Fix serialization of beans that are annotated with @JsonTypeInfo() (#26)

dhenneke · Phil404 · langecode · commit 204fee3e4bbf · 2020-01-15T19:30:17.000+01:00
* Add test cases for polymorphic classes

We have currently a problem with polymorphic classes.
They could not created by HALMapper in the correct HAL structure.
Except the polymorphic class is in a other class embedded.

* Add test cases for polymorphic classes without List and other Annotation (as.property)

* Fix serialization of beans that are annotated with @JsonTypeInfo()

Co-authored-by: Philipp Westphalen &lt;philipp.westphalen@sda.se&gt;
diff --git a/src/main/java/io/openapitools/jackson/dataformat/hal/ser/HALBeanSerializer.java b/src/main/java/io/openapitools/jackson/dataformat/hal/ser/HALBeanSerializer.java
@@ -1,11 +1,15 @@
 package io.openapitools.jackson.dataformat.hal.ser;
 
 import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonToken;
+import com.fasterxml.jackson.core.type.WritableTypeId;
 import com.fasterxml.jackson.databind.BeanDescription;
 import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
 import com.fasterxml.jackson.databind.ser.BeanPropertyWriter;
 import com.fasterxml.jackson.databind.ser.impl.ObjectIdWriter;
 import com.fasterxml.jackson.databind.ser.std.BeanSerializerBase;
+import com.fasterxml.jackson.databind.util.NameTransformer;
 import io.openapitools.jackson.dataformat.hal.HALLink;
 import io.openapitools.jackson.dataformat.hal.annotation.Curie;
 import io.openapitools.jackson.dataformat.hal.annotation.Curies;
@@ -63,7 +67,23 @@ protected BeanSerializerBase withIgnorals(Set<String> set) {
     @Override
     public void serialize(Object bean, JsonGenerator jgen, SerializerProvider provider) throws IOException {
         FilteredProperties filtered = new FilteredProperties(bean, provider, beanDescription);
+
+        // this serializer acts autonomous and creates the complete object
+        jgen.writeStartObject();
+        filtered.serialize(bean, jgen, provider);
+        jgen.writeEndObject();
+    }
+
+    @Override
+    public void serializeWithType(Object bean, JsonGenerator jgen, SerializerProvider provider,
+        TypeSerializer typeSer) throws IOException {
+        FilteredProperties filtered = new FilteredProperties(bean, provider, beanDescription);
+
+        // this serializer lets the TypeSerializer create the outer frame and inserts the rest of the object
+        WritableTypeId typeIdDef = _typeIdDef(typeSer, bean, JsonToken.START_OBJECT);
+        typeSer.writeTypePrefix(jgen, typeIdDef);
         filtered.serialize(bean, jgen, provider);
+        typeSer.writeTypeSuffix(jgen, typeIdDef);
     }
 
     /**
@@ -160,8 +180,6 @@ private void populateCurieMap(BeanDescription beanDescription) {
         }
 
         public void serialize(Object bean, JsonGenerator jgen, SerializerProvider provider) throws IOException {
-            jgen.writeStartObject();
-
             if (!links.isEmpty()) {
                 jgen.writeFieldName("_links");
                 jgen.writeStartObject();
@@ -177,8 +195,11 @@ public void serialize(Object bean, JsonGenerator jgen, SerializerProvider provid
                 jgen.writeStartObject();
                 for (String rel : embedded.keySet()) {
                     try {
-                        jgen.writeFieldName(rel);
-                        jgen.writeObject(embedded.get(rel).get(bean));
+                        // use the relation as new name for the original property
+                        BeanPropertyWriter prop = renameBeanProperty(embedded.get(rel), rel);
+
+                        // serialize the field as normal field
+                        prop.serializeAsField(bean, jgen, provider);
                     } catch (Exception e) {
                         wrapAndThrow(provider, e, bean, rel);
                     }
@@ -193,8 +214,6 @@ public void serialize(Object bean, JsonGenerator jgen, SerializerProvider provid
                     wrapAndThrow(provider, e, bean, prop.getName());
                 }
             }
-
-            jgen.writeEndObject();
         }
 
         private void addEmbeddedProperty(String rel, BeanPropertyWriter property) {
@@ -219,8 +238,22 @@ private String applyCurieToRel(String rel, String curie) {
             return (null == curie) ? rel : curie + ":" + rel;
         }
 
