapper mapper = new ObjectMapper();
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return mapper.writerWithDefaultPrettyPrinter().writeValueAsString(pz);
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}
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private static Predicate<Pizza> thatAreNotDelivered() {
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return new Predicate<Pizza>() {
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public boolean evaluate(Pizza entry) {
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return undeliveredPizzaStatuses.contains(entry.getStatus());
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}
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};
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}
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}
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@ -0,0 +1,18 @@
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package com.baeldung.enums;
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public enum PizzaDeliveryStrategy {
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EXPRESS {
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@Override
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public void deliver(Pizza pz) {
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System.out.println("Pizza will be delivered in express mode");
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}
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},
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NORMAL {
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@Override
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public void deliver(Pizza pz) {
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System.out.println("Pizza will be delivered in normal mode");
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}
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};
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public abstract void deliver(Pizza pz);
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}
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@ -0,0 +1,20 @@
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package com.baeldung.enums;
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public enum PizzaDeliverySystemConfiguration {
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INSTANCE ;
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private PizzaDeliverySystemConfiguration() {
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//Do the configuration initialization which
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// involves overriding defaults like delivery strategy
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}
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private PizzaDeliveryStrategy deliveryStrategy = PizzaDeliveryStrategy.NORMAL;
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public static PizzaDeliverySystemConfiguration getInstance() {
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return INSTANCE;
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}
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public PizzaDeliveryStrategy getDeliveryStrategy() {
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return deliveryStrategy;
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}
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}
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@ -0,0 +1,80 @@
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package org.baeldung.java.enums;
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import com.baeldung.enums.Pizza;
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import org.junit.Test;
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import java.util.ArrayList;
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import java.util.EnumMap;
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import java.util.List;
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import static junit.framework.TestCase.assertTrue;
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public class PizzaTest {
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@Test
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public void givenPizaOrder_whenReady_thenDeliverable() {
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Pizza testPz = new Pizza();
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testPz.setStatus(Pizza.PizzaStatusEnum.READY);
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assertTrue(testPz.isDeliverable());
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}
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@Test
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public void givenPizaOrders_whenRetrievingUnDeliveredPzs_thenCorrectlyRetrieved() {
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List<Pizza> pzList = new ArrayList<Pizza>();
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Pizza pz1 = new Pizza();
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pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
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Pizza pz2 = new Pizza();
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pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz3 = new Pizza();
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pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz4 = new Pizza();
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pz4.setStatus(Pizza.PizzaStatusEnum.READY);
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pzList.add(pz1);
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pzList.add(pz2);
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pzList.add(pz3);
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pzList.add(pz4);
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List<Pizza> undeliveredPzs = Pizza.getAllUndeliveredPizza(pzList);
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assertTrue(undeliveredPzs.size() == 3);
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}
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@Test
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public void givenPizaOrders_whenGroupByStatusCalled_thenCorrectlyGrouped() {
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List<Pizza> pzList = new ArrayList<Pizza>();
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Pizza pz1 = new Pizza();
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pz1.setStatus(Pizza.PizzaStatusEnum.DELIVERED);
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Pizza pz2 = new Pizza();
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pz2.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz3 = new Pizza();
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pz3.setStatus(Pizza.PizzaStatusEnum.ORDERED);
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Pizza pz4 = new Pizza();
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pz4.setStatus(Pizza.PizzaStatusEnum.READY);
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pzList.add(pz1);
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pzList.add(pz2);
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pzList.add(pz3);
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pzList.add(pz4);
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EnumMap<Pizza.PizzaStatusEnum, List<Pizza>> map = Pizza.groupPizzaByStatus(pzList);
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assertTrue(map.get(Pizza.PizzaStatusEnum.DELIVERED).size() == 1);
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assertTrue(map.get(Pizza.PizzaStatusEnum.ORDERED).size() == 2);
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assertTrue(map.get(Pizza.PizzaStatusEnum.READY).size() == 1);
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}
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@Test
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public void givenPizaOrder_whenDelivered_thenPizzaGetsDeliveredAndStatusChanges() {
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Pizza pz = new Pizza();
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pz.setStatus(Pizza.PizzaStatusEnum.READY);
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pz.deliver();
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assertTrue(pz.getStatus() == Pizza.PizzaStatusEnum.DELIVERED);
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}
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}
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