MongoDB学习(二)MongoDB Java增删查改

package com.archie.mongodb;

import java.net.UnknownHostException;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoException;

/**

* 查询指定数据库指定DBCollection集合中的所有数据
* @author archie2010
*
* since 2012-9-29 下午10:40:21
*/
public class DBTest {
  public static void main(String[] args) throws UnknownHostException,
  MongoException {
  /**
Mongo实例代表了一个数据库连接池
* Mongo mg = new Mongo("localhost");
Mongo mg = new Mongo("localhost", 27017);
*/
  Mongo mg = new Mongo();

  // 获取名为“dbtest”的数据库对象
  DB db = mg.getDB("dbtest");
  // 查询该库中所有的集合 (相当于表)
  for (String name : db.getCollectionNames()) {
  System.out.println("Collection Name: " + name);
  }
  DBCollection users = db.getCollection("emp");
  // 查询集合中所有的数据
  DBCursor cur = users.find();
  System.out.println("Record Count:" + cur.count());
  while (cur.hasNext()) {
  DBObject object = cur.next();
  System.out.println(object);
  // 取出对象中列表为字段名为'uname'和'upwd'的数据
  System.out.println("uname:" + object.get("uname") + "\tupwd:"
  + object.get("upwd"));
  }
  }
}

package com.archie.mongodb;

import java.net.UnknownHostException;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.Mongo;

/**
* 获得DBCollection集合的工具类
* @author archie2010
*
* since 2012-9-29 下午10:54:42
*/
public class DBUtil {

  public static Mongo mg=null; 
  public static DB db=null; 
  public static DBCollection collection;

  /**
* 获得DBCollection对象
* @param dbName
* @param colName