com.fasterxml.jackson.databind.JsonDeserializer#deserialize ( )源码实例Demo

@Override
public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
    List<Object> list = new ArrayList<>();
    int ptr = 0;

    for (JsonToken jsonToken = p.nextToken(); jsonToken != END_ARRAY; jsonToken = p.nextToken()) {
        if (ptr >= deserializersCount()) {
            throw mappingException(ctxt, javaType.getRawClass(), jsonToken);
        }
        JsonDeserializer<?> deserializer = deserializer(ptr++);
        Object value = (jsonToken != VALUE_NULL) ? deserializer.deserialize(p, ctxt) : deserializer.getNullValue(ctxt);
        list.add(value);
    }
    if (list.size() == deserializersCount()) {
        return create(list, ctxt);
    } else {
        throw mappingException(ctxt, javaType.getRawClass(), null);
    }
}
 

/**
 * Helper method called when {@link JsonParser} indicates that it can use
 * so-called native type ids, and such type id has been found.
 * 
 * @since 2.4
 */
protected Object _deserializeWithNativeTypeId(JsonParser jp, DeserializationContext ctxt, Object typeId)
    throws IOException
{
    JsonDeserializer<Object> deser;
    if (typeId == null) {
        /* 04-May-2014, tatu: Should error be obligatory, or should there be another method
         *   for "try to deserialize with native tpye id"?
         */
        deser = _findDefaultImplDeserializer(ctxt);
        if (deser == null) {
            return ctxt.reportInputMismatch(baseType(),
                    "No (native) type id found when one was expected for polymorphic type handling");
        }
    } else {
        String typeIdStr = (typeId instanceof String) ? (String) typeId : String.valueOf(typeId);
        deser = _findDeserializer(ctxt, typeIdStr);
    }
    return deser.deserialize(jp, ctxt);
}
 

@Override
public PersistentMap<?, ?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
  JsonDeserializer deser = ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructRawMapType(Map.class));

  Object o = deser.deserialize(p, ctxt);
  if(HashMap.class.isAssignableFrom(mapType))
    return HashMap.fromMap((Map)o);
  if(TreeMap.class.isAssignableFrom(mapType))
    return TreeMap.fromMap((Comparator)Comparator.naturalOrder(),(Map)o);

 /** if(TrieMap.class.isAssignableFrom(mapType))
    return TrieMap.fromMap((Map)o);
  if(LinkedMap.class.isAssignableFrom(mapType))
    return LinkedMap.fromMap((Map)o);
  **/
  Optional<Method> m = streamMethod.computeIfAbsent(mapType, c-> Stream.of(c.getMethods())
    .filter(method -> "fromMap".equals(method.getName()))
    .filter(method -> method.getParameterCount()==1)
    .filter(method -> method.getParameterTypes()[0].isAssignableFrom(Map.class)).findFirst()
    .map(m2->{ m2.setAccessible(true); return m2;}));
  PersistentMap<?,?> x = m.map(mt -> (PersistentMap)new  Invoker().executeMethod(o, mt, mapType)).orElse(null);

  return x;

}
 

@Override
protected T _deserializeContents(JsonParser p, DeserializationContext ctxt) throws IOException,
        JsonProcessingException {
    JsonDeserializer<?> valueDes = _valueDeserializer;
    JsonToken t;
    final TypeDeserializer typeDeser = _valueTypeDeserializer;
    T set = createMultiset();

    while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
        Object value;

        if (t == JsonToken.VALUE_NULL) {
            if (_skipNullValues) {
                continue;
            }
            value = _nullProvider.getNullValue(ctxt);
        } else if (typeDeser == null) {
            value = valueDes.deserialize(p, ctxt);
        } else {
            value = valueDes.deserializeWithType(p, ctxt, typeDeser);
        }
        set.add(value);
    }
    return set;
}
 

@Override
public LazyEither5<?,?,?,?,?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
  JsonDeserializer ser = ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructSimpleType(LazyEitherBean.class, new JavaType[0]));
  LazyEitherBean x = (LazyEitherBean)ser.deserialize(p, ctxt);
  if(x.left1!=null){
    return LazyEither5.left1(x.left1);
  }
  if(x.left2!=null){
    return LazyEither5.left2(x.left2);
  }
  if(x.left3!=null){
    return LazyEither5.left3(x.left2);
  }
  if(x.left4!=null){
    return LazyEither5.left4(x.left2);
  }
  return LazyEither5.right(x.right);
}
 

private Object readEncoded(JsonParser p, DeserializationContext ctxt) throws IOException {
    if (!p.isExpectedStartArrayToken()) {
        throw new JsonParseException(p, "Expected array for encoded object got " + p.currentToken());
    }

