无法在MongoDB中序列化类Java和String是编码的

时间:2013-04-20 19:57:30

标签: java json mongodb

我的简单应用程序假设只使用_iduser之间的映射填充MongoDB。我的密钥(_id)采用JSON格式,其值只有很长。

{
    "_id": {
        "a": "1B2ac",
        "b": "Windows NT 5.2; WOW64; rv:16.0 Ff/6.0"
    },
    "user": 1999129
}

我有几个问题:

问题1:当我尝试插入时,我得到can's serialize class...

Caused by: java.lang.IllegalArgumentException: can't serialize class test.mongo.foo.DummyObject
    at org.bson.BSONEncoder._putObjectField(BSONEncoder.java:234)
    at org.bson.BSONEncoder.putObject(BSONEncoder.java:121)
    at org.bson.BSONEncoder.putObject(BSONEncoder.java:86)
    at com.mongodb.OutMessage.putObject(OutMessage.java:190)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:253)
    at com.mongodb.DBApiLayer$MyCollection.insert(DBApiLayer.java:217)
    at com.mongodb.DBCollection.insert(DBCollection.java:102)
    at     com.test.mongo.foo.DaoImpl.insertRecords(DaoImpl.java:130)

以下是DummyObject(实现Serializable)的课程:

 package test.mongo.foo;

import java.io.Serializable;

public class DummyObject implements Serializable{

    private static final long serialVersionUID = -2715467675581503964L;

    //default constructor
    public DummyObject(){

    }

    private String a;
    private String b;

    public String getA() {
        return a;
    }

    public String getB() {
        return b;
    }

    public void setA(String a) {
        this.a = a;
    }

    public void setB(String b) {
        this.b = b;
    }

}

这是我的DaoImp班级

package test.mongo.foo;
public class DaoImpl extends MongoDAOImpl{

    public int insertRecords(List<DBObject> records) {
        DBCollection coll = getDBCollection();

        Exception e = null;
        try {
            WriteResult res =  coll.insert(records);
            if (res.getError() != null) {
                throw new MongoRuntimeException(res.getError());
            }
            return res.getN();
        } catch (Exception err) {
            e = err;
            throw new MongoRuntimeException(err);
        }
    }

    public static DBObject convertToDBObject(DummyObject obj, long value) {
        DBObject bdbo = new BasicDBObject();
        bdbo.put("_id",obj);
        bdbo.put("user",value);
        return bdbo;
    }
    public static void main(String [] args){
          DummyObject d = new DummyObject();
           d.setA("1B2ac");
           d.setB("Windows NT 5.2; WOW64; rv:16.0 Ff/6.0");
           long val = 1999129;
           List<DBObject> l = new ArrayList<DBObject>();
           l.add(DaoImpl.convertToDBObject(d,val));
           DaoImpl impl = new DaoImpl();
    }
}

问题2:为了避免上述问题,我尝试使用String to String mapping插入记录。虽然我的输入字符串(对于_id)没有被转义,但DBObject在内部转义它并最终写入MongoDB,如下所示:

{
    "_id": {
        \"a\": \"1B2ac\",
        \"b\": \"WindowsNT5.2;WOW64;rv: 16.0Ff/6.0\"
    },
    "user": NumberLong(1999129)
}

INSTEAD OF

{
    "_id": {
        "a": "1B2ac",
        "b": "Windows NT 5.2; WOW64; rv:16.0 Ff/6.0"
    },
    "user": 1999129
}

有关如何解决这两个问题的任何建议?任何指针都非常受欢迎。

1 个答案:

答案 0 :(得分:2)

没关系。在玩了一下之后,我找到了回答我自己的问题。作为JsonObject插入。我将我的DummyObject转换为JsonObject / Object(提示:Json.parse(jstr))

由于 Masti