Add a strict object type resolver builder (#111)

Author: Selindek

xapi-model/src/main/java/dev/learning/xapi/jackson/StrictObjectTypeResolverBuilder.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2016-2023 Berry Cloud Ltd. All rights reserved.
+ */
+
+package dev.learning.xapi.jackson;
+
+import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.databind.BeanProperty;
+import com.fasterxml.jackson.databind.DeserializationConfig;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JavaType;
+import com.fasterxml.jackson.databind.jsontype.NamedType;
+import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
+import com.fasterxml.jackson.databind.jsontype.TypeIdResolver;
+import com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer;
+import com.fasterxml.jackson.databind.jsontype.impl.StdTypeResolverBuilder;
+import com.fasterxml.jackson.databind.util.TokenBuffer;
+import dev.learning.xapi.model.ObjectType;
+import java.io.IOException;
+import java.util.Collection;
+
+/**
+ * Custom TypeResolverBuilder which accepts only valid strings as type identifiers.
+ *
+ * @author István Rátkai (Selindek)
+ */
+public class StrictObjectTypeResolverBuilder extends StdTypeResolverBuilder {
+
+  @Override
+  public TypeDeserializer buildTypeDeserializer(DeserializationConfig config, JavaType baseType,
+      Collection<NamedType> subtypes) {
+    final var subTypeValidator = verifyBaseTypeValidity(config, baseType);
+    final var idRes = idResolver(config, baseType, subTypeValidator, subtypes, false, true);
+    final var defaultImpl = defineDefaultImpl(config, baseType);
+
+    return new StrictObjectTypePropertyDeserializer(baseType, idRes, _typeProperty, _typeIdVisible,
+        defaultImpl, _includeAs);
+
+  }
+
+  /**
+   * Custom {@link AsPropertyTypeDeserializer} which accepts only valid {@link ObjectType} as
+   * property value.
+   */
+  public static class StrictObjectTypePropertyDeserializer extends AsPropertyTypeDeserializer {
+
+    private static final long serialVersionUID = 1139909729567678431L;
+
+    public StrictObjectTypePropertyDeserializer(JavaType baseType, TypeIdResolver idRes,
+        String typeProperty, boolean typeIdVisible, JavaType defaultImpl, As includeAs) {
+      super(baseType, idRes, typeProperty, typeIdVisible, defaultImpl, includeAs);
+    }
+
+    public StrictObjectTypePropertyDeserializer(AsPropertyTypeDeserializer src,
+        BeanProperty property) {
+      super(src, property);
+    }
+
+    @Override
+    public TypeDeserializer forProperty(BeanProperty prop) {
+      return (prop == _property) ? this : new StrictObjectTypePropertyDeserializer(this, prop);
+    }
+
+    @Override
+    protected Object _deserializeTypedForId(JsonParser p, DeserializationContext ctxt,
+        TokenBuffer tb, String typeId) throws IOException {
+
+      // This is the actual custom logic.
+      if (ObjectType.getByValue(typeId).isEmpty()) {
+        throw ctxt.instantiationException(null, "Invalid objectType: " + typeId);
+      }
+      // Everything else is just unavoidable duplication of the original code.
+
+      return super._deserializeTypedForId(p, ctxt, tb, typeId);
+    }
+
+  }
+
+}

xapi-model/src/main/java/dev/learning/xapi/model/Activity.java

@@ -4,6 +4,8 @@
 
 package dev.learning.xapi.model;
 
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import dev.learning.xapi.model.validation.constraints.ValidActivityDefinition;
 import jakarta.validation.Valid;
 import jakarta.validation.constraints.NotNull;
@@ -27,6 +29,7 @@
 @Builder
 @AllArgsConstructor
 @EqualsAndHashCode(exclude = "definition")
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public class Activity implements StatementObject, SubStatementObject {
 
   /**

xapi-model/src/main/java/dev/learning/xapi/model/Actor.java

@@ -10,6 +10,8 @@
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import dev.learning.xapi.model.validation.constraints.Mbox;
 import jakarta.validation.Valid;
 import java.net.URI;
@@ -39,6 +41,7 @@
     @JsonSubTypes.Type(value = Agent.class, name = "Person"),
     @JsonSubTypes.Type(value = Group.class, name = "Group")})
 @JsonInclude(Include.NON_EMPTY)
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public abstract class Actor implements StatementObject, SubStatementObject {
 
   /**

xapi-model/src/main/java/dev/learning/xapi/model/Agent.java

@@ -5,6 +5,8 @@
 package dev.learning.xapi.model;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.NoArgsConstructor;
@@ -24,6 +26,7 @@
 @EqualsAndHashCode(callSuper = true)
 @ToString(callSuper = true)
 @JsonIgnoreProperties(value = {"firstName", "lastName"})
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public class Agent extends Actor {
 
   // **Warning** do not add fields that are not required by the xAPI specification.

xapi-model/src/main/java/dev/learning/xapi/model/Attachment.java

@@ -12,10 +12,10 @@
 import java.net.URI;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.util.Locale;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
+import lombok.SneakyThrows;
 import lombok.Value;
 import lombok.With;
 