    Object value = null;
    JsonToken next = p.nextToken();
    if (next != JsonToken.VALUE_STRING) {
        throw new JsonParseException(p, "Encoded Class value not present " + next);
    }
    String typeName = p.getText();
    p.nextToken(); // fwd to next
    ClassLoader loader = Thread.currentThread().getContextClassLoader();
    if (loader == null) {
        loader = getClass().getClassLoader();
    }
    try {
        Class<?> type = loader.loadClass(typeName);
        if (Collection.class.isAssignableFrom(type)) {
            value = readCollection(type, p, ctxt);
        } else if (Map.class.isAssignableFrom(type)) {
            value = readMap(type, p, ctxt);
        } else {
            JsonDeserializer<Object> deser = ctxt.findRootValueDeserializer(ctxt.constructType(type));
            value = deser.deserialize(p, ctxt);
        }
    } catch (ClassNotFoundException e) {
        throw new JsonParseException(p, "Type name encoded " + typeName + " could not be loaded", e);
    }
    if (p.nextToken() != JsonToken.END_ARRAY) {
        throw new JsonParseException(p, "Encoded expected end of ARRAY marker " + p.currentToken());
    }
    return value;
}
 

@Override
protected DeviceRenderTypeMap readValue( JsonParser jsonParser )
{
    try
    {
        JsonDeserializer<DeviceRenderTypeMap> jsonDeserializer = deserializer.newInstance();
        return jsonDeserializer.deserialize( jsonParser, MAPPER.getDeserializationContext() );
    }
    catch ( IOException | IllegalAccessException | InstantiationException e )
    {
        throw new RuntimeException( e );
    }
}
 

@Override
public LazyEither3<?,?,?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
  JsonDeserializer ser = ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructSimpleType(LazyEitherBean.class, new JavaType[0]));
  LazyEitherBean x = (LazyEitherBean)ser.deserialize(p, ctxt);
  if(x.left1!=null){
    return LazyEither3.left1(x.left1);
  }
  if(x.left2!=null){
    return LazyEither3.left2(x.left2);
  }
  return LazyEither3.right(x.right);
}
 

/**
 * Helper method called when current token is no START_ARRAY. Will either
 * throw an exception, or try to handle value as if member of implicit
 * array, depending on configuration.
 */
@SuppressWarnings("unchecked")
protected final Collection<Object> handleNonArray(JsonParser p, DeserializationContext ctxt,
    Collection<Object> result)
    throws IOException {
  // Implicit arrays from single values?
  boolean canWrap = (_unwrapSingle == Boolean.TRUE) ||
      ((_unwrapSingle == null) &&
          ctxt.isEnabled(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY));
  if (!canWrap) {
    return (Collection<Object>) ctxt.handleUnexpectedToken(_containerType.getRawClass(), p);
  }
  JsonDeserializer<Object> valueDes = _valueDeserializer;
  final TypeDeserializer typeDeser = _valueTypeDeserializer;
  JsonToken t = p.getCurrentToken();

  Object value;

  try {
    if (t == JsonToken.VALUE_NULL) {
      // 03-Feb-2017, tatu: Hmmh. I wonder... let's try skipping here, too
      if (_skipNullValues) {
        return result;
      }
      value = _nullProvider.getNullValue(ctxt);
    } else if (typeDeser == null) {
      value = valueDes.deserialize(p, ctxt);
    } else {
      value = valueDes.deserializeWithType(p, ctxt, typeDeser);
    }
  } catch (Exception e) {
    // note: pass Object.class, not Object[].class, as we need element type for error info
    throw JsonMappingException.wrapWithPath(e, Object.class, result.size());
  }
  result.add(value);
  return result;
}
 

@Override
public LazyEither<?,?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
  JsonDeserializer ser = ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructSimpleType(LazyEitherBean.class, new JavaType[0]));
  LazyEitherBean x = (LazyEitherBean)ser.deserialize(p, ctxt);
  if(x.left!=null){
    return LazyEither.left(x.left);
  }
  return LazyEither.right(x.right);
}
 

