您正在混合Java驱动程序Aggregates方法与Spring Aggregation方法.
此外，$addFields仍然是not supported在 Spring 蒙戈。
您必须使用以下聚合。

import static org.springframework.data.mongodb.core.aggregation.Aggregation.*;
Aggregation myDocAggr = newAggregation(
       match(Criteria.where("metaId.ref.uuid").is(someUUID)), 
       group("uuid").max("version").as("version"),
       lookup("simple","execId.ref.uuid","uuid","simple"),
       unwind("simple"),
       new AggregationOperation(){ 
         @Override 
         public Document toDocument(AggregationOperationContext aoc) {
            return new Document("$addFields",new Document("metaId.ref.name","$simple.name"));
         }
      }
)
List<Document> mydocumentList=mongoTemplate.aggregate(myDocAggr,"myDocument",Document.class).getMappedResults();

尽管$addFields不被spring mongo支持，你可以自己实现它：

import org.bson.Document;
import org.springframework.data.mongodb.core.aggregation.*;
import java.util.LinkedHashMap;
import java.util.Map;

public class AddFieldsOperation implements FieldsExposingAggregationOperation {
    private Map<String, Object> fields = new LinkedHashMap<>();

    public AddFieldsOperation(String field, AggregationExpression expression) {
        addField(field, expression);
    }

    public AddFieldsOperation addField(String field, AggregationExpression expression) {
        this.fields.put(field, expression.toDocument(Aggregation.DEFAULT_CONTEXT));
        return this;
    }

    @Override
    public Document toDocument(AggregationOperationContext context) {
        Document doc = new Document();
        fields.forEach(doc::append);
        return new Document("$addFields", doc);
    }

    @Override
    public boolean inheritsFields() {
        return true;
    }

    @Override
    public ExposedFields getFields() {
        final String[] fieldsArray = fields.keySet().toArray(new String[0]);
        return ExposedFields.synthetic(Fields.fields(fieldsArray));
    }

并像这样使用它：

...
ArithmeticOperators.Add value1 = ArithmeticOperators.Add.valueOf(0);
ArithmeticOperators.Add value2 = ArithmeticOperators.Add.valueOf(0);
AddFieldsOperation addFields
            = new AddFieldsOperation("value1", value1)
            .addField("value2", value2);
pipeline.add(addFields);
...
Add value1PlusValue2 = Add.valueOf("$value1").add("$value2");
...

希望它能帮助到一些人。

从'spring-data-mongodb'的3.0版本开始，创建AddField聚合实际上是非常容易的。您可以使用AddFieldsOperationBuilder。
在下面的示例中，我为objectId字段添加了一个名为_id的字符串ID字段。字符串字段idString可以在查找聚合中使用。
示例：

AddFieldsOperation addFieldsOperation = Aggregation.addFields().addFieldWithValue("idString", ConvertOperators.ToString.toString("$_id")).build();