mongodb 配置多线程 mongodb是多线程吗

  主要功能：对mongodb的集合做增删改查。

    项目的运行环境：tomcat6、jdk8。

    所用技术：jsp/servlet、前端bootstrap。

    mongodb：personmap。

mongodb工具类：

    定义一个MongoDBUtil的枚举类，枚举类中定义一个instance实例。

    MongoDB工具类 Mongo实例代表了一个数据库连接池，即使在多线程的环境中，一个Mongo实例对我们来说已经足够。
    注意Mongo已经实现了连接池，并且是线程安全的。
    设计为单例模式， 因 MongoDB的Java驱动是线程安全的，对于一般的应用，只要一个Mongo实例即可。
    Mongo有个内置的连接池（默认为10个） 对于有大量写和读的环境中，为了确保在一个Session中使用同一个DB时，DB和DBCollection是绝对线程安全的

public enum MongoDBUtil {
    /**
     * 定义一个枚举的元素，它代表此类的一个实例
     */
    instance;
}

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    在MongoDBUtil类中，定义一个MongoClient对象，并根据IP和端口获得该对象。

private MongoClient mongoClient;
    static {
        System.out.println("===============MongoDBUtil初始化========================");
        // 从配置文件中获取属性值
        String ip = "localhost";
        int port = 27017;
        instance.mongoClient = new MongoClient(ip, port);
    }

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     根据MongoClient对象，得到MongoDataBase对象和MongoConnection<Document>对象。

1 /**
 2      * 获取DB实例 - 指定DB
 3      * 
 4      * @param dbName
 5      * @return
 6      */
 7     public MongoDatabase getDB(String dbName) {
 8         if (dbName != null && !"".equals(dbName)) {
 9             MongoDatabase database = mongoClient.getDatabase(dbName);
10             return database;
11         }
12         return null;
13     }
14     /**
15      * 获取collection对象 - 指定Collection
16      * 
17      * @param collName
18      * @return
19      */
20     public MongoCollection<Document> getCollection(String dbName, String collName) {
21         if (null == collName || "".equals(collName)) {
22             return null;
23         }
24         if (null == dbName || "".equals(dbName)) {
25             return null;
26         }
27         MongoCollection<Document> collection = mongoClient.getDatabase(dbName).getCollection(collName);
28         return collection;
29     }

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     工具类的查询、插入、更新、删除方法。

1 /**条件查询*/
 2     public MongoCursor<Document> find(MongoCollection<Document> coll, Bson filter) {
 3         if(null!=filter){
 4             return coll.find(filter).iterator();
 5         }else{
 6             return coll.find().iterator();
 7         }
 8     }
 9     /**插入一条数据*/
10     public void insert(MongoCollection<Document> coll,Document doc){
11         coll.insertOne(doc);
12     }
13     
14     /**更新一条数据*/
15     public void update(MongoCollection<Document> coll,Document querydoc,Document updatedoc){
16         coll.updateMany(querydoc, updatedoc);
17     }
18 
19     /**删除一条数据*/
20     public void delete(MongoCollection<Document> coll,Document doc){
21         coll.deleteMany(doc);
22     }

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 项目中的增删改查：

    插入：对应MongoDB中脚本的db.getCollection('person').insert({"name":"ryan1","age":21})

1 String name = request.getParameter("name");
 2     Double age = Double.valueOf(request.getParameter("age"));
 3     
 4     String dbName = "personmap";
 5         String collName = "person";
 6         MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
 7         
 8         Document doc = new Document();
 9         doc.put("name", name);
10         doc.put("age", age);
11         MongoDBUtil.instance.insert(coll, doc);
12         
13         PrintWriter out = response.getWriter();
14         out.write("insert success!");
15 
16 插入功能的servlet

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1 <div class="panel    panel-warning" style="width:20%">
 2     <div class="panel-heading">删除文档</div>
 3     <div class="panel-body">
 4         <form action="InsertPerson">
 5             <input type="text" name="name" class="form-control" placeholder="name" aria-describedby="basic-addon1">
 6             <br/>
 7             <input type="text" name="age" class="form-control" placeholder="age" aria-describedby="basic-addon1">
 8             <br/>
 9             <button type="submit" class="btn btn-default">插入</button>
10         </form>
11     </div>
12 </div>
13 
14 插入功能的jsp

