POJOs as documents in mongodb

Question

I am trying to save entity as documents in Mongodb and tried to create Codec for it . And it does not seem to work . I tried Morphia but, i am not able to find documentation on adding extra fields into document at runtime using morphia. this would defy the basic purpose of using Mongodb at first place . I initially want my documents to have fixed number of fields that are in POJO . and during the run of application the number of fields should change

Can any one suggest me what should i do

Answer 1

I don't know if this is good solution but here is what i did . If you are not using Morphia for Mongodb . and you want you POJO entity to be serialized . you can do this like code show below . but you have to maintain the setters call sequence if you want the data to be organized below are two class which gives some hint

package com.mongodbtest.entities;

 import java.io.Serializable;

 import org.bson.Document;

 import org.bson.BsonDocument;
 import org.bson.BsonInt32;
  import org.bson.BsonNumber;
 import org.bson.BsonString;

public class User extends BsonDocument {

/**
     * 
     */
private static final long serialVersionUID = -9167404209850672507L;
// private String _id;
private BsonString name;
private BsonString email;
private BsonString address;
private BsonInt32 phno;

public User(String name, String email, StringBuilder address, Number phno) {
    super();
    this.name = new BsonString(name);
    this.email = new BsonString(email);
    this.address = new BsonString(address.toString());
    this.phno = new BsonInt32(phno.intValue());
}

public User() {
}

public BsonString getName() {
    return this.name;
}

public void setName(String name) {
    this.name = new BsonString(name);
    this.append("name", this.name);

}

public BsonString getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = new BsonString(email);
    this.append("email", this.email);
}

public BsonString getAddress() {
    return address;
}

public void setAddress(StringBuilder address) {
    this.address = new BsonString(address.toString());
    this.append("address", this.address);
}

public BsonInt32 getPhno() {
    return phno;
}

public void setPhno(Number phno) {
    this.phno = new BsonInt32(phno.intValue());
    this.append("phno", this.phno);
}

}

and Class that serializes this will be like this

package com.mongodb.sample;

import org.bson.BsonDocument;
import org.bson.Document;

import com.mogodbsample.config.DBconfig;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodbtest.entities.User;

public class Firstmongoaccess {

public static void main(String... args) {
    MongoDatabase dataase = DBconfig.getdatabase();
    MongoCollection<User> collection = dataase.getCollection("users",  User.class);

    User u1 = new User();
    u1.setAddress(new StringBuilder("something street bangalore 356322"));
    u1.setName("xxxxxx");
    u1.setEmail("[email protected]");
    u1.setPhno(3263433);

    collection.insertOne(u1);
    MongoCursor<? extends BsonDocument> cursor = collection.find().iterator();
    try {
        while (cursor.hasNext()) {
            System.out.println(cursor.next().toJson());
        }
    } finally {
        cursor.close();
    }

}
}