MongoDB java操做的一些記錄

/**
 * 工具類
 */
package com.topsoft.websites.sun.db;

import java.net.UnknownHostException;
import java.util.logging.Logger;


import com.mongodb.DB;
import com.mongodb.MongoClient;
import com.mongodb.ServerAddress;

/**
 * @author sunyameng
 *2014-2-26下午2:50:29
 */
public class DBClient {
	private Logger logger=Logger.getLogger(DBClient.class.getName());
	private static DBClient instance=new DBClient();
	private MongoClient mongoClient;
	private DB db;
	private DBClient(){}
	public DB getDB(String ip,Integer port,String dbName,String user,String pwd){
		if(port==null) port=27017;
		try {
			mongoClient = new MongoClient(new ServerAddress(ip, port));
		    db = mongoClient.getDB(dbName);
            boolean auth = db.authenticate(user, pwd.toCharArray());
		    if(auth){
		    	logger.info("user or password is wrong.");
		    	close();
		    	return null;
		    }
		} catch (UnknownHostException e) {
			logger.info("Cann't find host "+e.getCause().toString());
			close();
		}
		return db;
	}
	public void close(){
		if(mongoClient!=null)
			mongoClient.close();
	}
	public static DBClient getInstance(){
		return instance;
	}
}

一些測試遇到的問題

/**
 * 
 */
package com.topsoft.websites.sun.test;

import static com.mongodb.util.MyAsserts.assertTrue;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

import com.mongodb.*;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

import com.topsoft.websites.sun.db.DBClient;

/**
 * @author sunyameng
 *2014-2-26下午3:08:46
 */
@RunWith(JUnit4.class)
public class DBClientTest {
	private static DBClient dbClient;
	private static DB db;
	@BeforeClass
	public static void setUpBeforeClass() {
		dbClient=DBClient.getInstance();
		db=dbClient.getDB("127.0.0.1",27017,"topsites", "admin", "");
	}
		
	@AfterClass
	public static void tearDownAfterClass(){
		dbClient.close();
	}
	
	@Test
	public void testGetDB() {
		assertNotNull(db);
	}
	/*
	 * get a list of collections
	 */
	@Test
    @Ignore
	public void getListCollections(){
		Set<String> collections=db.getCollectionNames();
		assertNotNull(collections);
		for(String s:collections){
			System.out.println(s);
		}
	}

	@Test
	public void testFind(){
		DBCollection coll=db.getCollection("site");
        DBObject query = new BasicDBObject("s_name", "河南拓普");
        List<DBObject> list=coll.find(query).toArray();
        assertTrue(list.size()>0);
        DBObject obj=list.get(0);
        System.out.println(obj);
    }
	@Test
    public void testSave(){
        DBCollection coll=db.getCollection("site");
        DBObject query = new BasicDBObject("name", "tom").append("age",20);
        coll.save(query);
    }
    private BasicDBObject copy(DBObject dbObject){
        if(dbObject==null) return null;
        return new BasicDBObject((BasicDBObject)dbObject);
    }
    @Test
    @Ignore
    public void testFindAndInsert(){
        DBCollection coll=db.getCollection("site");
        DBObject query = new BasicDBObject("name", "tom");
        //查找的記錄包含_id字段，在保存或插入的時候應該複製一份dbobject,不然會報can't save partial object錯誤
        List<DBObject> list=coll.find(query).toArray();
        DBObject obj=list.get(0);
        //複製一份
        BasicDBObject copyObj=copy(obj);
        copyObj.put("name", "amorn");
        System.out.println(copyObj);
        boolean result=true;
        try{
            //save方法和insert方法的區別：若是已經存在一個_id和要保存的同樣，則更新它；
            //若是不存在，則插入一條；而insert方法則會insert方法則會插入一條新的紀錄，前提是插入的記錄中不包含_id
            coll.save(copyObj);
        }catch (Exception e){
            result=false;
            e.printStackTrace();
        }
        assertTrue(result);
    }
    @Test
    public void testFindAndUpdate(){
        DBCollection coll=db.getCollection("site");
        DBObject query = new BasicDBObject("name", "tom");
        List<DBObject> list=coll.find(query).toArray();
        DBObject obj=list.get(0);
        //複製一份
        BasicDBObject copyObj=copy(obj);
        copyObj.put("name", "mh370");
        boolean result=true;
        try{
            //upsert參數設置爲true,表示若是不存在則插入一條，若是存在直接更新；multi設置爲true,表示更新多行
            //此處的更新會重寫該條記錄，即擦除以前的紀錄，_id保持不變
            //此處更新不能使用多行更新，會報錯multi update only works with $ operators
            coll.update(query, copyObj);

            //第二種更新方式，就是更新指定字段，此種方法能夠使用多行更新,此處只作一個實例
            //BasicDBObject updateObj=new BasicDBObject("$set",new BasicDBObject("name","mh370"));
            //coll.update(query, updateObj,true,true);
        }catch (Exception e){
            result=false;
            e.printStackTrace();
        }
        assertTrue(result);
    }
	@Test
	@Ignore
	public void testCursor(){
		DBCollection coll=db.getCollection("site");
		DBCursor cursor=coll.find();
		assertNotNull(cursor);
		try{
			while(cursor.hasNext()){
				System.out.println(cursor.next());
			}
		}finally{
			cursor.close();
		}		
	}
	
	@Test
	@Ignore
	public void testPageQuery(){
		List<DBObject> list=getDBObject(2, 5);
		assertEquals(5,list.size());
		
		for(DBObject obj:list){
			System.out.println(obj.toString());
		}
	}
	
	@Test
	@Ignore
	public void testProjection(){
		DBCollection coll=db.getCollection("demo");
		
		BasicDBObject field=new BasicDBObject("name",1).append("age", 1).append("_id", 0);
		DBCursor cursor=coll.find(null,field);
		assertNotNull(cursor);
		while(cursor.hasNext()){
			System.out.println(cursor.next().toString());
		}
	}
	@Test
    @Ignore
	public void testCondition(){
		String collectionName="site";
		String[] fields=new String[]{"code","parentcode","name"};
		DBObject condition=new BasicDBObject();
		condition.put("name", "河南工商行政管理局");
		DBCollection collection=db.getCollection(collectionName);
		

		List<DBObject> list=find(collection,fields,null,1,2);
		assertNotNull(list);
		for(int i=0;i<list.size();i++){
			DBObject obj=list.get(i);
			System.out.println(obj);
		}
		
	}
	private List<DBObject> getDBObject(int pageNumber,int nPerPage){
		DBCollection coll=db.getCollection("employee");
		DBCursor cursor=coll.find().skip((pageNumber-1)*nPerPage).limit(nPerPage);
		return cursor.toArray();
	}
	
	public List<DBObject> find(DBCollection collection,String[] fields,DBObject condition,Integer pageNumber,Integer nPerPage){
		List<DBObject> result=new ArrayList<DBObject>();
		BasicDBObject field=new BasicDBObject("_id",0);
		for(String f:fields){
			field.append(f, 1);
		}
		if(pageNumber==null||nPerPage==null){
			result=collection.find(condition,field).toArray();
		}else{
			result=collection.find(condition,field).skip((pageNumber-1)*nPerPage).limit(nPerPage).toArray();
		}
		return result;
	}
	
	
	
	
}