+        private BeanPropertyWriter renameBeanProperty(BeanPropertyWriter prop, String newName) {
+            return prop.rename(new NameTransformer() {
+                @Override
+                public String transform(String name) {
+                    return newName;
+                }
+
+                @Override
+                public String reverse(String transformed) {
+                    return null;
+                }
+            });
+        }
     }
 
+
     /**
      * Representing either a single link (one-to-one relation) or a collection of links.
      */
diff --git a/src/test/java/io/openapitoools/jackson/dataformat/hal/ser/HALBeanSerializerPolymorphicWithExistingFieldIT.java b/src/test/java/io/openapitoools/jackson/dataformat/hal/ser/HALBeanSerializerPolymorphicWithExistingFieldIT.java
@@ -0,0 +1,201 @@
+package io.openapitoools.jackson.dataformat.hal.ser;
+
+import static org.junit.Assert.assertEquals;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
+import com.fasterxml.jackson.annotation.JsonTypeInfo.Id;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.openapitools.jackson.dataformat.hal.HALLink;
+import io.openapitools.jackson.dataformat.hal.HALMapper;
+import io.openapitools.jackson.dataformat.hal.annotation.EmbeddedResource;
+import io.openapitools.jackson.dataformat.hal.annotation.Link;
+import io.openapitools.jackson.dataformat.hal.annotation.Resource;
+import java.net.URI;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import org.junit.Test;
+
+public class HALBeanSerializerPolymorphicWithExistingFieldIT {
+
+  ObjectMapper om = new HALMapper();
+
+  @Test
+  public void testSerializationForResourceWithEmbeddableList() throws Exception {
+    @Resource
+    class TopResource {
+
+      public String id = "1";
+
+      @Link public HALLink self = new HALLink.Builder(URI.create("/top/1")).build();
+
+      @Link("child")
+      public List<HALLink> childResourcesLink =
+          Arrays.asList(
+              new HALLink.Builder(URI.create("/top/1/child/1")).build(),
+              new HALLink.Builder(URI.create("/top/1/child/2")).build());
+
+      @EmbeddedResource("child")
+      public Collection<ChildResource> children =
+          Arrays.asList(new ChildResource("1"), new OtherChildResource("2", "Max"));
+    }
+
+    TopResource resource = new TopResource();
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"child\":[{\"href\":\"/top/1/child/1\"},{\"href\":\"/top/1/child/2\"}],"
+            + "\"self\":{\"href\":\"/top/1\"}"
+            + "},"
+            + "\"_embedded\":{"
+            + "\"child\":["
+            + "{\"_links\":{\"self\":{\"href\":\"/top/1/child/1\"}},\"type\":\"ChildResource\",\"id\":\"1\"},"
+            + "{\"_links\":{\"self\":{\"href\":\"/top/1/child/2\"}},\"type\":\"OtherChildResource\",\"id\":\"2\",\"name\":\"Max\"}]"
+            + "},"
+            + "\"id\":\"1\"}",
+        json);
+  }
+
+  @Test
+  public void testSerializationForResourceWithList() throws Exception {
+    @Resource
+    class TopResourceWithoutEmbedded {
+      public String id = "1";
+
+      @Link public HALLink self = new HALLink.Builder(URI.create("/top/1")).build();
+
+      public Collection<ChildResource> children =
+          Arrays.asList(new ChildResource("1"), new OtherChildResource("2", "Max"));
+    }
+
+    TopResourceWithoutEmbedded resource = new TopResourceWithoutEmbedded();
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"self\":{\"href\":\"/top/1\"}"
+            + "},"
+            + "\"id\":\"1\","
+            + "\"children\":["