@Override
public HiveProxyingSubScan deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
  final JsonNode node = jsonParser.getCodec().readTree(jsonParser);

  final String pluginName = node.get("pluginName").asText();
  final CatalogService catalogService = (CatalogService) deserializationContext
    .findInjectableValue(CatalogService.class.getName(), null, null);

  final StoragePluginCreator.PF4JStoragePlugin plugin = catalogService.getSource(pluginName);
  final Class<? extends HiveProxiedSubScan> scanClazz = plugin.getSubScanClass();

  final JavaType scanType = deserializationContext.getTypeFactory().constructType(scanClazz);
  final BasicBeanDescription description = deserializationContext.getConfig().introspect(scanType);
  final JsonDeserializer<Object> subScanDeserializer = deserializationContext.getFactory().createBeanDeserializer(
    deserializationContext, scanType, description);

  if (subScanDeserializer instanceof ResolvableDeserializer) {
    ((ResolvableDeserializer) subScanDeserializer).resolve(deserializationContext);
  }

  final JsonParser movedParser = jsonParser.getCodec().treeAsTokens(node.get("wrappedHiveScan"));
  deserializationContext.getConfig().initialize(movedParser);

  if (movedParser.getCurrentToken() == null) {
    movedParser.nextToken();
  }

  final HiveProxiedSubScan scan = (HiveProxiedSubScan) subScanDeserializer.deserialize(movedParser, deserializationContext);
  return new HiveProxyingSubScan(pluginName, scan);
}
 

@Override
public Object deserialize(JsonParser p, DeserializationContext ctx) throws IOException {
    if(jobsManager == null) {
        throw new IllegalStateException("This deserializer need a jobsManager instance, see 'JobParametersDeserializer.setJobsManager'");
    }
    final JsonStreamContext jsc = p.getParsingContext();
    String paramName = null;
    JsonStreamContext parent = jsc;
    while(parent != null) {
        paramName = parent.getCurrentName();
        if(paramName != null) {
            break;
        }
        parent = parent.getParent();
    }
    if(parent == null) {
        throw new NullPointerException("Something wrong: we can not find our parent object, " +
          "may be you use this deserializer on custom object?");
    }
    JobParameters.Builder r = (JobParameters.Builder) parent.getParent().getCurrentValue();
    String jobType = r.getType();
    JobDescription desc = jobsManager.getDescription(jobType);
    JobParameterDescription param = desc.getParameters().get(paramName);
    TypeFactory typeFactory = ctx.getTypeFactory();
    JavaType type;
    if(param == null) {
        type = typeFactory.constructType(Object.class);
    } else {
        type = typeFactory.constructType(param.getType());
    }
    JsonDeserializer<Object> deser = ctx.findNonContextualValueDeserializer(type);
    try {
        return deser.deserialize(p, ctx);
    } catch (Exception e) {
        throw new RuntimeException("Can not deserialize '" + jobType + "." + paramName + "' job parameter ", e );
    }
}
 

@Override
public ValueProvider<?> deserialize(JsonParser jp, DeserializationContext ctxt)
    throws IOException, JsonProcessingException {
  JsonDeserializer dser =
      ctxt.findRootValueDeserializer(
          checkNotNull(
              innerType, "Invalid %s: innerType is null. Serialization error?", getClass()));
  Object o = dser.deserialize(jp, ctxt);
  return StaticValueProvider.of(o);
}
 

@Override
public LazyEither4<?,?,?,?> deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
  JsonDeserializer ser = ctxt.findRootValueDeserializer(ctxt.getTypeFactory().constructSimpleType(LazyEitherBean.class, new JavaType[0]));
  LazyEitherBean x = (LazyEitherBean)ser.deserialize(p, ctxt);
  if(x.left1!=null){
    return LazyEither4.left1(x.left1);
  }
  if(x.left2!=null){
    return LazyEither4.left2(x.left2);
  }
  if(x.left3!=null){
    return LazyEither4.left3(x.left2);
  }
  return LazyEither4.right(x.right);
}
 

@SuppressWarnings("unchecked")
@Override
public Object deserialize(JsonParser p, DeserializationContext ctxt,
    Object result)
    throws IOException {
  // Ok: must point to START_ARRAY (or equivalent)
  if (!p.isExpectedStartArrayToken()) {
    return handleNonArray(p, ctxt, (Collection<Object>) result);
  }
  // [databind#631]: Assign current value, to be accessible by custom serializers
  p.setCurrentValue(result);

