MongoDB的對象的建立

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  1 package com.voice.db;  2   3 import com.mongodb.DB;  4 import com.mongodb.DBCollection;  5 import com.mongodb.Mongo;  6 import com.mongodb.MongoClient;  7 import com.mongodb.MongoClientOptions;  8 import com.mongodb.ReadPreference;  9 import com.mongodb.ServerAddress; 10 import com.mongodb.WriteConcern; 11  12  13 public class MongoDB { 14  15     private Mongo wMongodb; 16      17     private static MongoDB instance = null; 18      19     private static synchronized MongoDB GetInstance() 20     { 21         if(!isInstanceAlive()) 22         { 23             instance = new MongoDB(); 24         } 25         return instance; 26     } 27  28     /** 29      * 判斷資料庫是否處於串連狀態中 30      * @return true:串連中<br/> 31      *        false:已斷開 32      */ 33     private static boolean isInstanceAlive() { 34         boolean retBool = false; 35         try { 36             // 嘗試訪問一次資料庫 37             DBCollection col = instance.wMongodb.getDB("database_name").getCollection("table_name"); 38             col.count(); 39             retBool = true; 40         } catch (Exception e) { 41             try { 42                 instance.wMongodb.close(); 43             } catch (Exception ex) {} 44         } 45         return retBool; 46     } 47      48     private MongoDB() 49     { 50         try { 51             MongoClientOptions.Builder voicedbBuilder = MongoClientOptions.builder(); 52             voicedbBuilder.connectTimeout(3000); 53             voicedbBuilder.socketTimeout(6000); 54             voicedbBuilder.autoConnectRetry(true); 55             voicedbBuilder.connectionsPerHost(5); 56             voicedbBuilder.readPreference(ReadPreference.secondaryPreferred()); 57             voicedbBuilder.socketKeepAlive(true); 58             MongoClientOptions voicedbOptions = voicedbBuilder.build(); 59  60 //          wMongodb = new MongoClient(new ServerAddress("172.16.10.15", 27020),voicedbOptions); 61             wMongodb = new MongoClient(new ServerAddress("localhost", 27020),voicedbOptions); 62              63             DB db = wMongodb.getDB("db_name"); 64 //            DB db = wMongodb.getDB("olacloud_internal"); 65             db.authenticate("id", "id".toCharArray()); 66             db.setWriteConcern(WriteConcern.SAFE); 67         } catch (Exception e) { 68             // TODO Auto-generated catch block 69             e.printStackTrace(); 70         } 71          72     } 73  74     /** 75      * 擷取資料庫連接 76      * @return 已經串連的資料庫 77      */ 78     public static DB getDB() { 79         DB db = MongoDB.GetInstance().wMongodb.getDB("db_name"); 80 //        DB db = MongoDB.GetInstance().wMongodb.getDB("olacloud_internal"); 81         return db; 82     } 83  84     /** 85      * 擷取table的串連 86      * @param tableName table名 87      * @return table串連 88      */ 89     public static DBCollection getDBCollection(String tableName) { 90         DB db = MongoDB.getDB(); 91         DBCollection col = db.getCollection(tableName); 92         return col; 93     } 94      95     /** 96      * 關閉當前的Mongodb串連 97      */ 98     public static void close() { 99         if (instance != null) {100             instance.wMongodb.close();101         }102     }103 104 }

 

MongoDB的對象的建立