MongoDb二

Posted 2021-01-24 暮雪超霸

获取集合的时候，可以传入bean的class文件。来实现数据的绑定。
在这之前。需要自定义一个Codec类。进行数据的转换。

        MongoClient client=new MongoClient(new ServerAddress("127.0.0.1",27017));
        MongoDatabase db=    client.getDatabase("chaoba");
        CodecRegistry codecRegistry=CodecRegistries.fromRegistries(CodecRegistries.fromCodecs(new Chaoba1Codec()));
    MongoCollection<Chaoba1> chaoba1    =db.getCollection("chaoba1",Chaoba1.class).withCodecRegistry(codecRegistry);
//    MongoCursor<Chaoba1> result=chaoba.find().iterator();
//    while(result.hasNext()) {
//        System.out.println(result.next());
//    }
        
        Chaoba1 chaoba =new Chaoba1();
        chaoba.setName("Demo2");
        chaoba1.insertOne(chaoba);

Codec类

package demo2;

import org.bson.BsonReader;
import org.bson.BsonWriter;
import org.bson.codecs.Codec;
import org.bson.codecs.DecoderContext;
import org.bson.codecs.EncoderContext;

public class Chaoba1Codec implements Codec<Chaoba1>{

    @Override
    public void encode(BsonWriter writer, Chaoba1 value, EncoderContext encoderContext) {
        // TODO Auto-generated method stub
        writer.writeStartDocument();
        writer.writeString("name", value.getName());
//        writer.writeString("sex", value.getSex());
        writer.writeEndDocument();
    }

    @Override
    public Class<Chaoba1> getEncoderClass() {
        // TODO Auto-generated method stub
        return Chaoba1.class;
    }

    @Override
    public Chaoba1 decode(BsonReader reader, DecoderContext decoderContext) {
        // TODO Auto-generated method stub
        reader.readStartDocument();
        
        
        Chaoba1 chaoba1=new Chaoba1();
        
        chaoba1.set_id(reader.readObjectId("_id"));
        chaoba1.setName(reader.readString("name"));
//        chaoba1.setSex(reader.readString("sex"));
        reader.readEndDocument();
        return chaoba1;
    }

}