  JsonDeserializer<Object> valueDes = _valueDeserializer;
  final TypeDeserializer typeDeser = _valueTypeDeserializer;
  CollectionReferringAccumulator referringAccumulator =
      (valueDes.getObjectIdReader() == null) ? null :
          new CollectionReferringAccumulator(_containerType.getContentType().getRawClass(), (Collection<Object>) result);

  JsonToken t;
  while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
    try {
      Object value;
      if (t == JsonToken.VALUE_NULL) {
        if (_skipNullValues) {
          continue;
        }
        value = _nullProvider.getNullValue(ctxt);
      } else if (typeDeser == null) {
        value = valueDes.deserialize(p, ctxt);
      } else {
        value = valueDes.deserializeWithType(p, ctxt, typeDeser);
      }
      if (referringAccumulator != null) {
        referringAccumulator.add(value);
      } else {
        ((Collection<Object>) result).add(value);
      }
    } catch (UnresolvedForwardReference reference) {
      if (referringAccumulator == null) {
        throw JsonMappingException
            .from(p, "Unresolved forward reference but no identity info", reference);
      }
      Referring ref = referringAccumulator.handleUnresolvedReference(reference);
      reference.getRoid().appendReferring(ref);
    } catch (Exception e) {
      boolean wrap = (ctxt == null) || ctxt.isEnabled(DeserializationFeature.WRAP_EXCEPTIONS);
      if (!wrap) {
        ClassUtil.throwIfRTE(e);
      }
      throw JsonMappingException.wrapWithPath(e, result, ((Collection<Object>) result).size());
    }
  }
  return result;
}
 

@Override
public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException, JsonProcessingException {
    int took = 0;
    boolean errors = false;
    BulkError error = null;
    int status = -1;
    List<BulkResultItem> items = null;

    String fieldName;
    while ((fieldName = p.nextFieldName()) != null)  {
        switch (fieldName) {
            case "took": {
                took = p.nextIntValue(-1);
                break;
            }
            case "errors": {
                errors = p.nextBooleanValue();
                break;
            }
            case "status": {
                status = p.nextIntValue(-1);
                break;
            }
            case "error": {
                p.nextValue(); // skip to START_OBJECT or VALUE_NULL
                JsonDeserializer<Object> typeDeserializer = ctxt.findNonContextualValueDeserializer(ctxt.constructType(BulkError.class));
                error = (BulkError) typeDeserializer.deserialize(p, ctxt);
                break;
            }
            case "items": {
                if (errors) {
                    items = new ArrayList<>();
                    p.nextValue(); // skip to START_ARRAY
                    p.nextValue(); // skip to START_OBJECT
                    ObjectMapper mapper = (ObjectMapper) p.getCodec();
                    MappingIterator<BulkResultItem> bulkResultItemMappingIterator = mapper.readValues(p, BulkResultItem.class);

                    while (bulkResultItemMappingIterator.hasNext()) {
                        items.add(bulkResultItemMappingIterator.next());
                    }
                }
                break;
            }
        }
    }

    return new BufferedBulkResult(took, errors, error, status, items);
}
 

@Override
public Object deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
    int took = 0;
    boolean errors = false;
    Error error = null;
    int status = -1;
    List<BatchItemResult> items = null;

    String fieldName;
    while ((fieldName = p.nextFieldName()) != null)  {
        switch (fieldName) {
            case "took": {
                took = p.nextIntValue(-1);
                break;
            }
            case "errors": {
                errors = p.nextBooleanValue();
                break;
            }
            case "status": {
                status = p.nextIntValue(-1);
                break;
            }
            case "error": {
                p.nextValue(); // skip to START_OBJECT or VALUE_NULL
                JsonDeserializer<Object> typeDeserializer = ctxt.findNonContextualValueDeserializer(ctxt.constructType(Error.class));
                error = (Error) typeDeserializer.deserialize(p, ctxt);
                break;
            }
            case "items": {
                if (errors) {
                    items = new ArrayList<>();
                    p.nextValue(); // skip to START_ARRAY
                    p.nextValue(); // skip to START_OBJECT
                    ObjectMapper mapper = (ObjectMapper) p.getCodec();
                    MappingIterator<BatchItemResult> batchResultItemMappingIterator = mapper.readValues(p, BatchItemResult.class);

