@@ -5,6 +5,25 @@
 */
 package org.springdoc.demo.app2.api;
 
+import java.util.List;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotNull;
+
+import org.springdoc.demo.app2.model.ModelApiResponse;
+import org.springdoc.demo.app2.model.Pet;
+import org.springframework.data.domain.Pageable;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RequestPart;
+import org.springframework.web.multipart.MultipartFile;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.enums.Explode;
@@ -135,4 +154,14 @@ default ResponseEntity<ModelApiResponse> uploadFile(
 return getDelegate().uploadFile(petId, additionalMetadata, file);
 }
 
+@Operation(summary = "Get all Pets paged", description = "Get all Pets paged", security = {
+@SecurityRequirement(name = "petstore_auth", scopes = { "write:pets", "read:pets" }) }, tags = { "pet" })
+@ApiResponses(value = {
+@ApiResponse(responseCode = "200", description = "successful operation", content = @Content(array = @ArraySchema(schema = @Schema(implementation = Pet.class))))
+})
+@GetMapping(value = "/pet", produces = { "application/xml", "application/json" })
+default ResponseEntity<List<Pet>> getAllPets(@NotNull Pageable pageable) {
+return getDelegate().getAllPets(pageable);
+}
+
 }

@@ -1,7 +1,13 @@
 package org.springdoc.demo.app2.api;
 
+import java.util.List;
+import java.util.Optional;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotNull;
 import org.springdoc.demo.app2.model.ModelApiResponse;
 import org.springdoc.demo.app2.model.Pet;
+import org.springframework.data.domain.Pageable;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
@@ -118,4 +124,8 @@ default ResponseEntity<ModelApiResponse> uploadFile( Long petId,
 
 }
 
+default ResponseEntity<List<Pet>> getAllPets(@NotNull Pageable pageable) {
+return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
+}
+
 }

@@ -1,11 +1,23 @@
 package org.springdoc.demo.app2.api;
 
+import java.io.File;
+import java.io.FileOutputStream;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Collectors;
+
+import javax.annotation.PostConstruct;
+import javax.validation.constraints.NotNull;
+
 import org.apache.tomcat.util.http.fileupload.IOUtils;
 import org.springdoc.demo.app2.model.Category;
 import org.springdoc.demo.app2.model.ModelApiResponse;
 import org.springdoc.demo.app2.model.Pet;
 import org.springdoc.demo.app2.model.Tag;
 import org.springdoc.demo.app2.repository.PetRepository;
+import org.springframework.data.domain.Pageable;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
@@ -147,4 +159,9 @@ private static Pet createPet(long id, Category category, String name, String[] u
 return pet;
 }
 
+public ResponseEntity<List<Pet>> getAllPets(@NotNull Pageable pageable) {
+ApiUtil.checkApiKey(request);
+return new ResponseEntity<List<Pet>>(petRepository.findAll(pageable), HttpStatus.OK);
+}
+
 }

@@ -1,9 +1,15 @@
 package org.springdoc.demo.app2.repository;
 
+import org.springframework.beans.BeanWrapper;
+import org.springframework.beans.BeanWrapperImpl;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.NoRepositoryBean;
 import org.springframework.util.Assert;
 
+import java.beans.BeanInfo;
+import java.beans.PropertyDescriptor;
 import java.util.*;
 
 @NoRepositoryBean
@@ -13,6 +19,12 @@ public abstract class HashMapRepository<T, ID> implements CrudRepository<T, ID>
 
 abstract <S extends T> ID getEntityId(S entity);
 
+private final BeanWrapper entityBeanInfo;
+
+protected HashMapRepository(Class<T> clazz) {
+entityBeanInfo = new BeanWrapperImpl(clazz);
+}
+
 @Override
 public <S extends T> S save(S entity) {
 Assert.notNull(entity, "entity cannot be null");
@@ -34,6 +46,58 @@ public Collection<T> findAll() {
 return entities.values();
 }
 
+public List<T> findAll(Pageable pageable) {
+final List<T> result;
+final Sort sort = pageable.getSort();
+if (sort != null) {
+Comparator<T> comp = new Comparator<T>() {
+@Override
+public int compare(T t1, T t2) {
+int result = 0;
+for (Sort.Order o : sort) {
+final String prop = o.getProperty();
+PropertyDescriptor propDesc = entityBeanInfo.getPropertyDescriptor(prop);
+result = ((Comparable<T>) propDesc.createPropertyEditor(t1).getValue())
+.compareTo((T) propDesc.createPropertyEditor(t2).getValue());
+if (o.isDescending()) {
+result = -result;
+}
+if (result != 0) break;
+}
+return result;
+}
+};
+final Set<T> set = new TreeSet<>(comp);
+set.addAll(entities.values());
+result = getPageSlice(pageable, set);
+} else {
+result = getPageSlice(pageable, entities.values());
+}
+return result;
+}
+
+private List<T> getPageSlice(Pageable pageable, Collection<T> col) {
+final ArrayList<T> all = new ArrayList<>(col);
+final int size = all.size();
+final int psize = pageable.getPageSize();
+final int pnum = pageable.getPageNumber();
+if (pnum < 1) {
+throw new IllegalArgumentException("page number must be 1 or more");
+}
+if (psize < 1) {
+throw new IllegalArgumentException("page size must be 1 or more");
+}
+// inclusive
+final int begin = (pnum - 1) * psize;
+// exclusive
+final int end = Math.min(begin + psize, size);
+if (size < begin) {
+return new ArrayList<>();
+}
+// return of slice is valid because all is local to this method
+return all.subList(begin, end);
+}
+
 @Override
 public long count() {
 return entities.keySet().size();

@@ -6,6 +6,10 @@
 @Repository
 public class OrderRepository extends HashMapRepository<Order, Long> {
 
+public OrderRepository() {
+super(Order.class);
+}
+
 @Override
 <S extends Order> Long getEntityId(S order) {
 return order.getId();

@@ -12,6 +12,10 @@ public class PetRepository extends HashMapRepository<Pet, Long> {
 
 private Long sequenceId = 1L;
 
+public PetRepository() {
+super(Pet.class);
+}
+
 @Override
 <S extends Pet> Long getEntityId(S pet) {
 return pet.getId();

@@ -6,6 +6,10 @@
 @Repository
 public class UserRepository extends HashMapRepository<User, String> {
 
+public UserRepository() {
+super(User.class);
+}
+
 @Override
 <S extends User> String getEntityId(S user) {
 return user.getUsername();