MongoDB学习笔记（一）

package cn.lcw.mongo.db;

import java.net.UnknownHostException;
import java.util.Iterator;
import java.util.Set;

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

public class ConnectToMangoDB {

    public static void main(String[] args) throws Exception {
        
        Mongo m = null;  
        DB db = null;  
        try {  
            //Mongo(p1, p2):p1=>IP地址     p2=>端口  
            m = new Mongo("127.0.0.1", 27017);  
            //根据mongodb数据库的名称获取mongodb对象  
            db = m.getDB("testlcw");  
            //校验用户密码是否正确  
            if (!db.authenticate("lcw", "lcw".toCharArray())){  
                System.out.println("连接MongoDB数据库,校验失败！");  
            }else{  
                System.out.println("连接MongoDB数据库,校验成功！");  
                  
                db.requestStart();  
                //获取集合名称  
                Set<String> colNameSet = db.getCollectionNames();  
                Iterator<String> colNameItr = colNameSet.iterator();  
                while(colNameItr.hasNext()){  
                    String colName = colNameItr.next();  
                    System.out.println("数据集合的名称："+colName);  
                }  
                //获取集合对象  
                DBCollection dbCol = db.getCollection("ADMIN1352528239201");  
                if(dbCol != null){  
                    //获取集合大小  
                    Integer colSize = (Integer) dbCol.getStats().get("size");  
                    System.out.println("数据集大小为[单位：B]："+colSize);  
                }  
                db.requestDone();  
            }  
        } catch (UnknownHostException e) {  
            e.printStackTrace();  
        } catch (MongoException e) {  
            e.printStackTrace();  
        }  
        //mongodb连接关闭  
        finally{  
            if (null != m) {  
                if (null != db) {  
                    // 结束Mongo数据库的事务请求  
                    try {  
                        db.requestDone();  
                    } catch(Exception e) {  
                        e.printStackTrace();  
                    }  
                }  
                try  
                {  
                    m.close();  
                } catch(Exception e1) {  
                    e1.printStackTrace();  
                }  
                m = null;  
            }  
        }  
    }  
}