use custom serializers for Entity and Schema (#170)

CedarJava/src/main/java/com/cedarpolicy/CedarJson.java

@@ -16,7 +16,11 @@
 
 package com.cedarpolicy;
 
+import com.cedarpolicy.model.entity.Entity;
+import com.cedarpolicy.model.schema.Schema;
 import com.cedarpolicy.model.slice.Slice;
+import com.cedarpolicy.serializer.EntitySerializer;
+import com.cedarpolicy.serializer.SchemaSerializer;
 import com.cedarpolicy.serializer.SliceSerializer;
 import com.cedarpolicy.serializer.ValueDeserializer;
 import com.cedarpolicy.serializer.ValueSerializer;
@@ -50,6 +54,8 @@ private static ObjectMapper createObjectMapper() {
         final ObjectMapper mapper = new ObjectMapper();
 
         final SimpleModule module = new SimpleModule();
+        module.addSerializer(Entity.class, new EntitySerializer());
+        module.addSerializer(Schema.class, new SchemaSerializer());
         module.addSerializer(Slice.class, new SliceSerializer());
         module.addSerializer(Value.class, new ValueSerializer());
         module.addDeserializer(Value.class, new ValueDeserializer());

CedarJava/src/main/java/com/cedarpolicy/model/policy/Policy.java

@@ -60,6 +60,20 @@ public Policy(
         this.policyID = policyID;
     }
 
+    /**
+     * Get the policy ID.
+     */
+    public String getID() {
+        return policyID;
+    }
+
+    /**
+     * Get the policy source.
+     */
+    public String getSource() {
+        return policySrc;
+    }
+
     @Override
     public String toString() {
         return "// Policy ID: " + policyID + "\n" + policySrc;

CedarJava/src/main/java/com/cedarpolicy/model/policy/PolicySet.java

@@ -22,8 +22,9 @@
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
-
+import java.util.stream.Collectors;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -67,6 +68,24 @@ public PolicySet(Set<Policy> policies, Set<Policy> templates, List<TemplateLink>
         this.templateLinks = templateLinks;
     }
 
+    /**
+     * Get the static policies in the policy set.
+     *
+     * @return A map from policy id to `Policy` object
+     */
+    public Map<String, String> getStaticPolicies() {
+        return policies.stream().collect(Collectors.toMap(Policy::getID, Policy::getSource));
+    }
+
+    /**
+     * Get the templates in the policy set.
+     *
+     * @return A map from policy id to `Policy` object
+     */
+    public Map<String, String> getTemplates() {
+        return templates.stream().collect(Collectors.toMap(Policy::getID, Policy::getSource));
+    }
+
     /**
      * Parse multiple policies and templates from a file into a PolicySet.
      * @param filePath the path to the file containing the policies

CedarJava/src/main/java/com/cedarpolicy/model/schema/Schema.java

@@ -18,10 +18,8 @@
 
 import com.cedarpolicy.loader.LibraryLoader;
 import com.cedarpolicy.model.exception.InternalException;
-import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 
 import java.util.Optional;
@@ -36,13 +34,12 @@ public final class Schema {
     }
 
     /** Is this schema in the JSON or human format */
-    @JsonIgnore
     public final JsonOrHuman type;
+
     /** This will be present if and only if `type` is `Json`. */
-    @JsonProperty("json")
-    private final Optional<JsonNode> schemaJson;
+    public final Optional<JsonNode> schemaJson;
+
     /** This will be present if and only if `type` is `Human`. */
-    @JsonProperty("human")
     public final Optional<String> schemaText;
 
     /**

CedarJava/src/main/java/com/cedarpolicy/model/slice/BasicSlice.java

@@ -20,7 +20,6 @@
 import com.cedarpolicy.model.policy.Policy;
 import com.cedarpolicy.model.policy.TemplateLink;
 import com.cedarpolicy.value.Value;
-import com.fasterxml.jackson.annotation.JsonProperty;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import java.util.*;
@@ -37,10 +36,8 @@ public class BasicSlice implements Slice {
 
     private final Set<Entity> entities;
 