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    更新：对应MongoDB中脚本的db.getCollection('person').update({"name":"ryan1"}{"$set":{"age":22}})

1 String queryname = request.getParameter("queryname");
 2     Double updateage = Double.valueOf(request.getParameter("updateage"));
 3     
 4     String dbName = "personmap";
 5     String collName = "person";
 6     MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
 7         
 8     Document querydoc = new Document();
 9     querydoc.put("name", queryname);
10 
11     Document updatedoc = new Document();
12     updatedoc.put("name", queryname);
13     updatedoc.put("age", updateage);
14                 
15     MongoDBUtil.instance.update(coll, querydoc , new Document("$set",updatedoc));
16         
17         PrintWriter out = response.getWriter();
18         out.write("update success!");
19 
20 更新功能的servlet

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1 <div class="panel    panel-warning" style="width:20%">
 2     <div class="panel-heading">根据name更新age</div>
 3     <div class="panel-body">
 4         <form action="UpdatePerson">
 5             <input type="text" name="queryname" class="form-control" placeholder="queryname" aria-describedby="basic-addon1">
 6             <br/>
 7             <input type="text" name="updateage" class="form-control" placeholder="updateage" aria-describedby="basic-addon1">
 8             <br/>
 9             <button type="submit" class="btn btn-default">更新</button>
10     </form>
11     </div>
12 </div>
13 
14 更新功能的jsp

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    删除：对应MongoDB中脚本的db.getCollection('person').remove({"name":"ryan1"})

1 String name = request.getParameter("name");
 2     
 3     String dbName = "personmap";
 4     String collName = "person";
 5     MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
 6         
 7     Document doc = new Document();
 8     doc.put("name", name);
 9 
10     MongoDBUtil.instance.delete(coll, doc);
11         
12     PrintWriter out = response.getWriter();
13     out.write("delete success!");
14 
15 删除功能的servlet

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1 <div class="panel    panel-warning" style="width:20%">
 2     <div class="panel-heading">删除文档</div>
 3     <div class="panel-body">
 4         <form action="DeletePerson">
 5             <input type="text" name="name" class="form-control" placeholder="name" aria-describedby="basic-addon1">
 6             <br/>
 7             <button type="submit" class="btn btn-default">删除</button>
 8         </form>
 9     </div>
10 </div>
11 
12 删除功能的jsp

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    查找：对应MongoDB中脚本的db.getCollection('person').find({})

1 String dbName = "personmap";
 2     String collName = "person";
 3     MongoCollection<Document> coll = MongoDBUtil.instance.getCollection(dbName, collName);
 4         
 5     List<Person> personList = new ArrayList<Person>();
 6     // 查询所有
 7     //Bson filter = Filters.eq("name", "ryan1");
 8     Bson filter = null;
 9     MongoCursor<Document> cursor = MongoDBUtil.instance.find(coll, filter);
10     while(cursor.hasNext()){
11         Document tempdoc = cursor.next();
12         Person person = new Person();
13         person.set_id(tempdoc.get("_id").toString());
14         person.setName(tempdoc.get("name").toString());
15 person.setAge(Double.valueOf(tempdoc.get("age").toString()));
16             personList.add(person);
17     }
18         
19     Gson gson = new Gson();
20         
21     PrintWriter out = response.getWriter();
22     out.write(gson.toJson(personList));
23 
24 查找功能的servlet

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1 <div class="panel panel-warning" style="width:50%">
 2     <div class="panel-heading">查找全部数据</div>
 3     <div class="panel-body">
 4     <table data-toggle="table" 
 5                data-url="FindPerson"
 6                data-classes="table table-hover table-condensed"
 7                data-striped="true">
 8         <thead>
 9             <tr>
10                 <th class="col-xs-2" data-field="_id">_id</th>
11                 <th class="col-xs-2" data-field="name">name</th>
12                 <th class="col-xs-2" data-field="age">age</th>
13             </tr>
14         </thead>
15     </table>
16     </div>
17 </div>
18 
19 查找功能的jsp

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