MongoDB學習（二）MongoDB Java增刪查改

• 相關資料

1、MongoDB for Java的驅動包

　　https://github.com/mongodb/mongo-java-driver/downloads

2、線上文檔

     http://www.mongodb.org/display/DOCS/Java+Language+Center

 

• 操作

1、查詢某張表（在MongoDB中稱之為集合）的所有資料

Java代碼DBTest.java

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;/** * 查詢指定資料庫指定DBCollection集合中的所有資料 * @author archie2010 * * since 2012-9-29 下午10:40:21 */public class DBTest {    public static void main(String[] args) throws UnknownHostException,            MongoException {        /**           Mongo執行個體代表了一個資料庫連接池         * Mongo mg = new Mongo("localhost");           Mongo mg = new Mongo("localhost", 27017);         */        Mongo mg = new Mongo();        // 擷取名為“dbtest”的資料庫物件        DB db = mg.getDB("dbtest");        // 查詢該庫中所有的集合 (相當於表)        for (String name : db.getCollectionNames()) {            System.out.println("Collection Name: " + name);        }        DBCollection users = db.getCollection("emp");        // 查詢集合中所有的資料        DBCursor cur = users.find();        System.out.println("Record Count:" + cur.count());        while (cur.hasNext()) {            DBObject object = cur.next();            System.out.println(object);            // 取出對象中列表為欄位名為'uname'和'upwd'的資料            System.out.println("uname:" + object.get("uname") + "\tupwd:"                    + object.get("upwd"));        }    }}

運行結果：

2、對指定DBCollection集合的CRUD操作

Java代碼

DBUtil.java

 

package com.archie.mongodb;import java.net.UnknownHostException;import com.mongodb.DB;import com.mongodb.DBCollection;import com.mongodb.Mongo;/** * 獲得DBCollection集合的工具類 * @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;        /**     * 獲得DBCollection對象     * @param dbName     * @param colName     * @return     */    public static DBCollection getDBCollection(String dbName,String colName){        if(mg==null){            try {                mg=new Mongo();            } catch (UnknownHostException e) {                e.printStackTrace();            }        }        if(db==null){            db=mg.getDB(dbName);        }        return db.getCollection(colName);    }}

CRUDTest.java

package com.archie.mongodb;import com.mongodb.BasicDBObject;import com.mongodb.DBCollection;import com.mongodb.DBCursor;import com.mongodb.DBObject;/** * 對指定DBCollection集合的CRUD操作 * @author archie2010 * * since 2012-9-29 下午10:51:24 */public class CRUDTest {    /**     * 增加     * @param obj     */    public static void add(DBObject obj){        DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");        coll.insert(obj);    }    /**     * 刪除     * @param obj     */    public static void delete(DBObject obj){        DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");        coll.remove(obj);    }    /**     * 查詢     */    public static void query(){        DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");        // 查詢集合中所有的資料        DBCursor cur = coll.find();        System.out.println("Record Count:" + cur.count());        while (cur.hasNext()) {            DBObject object = cur.next();            System.out.println(object);            // 取出對象中列表為'uname'和'upwd'的資料            System.out.println("uname:" + object.get("uname") + "\tupwd:"                    + object.get("upwd")+"\t_id:"+object.get("_id"));        }    }    /**     * 修改     */    public static void modify(DBObject orig,DBObject update){        DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");        coll.update(orig, update, true, false);    }    public static void main(String[] args) {        DBObject empObj=new BasicDBObject();        empObj.put("uname", "teddy");        empObj.put("upwd", "123456");        //添加        add(empObj);        query();                        DBObject updateObj=new BasicDBObject();        updateObj.put("uname", "teddy");        updateObj.put("upwd", "3333");        //更新        modify(new BasicDBObject("uname","teddy"),updateObj);        System.out.println("-----------------------修改後-------------------");        query();                //刪除        delete(new BasicDBObject("uname","teddy"));        System.out.println("-----------------------刪除後-------------------");        query();    }}

運行效果：

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