mongo连表查询

sql语句如下：

db.getCollection('user').aggregate([
{
    $lookup: { // 左连接
        from: "message", // 关联到message表
        localField: "thirdId", // user 表关联的字段
        foreignField: "fromId", // message 表关联的字段
        as: "message"
    }
 },
 { 
     $match:{  
         "valid":{$exists:false},
         "message":{$ne: {$size: 0}},
         "message.msgType" : "text"
     }
 }
    ])

对应代码如下：

public List<User> findValid(){
        Aggregation agg = Aggregation.newAggregation(
                Aggregation.match(Criteria.where("valid").exists(false).and("message.msgType").is("text")),
                Aggregation.lookup("message", "thirdId", "fromId", "message")
                );
        AggregationResults<User> result = mongoTemplate.aggregate(agg,"user", User.class);
        List<User> userList = result.getMappedResults();
        log.info("userList.size()   {}", userList.size());
        return userList;
    }