Java 如何避免Mongodb中重复的对象条目？

现在在我的项目中，我正在使用Play framework（JAVA）和Mongodb。我的集合中有两个字段，分别是哈希和地址。请注意，地址字段是一个对象

我的收藏如下：

db.hashed.find()
{ "_id" : ObjectId("55f04cd0d4c68ef1211e6ee4"), "hash" : "1axuhWcqKB", "address" : { "floor" : 0, "block" : "5", "city" : "Mumbai", "state" : "ABC", "pincode" : 0, "latitude" : "77.6876", "longitude" : "13.57558", "hash" : "1axuhWcqKB" } }
{ "_id" : ObjectId("55f04cd1d4c68ef1211e6ee6"), "hash" : "1ay4P407qF", "address" : { "floor" : 0, "block" : "5", "city" : "Mumbai", "state" : "ABC", "pincode" : 0, "latitude" : "77.6876", "longitude" : "13.57558", "hash" : "1ay4P407qF" } }
{ "_id" : ObjectId("55f04cd2d4c68ef1211e6ee8"), "hash" : "1ayDn3Zemh",    "address" : { "floor" : 0, "block" : "5", "city" : "Mumbai", "state" : "ABC", "pincode" : 0, "latitude" : "77.6876", "longitude" : "13.57558", "hash" : "1ayDn3Zemh" } } 

现在我在想，如何避免重复的地址条目，这显然不应该被插入到数据库中。我尝试在地址字段上执行ensureindex，但看起来它并不能解决这个问题

> db.users.ensureIndex({"address" : 1},{unique: true})
{
"createdCollectionAutomatically" : false,
"numIndexesBefore" : 2,
"numIndexesAfter" : 2,
"note" : "all indexes already exist",
"ok" : 1
}

希望有人能帮我解决这个问题

我认为问题在于地址子对象中的“散列”属性。这三排都不同。这就是为什么mongodb不将它们视为重复密钥的原因。下面是我的工作示例（虽然没有播放框架，但它并没有改变这一点）：

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谢谢你的回复。那么这是否意味着我将永远无法在数据库级别检查重复项，看起来我只能通过代码来完成这项工作？也许你可以对此发表评论：）你可以通过将索引更改为：users.ensureIndex（“{address.floor:1，address.block:1，address.city:1，“+”address.state:1，address.pincode:1，address.latitude:1，“{name:\”unique\u address\”，unique:true}”）来检查重复项；你的意思是在数据库级别上类似这样的东西？db.ensureIndex（“{address.floor:1，address.block:1，address.city:1，“address.state:1，address.pincode:1，address.latitude:1”，“address.latitude:1}”，“{name:\“unique\U address\”，unique:true}”）。如果我遗漏了什么，请告诉我。顺便说一句，再次感谢您提供的信息性答案。在mongo命令行客户端中，只需使用以下命令：db.users.ensureIndex（{“address.floor”：1，“address.block”：1，“address.city”：1，“address.pincode”：1，“address.latitude”：1，“address.longitude”：1}，{name:“unique_address”，unique:true}）

import java.util.LinkedHashMap;
import java.util.Map;

import org.jongo.Jongo;
import org.jongo.MongoCollection;

import com.mongodb.DB;
import com.mongodb.MongoClient;

public class MongodbTest {
    public static void main(String[] args) throws Exception {
        String tableName = "UniqueAddressTest";
        DB mdb = new MongoClient("localhost:27017").getDB(tableName);
        Jongo jdb = new Jongo(mdb);
        MongoCollection users = jdb.getCollection(tableName);
        users.drop();
        users.ensureIndex("{address:1}", "{unique:true}");
        Map<String, Object> user1 = new LinkedHashMap<String, Object>();
        Map<String, Object> address1 = new LinkedHashMap<String, Object>();
        address1.put("floor", 0);
        address1.put("block", "5");
        address1.put("city", "Mumbai");
        address1.put("state", "ABC");
        address1.put("pincode", 0);
        address1.put("latitude", "77.6876");
        address1.put("longitude", "13.57558");
        address1.put("hash", "1axuhWcqKB");
        user1.put("address", address1);
        users.insert(user1);
        users.insert(user1); // Here is where duplicate key exception happens
    }
}

    users.ensureIndex("{address.floor:1, address.block:1, address.city:1, " +
            "address.state:1, address.pincode:1, address.latitude:1, " +
            "address.longitude:1}", "{name:\"unique_address\", unique:true}");