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JooHyukKimJooHyukKim
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Allow @JsonMerge with Custom List (#4784)
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-10
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3 files changed

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‎release-notes/VERSION-2.x

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Original file line numberDiff line numberDiff line change
@@ -16,6 +16,9 @@ Project: jackson-databind
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#4790: Fix `@JsonAnySetter` issue with "setter" method (related to #4639)
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(reported by @bsa01)
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(fix by Joo-Hyuk K)
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#4783 Possibly wrong behavior of @JsonMerge
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(reported by @nlisker)
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(fix by Joo-Hyuk K)
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2023
2.18.1 (28-Oct-2024)
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‎src/main/java/com/fasterxml/jackson/databind/deser/BasicDeserializerFactory.java

+4-10
Original file line numberDiff line numberDiff line change
@@ -824,13 +824,7 @@ public JsonDeserializer<?> createCollectionDeserializer(DeserializationContext c
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if (deser == null) {
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if (type.isInterface() || type.isAbstract()) {
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CollectionType implType = _mapAbstractCollectionType(type, config);
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if (implType == null) {
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// [databind#292]: Actually, may be fine, but only if polymorphich deser enabled
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if (type.getTypeHandler() == null) {
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throw new IllegalArgumentException("Cannot find a deserializer for non-concrete Collection type "+type);
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}
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deser = AbstractDeserializer.constructForNonPOJO(beanDesc);
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} else {
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if (implType != null) {
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type = implType;
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// But if so, also need to re-check creators...
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beanDesc = config.introspectForCreation(type);
@@ -972,9 +966,9 @@ public JsonDeserializer<?> createMapDeserializer(DeserializationContext ctxt,
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*/
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if (deser == null) {
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if (type.isInterface() || type.isAbstract()) {
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MapType fallback = _mapAbstractMapType(type, config);
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if (fallback != null) {
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type = (MapType) fallback;
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MapType implType = _mapAbstractMapType(type, config);
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if (implType != null) {
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type = (MapType) implType;
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mapClass = type.getRawClass();
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// But if so, also need to re-check creators...
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beanDesc = config.introspectForCreation(type);

‎src/test/java/com/fasterxml/jackson/databind/deser/merge/CustomCollectionMerge4783Test.java

+148
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,148 @@
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package com.fasterxml.jackson.databind.deser.merge;
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import java.util.ArrayList;
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import java.util.List;
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import org.junit.jupiter.api.Test;
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import com.fasterxml.jackson.annotation.JsonMerge;
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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 com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
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import com.fasterxml.jackson.databind.testutil.DatabindTestUtil;
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import static org.junit.jupiter.api.Assertions.assertEquals;
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import static org.junit.jupiter.api.Assertions.assertTrue;
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import static org.junit.jupiter.api.Assertions.fail;
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// [databind#4783] Test to verify that JsonMerge also works for custom list
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@SuppressWarnings("serial")
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public class CustomCollectionMerge4783Test
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extends DatabindTestUtil
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{
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static class MyArrayListJDK<T> extends ArrayList<T> { }
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static class MergeListJDK {
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@JsonMerge
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@JsonProperty
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public List<String> values = new MyArrayListJDK<>();
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{ values.add("a");}
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}
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interface MyListCustom<T> extends List<T> { }
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static class MyArrayListCustom<T> extends ArrayList<T> implements MyListCustom<T> { }
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static abstract class MyAbstractStringList extends ArrayList<String> {
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MyAbstractStringList() { super(); }
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MyAbstractStringList(int i) { super(); }
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}
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static class MergeCustomStringList {
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@JsonMerge
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@JsonProperty
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public MyListCustom<String> values = new MyArrayListCustom<>();
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{ values.add("a"); }
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}
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static class MergeMyCustomLongList {
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@JsonMerge
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@JsonProperty
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public MyListCustom<Long> values = new MyArrayListCustom<>();
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{ values.add(1L); }
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}
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static class MergeMyCustomPojoList {
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@JsonMerge
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@JsonProperty
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public MyListCustom<CustomPojo> values = new MyArrayListCustom<>();
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{
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values.add(CustomPojo.create("a", 1));
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values.add(CustomPojo.create("b", 2));
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}
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}
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// And then non-merging case too
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static class NonMergeCustomStringList {
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public MyListCustom<String> values;
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}
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public static class CustomPojo {
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public String name;
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public int age;
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public static CustomPojo create(String name, int age) {
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CustomPojo pojo = new CustomPojo();
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pojo.name = name;
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pojo.age = age;
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return pojo;
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}
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}
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private final ObjectMapper MAPPER = newJsonMapper();
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@Test
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void testJDKMapperReading() throws Exception {
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MergeListJDK result = MAPPER.readValue("{\"values\":[\"x\"]}", MergeListJDK.class);
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assertEquals(2, result.values.size());
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assertTrue(result.values.contains("x"));
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assertTrue(result.values.contains("a"));
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}
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@Test
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void testCustomMapperReading() throws Exception {
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MergeCustomStringList result = MAPPER.readValue("{\"values\":[\"x\"]}",
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MergeCustomStringList.class);
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assertEquals(2, result.values.size());
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assertTrue(result.values.contains("x"));
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assertTrue(result.values.contains("a"));
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}
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@Test
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void testCustomMapperReadingLongArrayList() throws Exception {
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MergeMyCustomLongList result = MAPPER.readValue("{\"values\":[7]}",
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MergeMyCustomLongList.class);
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assertEquals(2, result.values.size());
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assertTrue(result.values.contains(1L));
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assertTrue(result.values.contains(7L));
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}
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@Test
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void testCustomMapperReadingPojoArrayList() throws Exception {
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MergeMyCustomPojoList result = MAPPER.readValue("{\"values\":[{\"name\":\"c\",\"age\":3}]}",
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MergeMyCustomPojoList.class);
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assertEquals(3, result.values.size());
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}
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// // // And then failure cases
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// Fail can't construct Collection interface unless there's maaping
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@Test
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void failNonMergeInterfaceList() throws Exception {
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try {
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MAPPER.readValue("{\"values\":[\"x\"]}", NonMergeCustomStringList.class);
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fail("Should not pass");
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} catch (InvalidDefinitionException e) {
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verifyException(e, String.format(
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"Cannot construct instance of `%s` (no Creators",
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MyListCustom.class.getName()));
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}
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}
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// Fail can't construct abstract types
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@Test
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void failNonMergeAbstractList() throws Exception {
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try {
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MAPPER.readValue("[]", MyAbstractStringList.class);
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fail("Should not pass");
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} catch (InvalidDefinitionException e) {
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verifyException(e, String.format(
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"Cannot construct instance of `%s` (no Creators",
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MyAbstractStringList.class.getName()));
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}
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}
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}

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