-    @JsonProperty("templatePolicies")
     private final Map<String, String> templatePolicies;
 
-    @JsonProperty("templateInstantiations")
     private final List<TemplateLink> templateLinks;
 
     /**

CedarJava/src/main/java/com/cedarpolicy/serializer/EntitySerializer.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2022-2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.cedarpolicy.serializer;
+
+import com.cedarpolicy.model.entity.Entity;
+import com.cedarpolicy.value.EntityUID;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import java.io.IOException;
+import java.util.stream.Collectors;
+
+/** Serialize an entity. */
+public class EntitySerializer extends JsonSerializer<Entity> {
+
+    /** Serialize an entity. */
+    @Override
+    public void serialize(
+            Entity entity, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
+            throws IOException {
+        jsonGenerator.writeStartObject();
+        jsonGenerator.writeObjectField("uid", entity.getEUID().asJson());
+        jsonGenerator.writeObjectField("attrs", entity.attrs);
+        jsonGenerator.writeObjectField("parents",
+                entity.getParents().stream().map(EntityUID::asJson).collect(Collectors.toSet()));
+        jsonGenerator.writeEndObject();
+    }
+}

CedarJava/src/main/java/com/cedarpolicy/serializer/JsonEUID.java

@@ -20,14 +20,10 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
-import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.cedarpolicy.value.EntityUID;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 /** Represent JSON format of Entity Unique Identifier. */
-@JsonDeserialize
-@JsonSerialize
 public class JsonEUID {
     /** euid (__entity is used as escape sequence in JSON). */
     @JsonProperty("type")

CedarJava/src/main/java/com/cedarpolicy/serializer/SchemaSerializer.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2022-2023 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.cedarpolicy.serializer;
+
+import com.cedarpolicy.model.schema.Schema;
+import com.cedarpolicy.model.schema.Schema.JsonOrHuman;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import java.io.IOException;
+
+/** Serialize a schema. */
+public class SchemaSerializer extends JsonSerializer<Schema> {
+
+    /** Serialize a schema. */
+    @Override
+    public void serialize(
+            Schema schema, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
+            throws IOException {
+        jsonGenerator.writeStartObject();
+        if (schema.type == JsonOrHuman.Json) {
+            jsonGenerator.writeObjectField("json", schema.schemaJson.get());
+        } else {
+            jsonGenerator.writeStringField("human", schema.schemaText.get());
+        }
+        jsonGenerator.writeEndObject();
+    }
+}

CedarJava/src/main/java/com/cedarpolicy/serializer/SliceSerializer.java

@@ -16,18 +16,11 @@
 
 package com.cedarpolicy.serializer;
 
-import com.cedarpolicy.model.entity.Entity;
 import com.cedarpolicy.model.slice.Slice;
-import com.cedarpolicy.value.Value;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.JsonSerializer;
 import com.fasterxml.jackson.databind.SerializerProvider;
-import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.IOException;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.stream.Collectors;
 
 /** Serialize a slice. Only used internally by CedarJson */
 public class SliceSerializer extends JsonSerializer<Slice> {
@@ -39,36 +32,10 @@ public void serialize(
             throws IOException {
         jsonGenerator.writeStartObject();
         jsonGenerator.writeObjectField("policies", slice.getPolicies());
-        jsonGenerator.writeObjectField(
-                "entities", convertEntitiesToJsonEntities(slice.getEntities()));
+        jsonGenerator.writeObjectField("entities", slice.getEntities());
         jsonGenerator.writeObjectField("templates", slice.getTemplates());
         jsonGenerator.writeObjectField(
                 "templateInstantiations", slice.getTemplateLinks());
         jsonGenerator.writeEndObject();
     }
-
-    private static class JsonEntity {
-        /** Entity uid for the entity. */
-        @SuppressFBWarnings public final JsonEUID uid;
-
-        /** Entity attributes, where the value string is a Cedar literal value. */
-        @SuppressFBWarnings public final Map<String, Value> attrs;
-
-        /** Set of direct parent entities of this entity. */
-        public final Set<JsonEUID> parents;
-
-        JsonEntity(Entity e) {
-            this.uid = e.getEUID().asJson();
-            this.attrs = e.attrs;
-            this.parents = e.getParents().stream().map(euid -> euid.asJson()).collect(Collectors.toSet());
-        }
-    }
-
-    Set<JsonEntity> convertEntitiesToJsonEntities(Set<Entity> entities) {
-        Set<JsonEntity> ret = new HashSet<JsonEntity>();
-        for (Entity entity : entities) {
-            ret.add(new JsonEntity(entity));
-        }
-        return ret;
-    }
 }