+            + "{\"_links\":{\"self\":{\"href\":\"/top/1/child/1\"}},\"type\":\"ChildResource\",\"id\":\"1\"},"
+            + "{\"_links\":{\"self\":{\"href\":\"/top/1/child/2\"}},\"type\":\"OtherChildResource\",\"id\":\"2\",\"name\":\"Max\"}]"
+            + "}",
+        json);
+  }
+
+  @Test
+  public void testSerializationForResourceEmbedded() throws Exception {
+    @Resource
+    class SimpleTopResourceEmbedded {
+      public String id = "1";
+
+      @Link public HALLink self = new HALLink.Builder(URI.create("/top/1")).build();
+
+      @EmbeddedResource public ChildResource child = new ChildResource("1");
+    }
+
+    SimpleTopResourceEmbedded resource = new SimpleTopResourceEmbedded();
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"self\":{\"href\":\"/top/1\"}"
+            + "},"
+            + "\"_embedded\":{"
+            + "\"child\":{\"_links\":{\"self\":{\"href\":\"/top/1/child/1\"}},\"type\":\"ChildResource\",\"id\":\"1\"}"
+            + "},"
+            + "\"id\":\"1\"}",
+        json);
+  }
+
+  @Test
+  public void testSerializationForResource() throws Exception {
+    @Resource
+    class SimpleTopResource {
+      public String id = "1";
+
+      @Link public HALLink self = new HALLink.Builder(URI.create("/top/1")).build();
+
+      public ChildResource child = new ChildResource("1");
+    }
+
+    SimpleTopResource resource = new SimpleTopResource();
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"self\":{\"href\":\"/top/1\"}"
+            + "},"
+            + "\"id\":\"1\","
+            + "\"child\":{"
+            + "\"_links\":{\"self\":{\"href\":\"/top/1/child/1\"}},\"type\":\"ChildResource\",\"id\":\"1\""
+            + "}}",
+        json);
+  }
+
+  @Test
+  public void testSerializationForAnnotatedPolymorphicObject() throws Exception {
+    ChildResource resource = new ChildResource("1");
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"self\":{\"href\":\"/top/1/child/1\"}"
+            + "},"
+            + "\"type\":\"ChildResource\","
+            + "\"id\":\"1\"}",
+        json);
+  }
+
+  @Test
+  public void testSerializationForNotAnnotatedPolymorphicObject() throws Exception {
+    ChildResource resource = new OtherChildResource("1", "Max");
+    String json = om.writeValueAsString(resource);
+    assertEquals(
+        "{"
+            + "\"_links\":{"
+            + "\"self\":{\"href\":\"/top/1/child/1\"}"
+            + "},"
+            + "\"type\":\"OtherChildResource\","
+            + "\"id\":\"1\","
+            + "\"name\":\"Max\"}",
+        json);
+  }
+
+  @JsonTypeInfo(
+      use = Id.NAME,
+      include = As.EXISTING_PROPERTY,
+      property = "type",
+      defaultImpl = ChildResource.class)
+  @JsonSubTypes({@JsonSubTypes.Type(value = OtherChildResource.class, name = "OtherChildResource")})
+  @Resource
+  public static class ChildResource {
+
+    public String type = "ChildResource";
+
+    public String id;
+
+    @Link public HALLink self;
+
+    public ChildResource(String id) {
+      this.id = id;
+      self = new HALLink.Builder(URI.create("/top/1/child/" + id)).build();
+    }
+  }
+
+  @Resource
+  public static class OtherChildResource extends ChildResource {
+
+    public String type = "OtherChildResource";
+
+    public String name;
+
+    public OtherChildResource(String id, String name) {
+      super(id);
+      this.name = name;
+    }
+  }
+}
diff --git a/src/test/java/io/openapitoools/jackson/dataformat/hal/ser/HALBeanSerializerPolymorphicWithPropertyIT.java b/src/test/java/io/openapitoools/jackson/dataformat/hal/ser/HALBeanSerializerPolymorphicWithPropertyIT.java
