Move page object creation to PageResult class

scm-core/src/main/java/sonia/scm/Manager.java

@@ -33,14 +33,10 @@
 
 package sonia.scm;
 
-import sonia.scm.util.Util;
-
 import java.io.IOException;
 import java.util.Collection;
 import java.util.Comparator;
 
-import static com.google.common.base.Preconditions.checkArgument;
-
 /**
  * Base interface for all manager classes.
  *
@@ -141,14 +137,7 @@ public interface Manager<T extends ModelObject, E extends Exception>
    *         empty page result is returned.
    */
   default PageResult<T> getPage(Comparator<T> comparator, int pageNumber, int pageSize) {
-    checkArgument(pageSize > 0, "pageSize must be at least 1");
+    return PageResult.createPage(getAll(comparator), pageNumber, pageSize);
-    checkArgument(pageNumber >= 0, "pageNumber must be non-negative");
-
-    Collection<T> allEntities = getAll(comparator);
-
-    Collection<T> pagedEntities = Util.createSubCollection(allEntities, pageNumber * pageSize, pageSize);
-
-    return new PageResult<>(pagedEntities, allEntities.size());
   }
 
 }

scm-core/src/main/java/sonia/scm/PageResult.java

@@ -3,6 +3,9 @@ package sonia.scm;
 import java.util.Collection;
 import java.util.Collections;
 
+import static com.google.common.base.Preconditions.checkArgument;
+import static sonia.scm.util.Util.createSubCollection;
+
 /**
  * This represents the result of a page request. Contains the results for
  * the page and the overall count of all elements.
@@ -12,6 +15,15 @@ public class PageResult<T extends ModelObject> {
   private final Collection<T> entities;
   private final int overallCount;
 
+  public static <T extends ModelObject> PageResult<T> createPage(Collection<T> allEntities, int pageNumber, int pageSize) {
+    checkArgument(pageSize > 0, "pageSize must be at least 1");
+    checkArgument(pageNumber >= 0, "pageNumber must be non-negative");
+
+    Collection<T> pagedEntities = createSubCollection(allEntities, pageNumber * pageSize, pageSize);
+
+    return new PageResult<>(pagedEntities, allEntities.size());
+  }
+
   public PageResult(Collection<T> entities, int overallCount) {
     this.entities = entities;
     this.overallCount = overallCount;

scm-webapp/src/test/java/sonia/scm/api/v2/resources/GroupCollectionToDtoMapperTest.java

@@ -24,6 +24,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
+import static sonia.scm.PageResult.createPage;
 
 public class GroupCollectionToDtoMapperTest {
 
@@ -68,9 +69,7 @@ public class GroupCollectionToDtoMapperTest {
 
   @Test
   public void shouldCreateNextPageLink_whenHasMore() {
-    PageResult<Group> intermediate = mockPageResult("nobodies");
+    PageResult<Group> pageResult = createPage(createGroups("nobodies", "bosses"), 0, 1);
-    PageResult<Group> pageResult = new PageResult<>(intermediate.getEntities(), 2);
-
     GroupCollectionDto groupCollectionDto = mapper.map(1, 1, pageResult);
     assertTrue(groupCollectionDto.getLinks().getLinkBy("next").get().getHref().contains("page=2"));
   }
@@ -113,10 +112,14 @@ public class GroupCollectionToDtoMapperTest {
   }
 
   private PageResult<Group> mockPageResult(String... groupNames) {
-    Collection<Group> groups = Arrays.stream(groupNames).map(this::mockGroupWithDto).collect(toList());
+    Collection<Group> groups = createGroups(groupNames);
     return new PageResult<>(groups, groups.size());
   }
 
+  private List<Group> createGroups(String... groupNames) {
+    return Arrays.stream(groupNames).map(this::mockGroupWithDto).collect(toList());
+  }
+
   private Group mockGroupWithDto(String groupName) {
     Group group = new Group();
     group.setName(groupName);

scm-webapp/src/test/java/sonia/scm/api/v2/resources/UserCollectionToDtoMapperTest.java

@@ -16,7 +16,6 @@ import javax.ws.rs.core.UriInfo;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.List;
 
 import static java.util.stream.Collectors.toList;
@@ -25,6 +24,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.when;
 import static org.mockito.MockitoAnnotations.initMocks;
+import static sonia.scm.PageResult.createPage;
 
 public class UserCollectionToDtoMapperTest {
 
@@ -76,8 +76,7 @@ public class UserCollectionToDtoMapperTest {
 
   @Test
   public void shouldCreateNextPageLink_whenHasMore() {
-    PageResult<User> intermediate = mockPageResult("Hannes");
+    PageResult<User> pageResult = createPage(createUsers("Hannes", "Karl"), 0, 1);
-    PageResult<User> pageResult = new PageResult<>(intermediate.getEntities(), 2);
 
     UserCollectionDto userCollectionDto = mapper.map(1, 1, pageResult);
     assertTrue(userCollectionDto.getLinks().getLinkBy("next").get().getHref().contains("page=2"));
@@ -121,8 +120,11 @@ public class UserCollectionToDtoMapperTest {
   }
 
   private PageResult<User> mockPageResult(String... userNames) {
-    Collection<User> users = Arrays.stream(userNames).map(this::mockUserWithDto).collect(toList());
+    return createPage(createUsers(userNames), 0, userNames.length);
-    return new PageResult<>(users, users.size());
+  }
+
+  private List<User> createUsers(String... userNames) {
+    return Arrays.stream(userNames).map(this::mockUserWithDto).collect(toList());
   }
 
   private User mockUserWithDto(String userName) {