MongoDB学习(二)MongoDBJava增删查改

相关资料 1、MongoDB for Java的驱动包 https://github.com/mongodb/mongo-java-driver/downloads 2、在线文档 http://www.mongodb.org/display/DOCS/Java+Language+Center 操作 1、查询某张表（在MongoDB中称之为集合）的所有数据 Java代码DBTest.java pack

相关资料

1、MongoDB for Java的驱动包

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

2、在线文档

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

操作

1、查询某张表（在MongoDB中称之为集合）的所有数据

Java代码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"));
}
}
}

运行结果：

2、对指定DBCollection集合的CRUD操作

Java代码

DBUtil.java

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
* @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;

/**

* 对指定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);
}
/**
* 删除
* @param obj
*/
public static void delete(DBObject obj){
DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");
coll.remove(obj);
}
/**
* 查询
*/
public static void query(){
DBCollection coll=DBUtil.getDBCollection("dbtest", "emp");
// 查询集合中所有的数据
DBCursor cur = coll.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'uname'和'upwd'的数据
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("-----------------------修改后-------------------");
query();

//删除
delete(new BasicDBObject("uname","teddy"));
System.out.println("-----------------------删除后-------------------");
query();
}
}

运行效果：

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