Fix serialization of Page.empty() (#3142)

* Fix serialization of Page.empty() * Add javadoc comment
micronaut-projects · Sep 24, 2024 · a608ef4 · a608ef4
1 parent af88d15
commit a608ef4
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Showing 3 changed files with 18 additions and 3 deletions.
diff --git a/data-model/src/main/java/io/micronaut/data/model/DefaultPage.java b/data-model/src/main/java/io/micronaut/data/model/DefaultPage.java
@@ -58,7 +58,7 @@ class DefaultPage<T> extends DefaultSlice<T> implements Page<T> {
 
     @Override
     public boolean hasTotalSize() {
-        return totalSize != null;
+        return totalSize != null && totalSize != -1L;
     }
 
     @Override

diff --git a/data-model/src/main/java/io/micronaut/data/model/Page.java b/data-model/src/main/java/io/micronaut/data/model/Page.java
@@ -50,7 +50,7 @@
 @DefaultImplementation(DefaultPage.class)
 public interface Page<T> extends Slice<T> {
 
-    Page<?> EMPTY = new DefaultPage<>(Collections.emptyList(), Pageable.unpaged(), null);
+    Page<?> EMPTY = new DefaultPage<>(Collections.emptyList(), Pageable.unpaged(), -1L);
 
     /**
      * @return Whether this {@link Page} contains the total count of the records
@@ -62,6 +62,7 @@ public interface Page<T> extends Slice<T> {
      * Get the total count of all the records that can be given by this query.
      * The method may produce a {@link IllegalStateException} if the {@link Pageable} request
      * did not ask for total size.
+     * For {@link #EMPTY} page the value is -1.
      *
      * @return The total size of the all records.
      */

diff --git a/data-model/src/test/groovy/io/micronaut/data/model/PageSpec.groovy b/data-model/src/test/groovy/io/micronaut/data/model/PageSpec.groovy
@@ -86,9 +86,16 @@ class PageSpec extends Specification {
         def json = mapper.writeValueAsString(page)
 
         then:
-        def deserializedPage = mapper.readValue(json, mapper.typeFactory.constructParametricType(Page, Dummy))
+        def deserializedPage = (Page<Dummy>) mapper.readValue(json, mapper.typeFactory.constructParametricType(Page, Dummy))
         deserializedPage.content.every { it instanceof Dummy }
         deserializedPage == page
+
+        when:"Serialize and deserialize empty page"
+        json = mapper.writeValueAsString(Page.empty())
+
+        then:"It is done without errors"
+        def deserializedEmptyPage = (Page<Dummy>) mapper.readValue(json, mapper.typeFactory.constructParametricType(Page, Dummy))
+        !deserializedEmptyPage.hasTotalSize()
     }
 
     void "test serialization and deserialization of a page - serde"() {
@@ -113,6 +120,13 @@ class PageSpec extends Specification {
         def deserializedPage = serdeMapper.readValue(json, Argument.of(Page, Dummy))
         deserializedPage.content.every { it instanceof Dummy }
         deserializedPage == page
+
+        when:"Serialize and deserialize empty page"
+        json = serdeMapper.writeValueAsString(Page.empty())
+
+        then:"It is done without errors"
+        def deserializedEmptyPage = serdeMapper.readValue(json, Argument.of(Page, Dummy))
+        !deserializedEmptyPage.hasTotalSize()
     }
 
     void "test serialization and deserialization of a pageable - serde"() {