CedarJava/src/test/java/com/cedarpolicy/JSONTests.java

@@ -166,7 +166,7 @@ public void testEntityUID() {
         ObjectNode inner = JsonNodeFactory.instance.objectNode();
         inner.put("id", "jakob");
         inner.put("type", "silver");
-        n.put(ENTITY_ESCAPE_SEQ, inner);
+        n.replace(ENTITY_ESCAPE_SEQ, inner);
         assertJSONEqual(n, uid);
 
         String invalidNamespace = "Us,er::\"alice\"";
@@ -181,7 +181,7 @@ public void testEntityUID() {
         inner = JsonNodeFactory.instance.objectNode();
         inner.put("id", "ali\"ce");
         inner.put("type", "User");
-        n.put(ENTITY_ESCAPE_SEQ, inner);
+        n.replace(ENTITY_ESCAPE_SEQ, inner);
         assertJSONEqual(n, uid);
 
         String weirdType = "a";
@@ -191,7 +191,7 @@ public void testEntityUID() {
         inner = JsonNodeFactory.instance.objectNode();
         inner.put("id", weirdId);
         inner.put("type", weirdType);
-        n.put(ENTITY_ESCAPE_SEQ, inner);
+        n.replace(ENTITY_ESCAPE_SEQ, inner);
         assertJSONEqual(n, uid);
     }
 
@@ -200,7 +200,7 @@ private ObjectNode buildEuidObject(String type, String id) {
         var inner = JsonNodeFactory.instance.objectNode();
         inner.put("id", id);
         inner.put("type", type);
-        n.put(ENTITY_ESCAPE_SEQ, inner);
+        n.replace(ENTITY_ESCAPE_SEQ, inner);
         return n;
     }
 
@@ -213,7 +213,7 @@ public void testLongEntityUID() {
         ObjectNode inner = JsonNodeFactory.instance.objectNode();
         inner.put("id", "donut");
         inner.put("type", "long::john::silver");
-        n.put(ENTITY_ESCAPE_SEQ, inner);
+        n.replace(ENTITY_ESCAPE_SEQ, inner);
         assertJSONEqual(n, uid);
     }
 

CedarJava/src/test/java/com/cedarpolicy/SharedIntegrationTests.java

@@ -38,7 +38,6 @@
 import com.cedarpolicy.serializer.JsonEUID;
 import com.cedarpolicy.value.Value;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
 import java.io.FileInputStream;
@@ -91,7 +90,6 @@ private Path resolveIntegrationTestPath(String path) {
      * populated by Jackson when the test files are deserialized.
      */
     @SuppressWarnings("visibilitymodifier")
-    @JsonDeserialize
     private static class JsonTest {
         /**
          * File name of the file containing policies. Path is relative to the integration tests
@@ -123,7 +121,6 @@ private static class JsonTest {
 
     /** Directly corresponds to the structure of a request in the JSON formatted tests files. */
     @SuppressWarnings("visibilitymodifier")
-    @JsonDeserialize
     private static class JsonRequest {
         /** Textual description of the request. */
         public String description;
@@ -159,7 +156,6 @@ private static class JsonRequest {
      * String, rather than String to Values.
      */
     @SuppressWarnings("visibilitymodifier")
-    @JsonDeserialize
     private static class JsonEntity {
         /** Entity uid for the entity. */
         @SuppressFBWarnings(