mongodb-java-driver基本用法

1、先下载mongodb-java-driver 目前最新版本是2.9.3

2、下面是基本的CRUD示例代码:

 package com.cnblogs.yjmyzz.cache.test;

 import com.google.gson.Gson;
 import com.mongodb.BasicDBObject;
 import com.mongodb.DB;
 import com.mongodb.DBCollection;
 import com.mongodb.DBCursor;
 import com.mongodb.DBObject;
 import com.mongodb.Mongo;
 import com.mongodb.util.JSON;

 import java.net.UnknownHostException;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;

 import org.junit.Test;

 public class TestMongoDriver {

     @Test
     public void testCRUD() throws UnknownHostException {
         // 连接到mongodb
         Mongo mongo = new Mongo("localhost", 27017);

         // 打开数据库test
         DB db = mongo.getDB("test");

         // 遍历所有集合的名字
         Set<String> colls = db.getCollectionNames();
         for (String s : colls) {
             System.out.println(s);
             // 先删除所有Collection(类似于关系数据库中的"表")
             if (!s.equals("system.indexes")) {
                 db.getCollection(s).drop();
             }
         }

         // 取得集合emp(若：emp不存在，mongodb将自动创建该集合)
         DBCollection coll = db.getCollection("emp");

         // delete all
         DBCursor dbCursor = coll.find();
         for (DBObject dbObject : dbCursor) {
             coll.remove(dbObject);
         }

         // create
         BasicDBObject doc = new BasicDBObject("name", "杨俊明").append("sex", "男")
                 .append("address",
                         new BasicDBObject("postcode", "201202").append(
                                 "street", "田林路888号").append("city", "上海"));
         coll.insert(doc);

         // retrieve
         BasicDBObject docFind = new BasicDBObject("name", "杨俊明");
         DBObject findResult = coll.findOne(docFind);
         System.out.println(findResult);

         // update
         doc.put("sex", "MALE");// 把sex属性从"男"，改成"MALE"
         coll.update(docFind, doc);
         findResult = coll.findOne(docFind);
         System.out.println(findResult);

         coll.dropIndexes();// 先删除所有索引
         // create index
         coll.createIndex(new BasicDBObject("name", 1)); // 1代表升序

         // 复杂对象
         UserData userData = new UserData("jimmy", "123456");
         Set<String> pets = new HashSet<String>();
         pets.add("cat");
         pets.add("dog");
         Map<String, String> favoriteMovies = new HashMap<String, String>();
         favoriteMovies.put("dragons", "Dragons II");
         favoriteMovies.put("avator", "Avator I");
         userData.setFavoriteMovies(favoriteMovies);
         userData.setPets(pets);
         userData.setBirthday(getDate(1990, 5, 1));
         BasicDBObject objUser = new BasicDBObject("key", "jimmy").append(
                 "value", toDBObject(userData));
         coll.insert(objUser);
         System.out.println(coll.findOne(objUser));
     }

     /**
      * 将普通Object对象转换成mongodb的DBObject对象
      *
      * @param obj
      * @return
      */
     private DBObject toDBObject(Object obj) {
         Gson gson = new Gson();
         String json = gson.toJson(obj);
         return (DBObject) JSON.parse(json);
     }

     /**
      * 获取指定日期
      *
      * @param year
      * @param month
      * @param day
      * @return
      */
     private Date getDate(int year, int month, int day) {
         Calendar calendar = Calendar.getInstance();
         calendar.clear();
         calendar.set(year, month - 1, day);
         return calendar.getTime();

     }

 }

其中，为了演示复杂对象的持久化，类UserData定义如下：

package com.cnblogs.yjmyzz.cache.test;

import java.io.Serializable;
import java.util.Date;
import java.util.Map;
import java.util.Set;

public class UserData implements Serializable {

    private static final long serialVersionUID = -4770493237851400594L;
    private String userName;
    private String password;
    private Set<String> pets;
    private Map<String, String> favoriteMovies;
    private Date birthday;

    public UserData() {
    }

    public UserData(String userName, String passWord) {
        this.userName = userName;
        this.password = passWord;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Set<String> getPets() {
        return pets;
    }

    public void setPets(Set<String> pets) {
        this.pets = pets;
    }

    public Map<String, String> getFavoriteMovies() {
        return favoriteMovies;
    }

    public void setFavoriteMovies(Map<String, String> favoriteMovies) {
        this.favoriteMovies = favoriteMovies;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }
}

运行效果如下：

emp
system.indexes
{ "_id" : { "$oid" : "53d34795744ec171e7f6980a"} , "name" : "杨俊明" , "sex" : "男" , "address" : { "postcode" : "201202" , "street" : "田林路888号" , "city" : "上海"}}
{ "_id" : { "$oid" : "53d34795744ec171e7f6980a"} , "name" : "杨俊明" , "sex" : "MALE" , "address" : { "postcode" : "201202" , "street" : "田林路888号" , "city" : "上海"}}
{ "_id" : { "$oid" : "53d34796744ec171e7f6980b"} , "key" : "jimmy" , "value" : { "userName" : "jimmy" , "password" : "123456" , "pets" : [ "cat" , "dog"] , "favoriteMovies" : { "dragons" : "Dragons II" , "avator" : "Avator I"} , "birthday" : "May 1, 1990 12:00:00 AM"}}

延伸阅读：
mondodb-java-driver 官方在线文档

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