mongodb- Java API 增刪改操作

package com.x.mongodb;

import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.bson.types.ObjectId;
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBObject;
import com.mongodb.Mongo;
import com.mongodb.MongoException;
public final class MongoDBUtil {

private static final String HOST = "127.0.0.1";

private static final String dbName = "test";

private static Mongo mongo;

private static DB db;

static {
    try {
        mongo = new Mongo(HOST);
        db = mongo.getDB(dbName);
        // db.authenticate(username, passwd)
    } catch (UnknownHostException e) {
        e.printStackTrace();
    } catch (MongoException e) {
        e.printStackTrace();
    }
}

private MongoDBUtil() {
}

/**
 * 添加操作
 * <br>------------------------------<br>
 * @param map
 * @param collectionName
 */
public static void add(Map<String, Object> map, String collectionName) {
    DBObject dbObject = new BasicDBObject(map);
    getCollection(collectionName).insert(dbObject);
}

/**
 * 添加操作
 * <br>------------------------------<br>
 * @param list
 * @param collectionName
 */
public static void add(List<Map<String, Object>> list, String collectionName) {
    for (Map<String, Object> map : list) {
        add(map, collectionName);
    }
}

/**
 * 刪除操作
 * <br>------------------------------<br>
 * @param map
 * @param collectionName
 */
public static void delete(Map<String, Object> map, String collectionName) {
    DBObject dbObject = new BasicDBObject(map);
    getCollection(collectionName).remove(dbObject);
}

/**
 * 刪除操作,根據主鍵
 * <br>------------------------------<br>
 * @param id            
 * @param collectionName
 */
public static void delete(String id, String collectionName) {
    Map<String, Object> map = new HashMap<String, Object>();
    map.put("_id", new ObjectId(id));
    delete(map, collectionName);
}

/**
 * 刪除全部
 * <br>------------------------------<br>
 * @param collectionName
 */
public static void deleteAll(String collectionName) {
    getCollection(collectionName).drop();
}

/**
 * 修改操作</br>
 * 會用一個新文檔替換現有文檔,文檔key結構會發生改變</br>
 * 比如原文檔{"_id":"123","name":"zhangsan","age":12}當根據_id修改age 
 * value為{"age":12}新建的文檔name值會沒有,結構發生了改變
 * <br>------------------------------<br>
 * @param whereMap      
 * @param valueMap      
 * @param collectionName
 */
public static void update(Map<String, Object> whereMap, Map<String, Object> valueMap, String collectionName) {
    executeUpdate(collectionName, whereMap, valueMap, new UpdateCallback(){
        public DBObject doCallback(DBObject valueDBObject) {
            return valueDBObject;
        }
    });
} 

/**
 * 修改操作,使用$set修改器</br>
 * 用來指定一個鍵值,如果鍵不存在,則自動創建,會更新原來文檔, 不會生成新的, 結構不會發生改變
 * <br>------------------------------<br>
 * @param whereMap      
 * @param valueMap      
 * @param collectionName
 */
public static void updateSet(Map<String, Object> whereMap, Map<String, Object> valueMap, String collectionName) {
    executeUpdate(collectionName, whereMap, valueMap, new UpdateCallback(){
        public DBObject doCallback(DBObject valueDBObject) {
            return new BasicDBObject("$set", valueDBObject);
        }
    });
} 

/**
 * 修改操作,使用$inc修改器</br>
 * 修改器鍵的值必須為數字</br>
 * 如果鍵存在增加或減少鍵的值, 如果不存在創建鍵
 * <br>------------------------------<br>
 * @param whereMap      
 * @param valueMap      
 * @param collectionName
 */
public static void updateInc(Map<String, Object> whereMap, Map<String, Integer> valueMap, String collectionName) {
    executeUpdate(collectionName, whereMap, valueMap, new UpdateCallback(){
        public DBObject doCallback(DBObject valueDBObject) {
            return new BasicDBObject("$inc", valueDBObject);
        }
    });
} 

/**
 * 修改
 * <br>------------------------------<br>
 * @param collectionName
 * @param whereMap
 * @param valueMap
 * @param updateCallback
 */
private static void executeUpdate(String collectionName, Map whereMap, Map valueMap, UpdateCallback updateCallback) {
    DBObject whereDBObject = new BasicDBObject(whereMap);
    DBObject valueDBObject = new BasicDBObject(valueMap);
    valueDBObject = updateCallback.doCallback(valueDBObject);
    getCollection(collectionName).update(whereDBObject, valueDBObject);
}

interface UpdateCallback {

    DBObject doCallback(DBObject valueDBObject);
}

/**
 * 獲取集合(表)
 * <br>------------------------------<br>
 * @param collectionName
 * @return
 */
public static DBCollection getCollection(String collectionName) {
    return db.getCollection(collectionName);
}

}</pre>