@@ -201,23 +201,19 @@ public Builder content(String content) {
 
     }
 
+    @SneakyThrows
     private static String sha256Hex(byte[] data) {
-      try {
-        final var digest = MessageDigest.getInstance("SHA-256");
-        final var hash = digest.digest(data);
-        final var hexString = new StringBuilder(2 * hash.length);
-        for (final byte element : hash) {
-          final var hex = Integer.toHexString(0xff & element);
-          if (hex.length() == 1) {
-            hexString.append('0');
-          }
-          hexString.append(hex);
+      final var digest = MessageDigest.getInstance("SHA-256");
+      final var hash = digest.digest(data);
+      final var hexString = new StringBuilder(2 * hash.length);
+      for (final byte element : hash) {
+        final var hex = Integer.toHexString(0xff & element);
+        if (hex.length() == 1) {
+          hexString.append('0');
         }
-        return hexString.toString();
-      } catch (final NoSuchAlgorithmException e) {
-        throw new IllegalArgumentException(e);
+        hexString.append(hex);
       }
-
+      return hexString.toString();
     }
   }
 

xapi-model/src/main/java/dev/learning/xapi/model/Group.java

@@ -6,6 +6,8 @@
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import dev.learning.xapi.model.validation.constraints.ValidActor;
 import jakarta.validation.Valid;
 import java.util.ArrayList;
@@ -29,6 +31,7 @@
 @AllArgsConstructor
 @EqualsAndHashCode(callSuper = true)
 @ToString(callSuper = true)
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public class Group extends Actor {
 
   /**

xapi-model/src/main/java/dev/learning/xapi/model/ObjectType.java

@@ -5,6 +5,8 @@
 package dev.learning.xapi.model;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.Arrays;
+import java.util.Optional;
 
 /**
  * This enumeration class represents all valid xAPI object types.
@@ -17,13 +19,13 @@ public enum ObjectType {
    * Activity object type.
    */
   @JsonProperty("Activity")
-  ACTIVITY,
+  ACTIVITY("Activity"),
 
   /**
    * Agent object type.
    */
   @JsonProperty("Agent")
-  AGENT,
+  AGENT("Agent"),
 
   /**
    * Person object type.
@@ -36,25 +38,35 @@ public enum ObjectType {
    *      Statements to 1.0.0</a>
    */
   @JsonProperty("Person")
-  PERSON,
+  PERSON("Person"),
 
   /**
    * Group object type.
    */
   @JsonProperty("Group")
-  GROUP,
+  GROUP("Group"),
 
   /**
    * SubStatement object type.
    */
   @JsonProperty("SubStatement")
-  SUBSTATEMENT,
+  SUBSTATEMENT("SubStatement"),
 
   /**
    * StatementRef object type.
    */
   @JsonProperty("StatementRef")
-  STATEMENTREF;
+  STATEMENTREF("StatementRef");
+
+  private String value;
+
+  ObjectType(String value) {
+    this.value = value;
+  }
+
+  public static Optional<ObjectType> getByValue(String url) {
+    return Arrays.stream(ObjectType.values()).filter(env -> env.value.equals(url)).findFirst();
+  }
 
   // **Warning** do not add fields that are not required by the xAPI specification.
 }

xapi-model/src/main/java/dev/learning/xapi/model/StatementObject.java

@@ -9,6 +9,8 @@
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 
 /**
  * This interface represents the xAPI statement object.
@@ -26,6 +28,7 @@
     @JsonSubTypes.Type(value = Group.class, name = "Group"),
     @JsonSubTypes.Type(value = SubStatement.class, name = "SubStatement"),
     @JsonSubTypes.Type(value = StatementReference.class, name = "StatementRef")})
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public interface StatementObject {
 
 }

xapi-model/src/main/java/dev/learning/xapi/model/StatementReference.java

@@ -4,6 +4,8 @@
 
 package dev.learning.xapi.model;
 
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import dev.learning.xapi.model.validation.constraints.Variant;
 import jakarta.validation.constraints.NotNull;
 import java.util.UUID;
@@ -21,6 +23,7 @@
  */
 @Value
 @Builder
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public class StatementReference implements StatementObject, SubStatementObject {
 
   /**

xapi-model/src/main/java/dev/learning/xapi/model/SubStatement.java

@@ -4,6 +4,8 @@
 
 package dev.learning.xapi.model;
 
+import com.fasterxml.jackson.databind.annotation.JsonTypeResolver;
+import dev.learning.xapi.jackson.StrictObjectTypeResolverBuilder;
 import dev.learning.xapi.model.validation.constraints.ValidActor;
 import dev.learning.xapi.model.validation.constraints.ValidStatementPlatform;
 import dev.learning.xapi.model.validation.constraints.ValidStatementRevision;
@@ -30,6 +32,7 @@
 @ValidStatementPlatform
 @ValidStatementRevision
 @EqualsAndHashCode(exclude = {"timestamp", "attachments"})
+@JsonTypeResolver(StrictObjectTypeResolverBuilder.class)
 public class SubStatement implements StatementObject, CoreStatement {
 
   /**
@@ -171,7 +174,7 @@ public Builder verb(Verb verb) {
      */
     public Builder addAttachment(Consumer<Attachment.Builder> attachment) {
 
-      final Attachment.Builder builder = Attachment.builder();
+      final var builder = Attachment.builder();
 
       attachment.accept(builder);