                    while (batchResultItemMappingIterator.hasNext()) {
                        items.add(batchResultItemMappingIterator.next());
                    }
                }
                break;
            }
        }
    }

    return new BatchResult(took, errors, error, status, items);
}
 

@Override
protected T _deserializeEntries(JsonParser p, DeserializationContext ctxt)
    throws IOException, JsonProcessingException
{
    final KeyDeserializer keyDes = _keyDeserializer;
    final JsonDeserializer<?> valueDes = _valueDeserializer;
    final TypeDeserializer typeDeser = _valueTypeDeserializer;

    ImmutableMap.Builder<Object, Object> builder = createBuilder();
    for (; p.currentToken() == JsonToken.FIELD_NAME; p.nextToken()) {
        // Must point to field name now
        String fieldName = p.currentName();
        Object key = (keyDes == null) ? fieldName : keyDes.deserializeKey(fieldName, ctxt);
        // And then the value...
        JsonToken t = p.nextToken();
        // 28-Nov-2010, tatu: Should probably support "ignorable properties" in future...
        Object value;            
        if (t == JsonToken.VALUE_NULL) {
            if (!_skipNullValues) {
                value = _nullProvider.getNullValue(ctxt);
                // 14-Sep-2015, tatu: As per [datatype-guava#52], avoid exception due to null
                // TODO: allow reporting problem via a feature, in future?
                if (value != null) {
                    builder.put(key, value);
                }
            }
            continue;
        }
        if (typeDeser == null) {
            value = valueDes.deserialize(p, ctxt);
        } else {
            value = valueDes.deserializeWithType(p, ctxt, typeDeser);
        }
        builder.put(key, value);
    }
    // No class outside of the package will be able to subclass us,
    // and we provide the proper builder for the subclasses we implement.
    @SuppressWarnings("unchecked")
    T map = (T) builder.build();
    return map;
}
 

@Override
public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
    JsonDeserializer<Object> deserializer = ctxt.findRootValueDeserializer(ctxt.constructType(byte[].class));
    byte[] bytes = (byte[]) deserializer.deserialize(p, ctxt);
    return deserialize(bytes);
}
 

@Override
public Collection<Object> deserialize(JsonParser p, DeserializationContext ctxt,
                                      Collection<Object> result)
        throws IOException {
    // Ok: must point to START_ARRAY (or equivalent)
    if (!p.isExpectedStartArrayToken()) {
        return result;
    }
    // [databind#631]: Assign current value, to be accessible by custom serializers
    p.setCurrentValue(result);

    JsonDeserializer<Object> valueDes = _valueDeserializer;
    final TypeDeserializer typeDeser = _valueTypeDeserializer;
    CollectionReferringAccumulator referringAccumulator =
            (valueDes.getObjectIdReader() == null) ? null :
                    new CollectionReferringAccumulator(_containerType.getContentType().getRawClass(), result);

    JsonToken t;
    while ((t = p.nextToken()) != JsonToken.END_ARRAY) {
        try {
            Object value;
            if (t == JsonToken.VALUE_NULL) {
                if (_skipNullValues) {
                    continue;
                }
                value = _nullProvider.getNullValue(ctxt);
            } else if (typeDeser == null) {
                value = valueDes.deserialize(p, ctxt);
            } else {
                value = valueDes.deserializeWithType(p, ctxt, typeDeser);
            }
            if (referringAccumulator != null) {
                referringAccumulator.add(value);
            } else {
                result.add(value);
            }
        } catch (UnresolvedForwardReference reference) {
            if (referringAccumulator == null) {
                throw JsonMappingException
                        .from(p, "Unresolved forward reference but no identity info", reference);
            }
            ReadableObjectId.Referring ref = referringAccumulator.handleUnresolvedReference(reference);
            reference.getRoid().appendReferring(ref);
        } catch (Exception e) {
            boolean wrap = (ctxt == null) || ctxt.isEnabled(DeserializationFeature.WRAP_EXCEPTIONS);
            if (!wrap) {
                ClassUtil.throwIfRTE(e);
            }
            throw JsonMappingException.wrapWithPath(e, result, result.size());
        }
    }
    return result;
}