Java操作Mongodb数据库实现数据的增删查改功能示例

package io.mogo;import java.util.Map;import org.apache.commons.lang3.StringUtils;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.WriteResult;public class App{  private static final String host = "localhost";  private static final int port = 27017;  private static final String userName = "";  private static final String password = "";  private static final String dataBaseName = "test";  private static DB db;  public static void main( String[] args ) throws Exception  {    System.out.println( "Hello World!" );    connMongoDB();    find("person", "name", "xiaoming");    DBObject newObj = new BasicDBObject();    newObj.put("name", "xiaoming");    newObj.put("desc", "i am xiaoming");    update("person", "name", "xiaoming", newObj);    find("person", "name", "xiaoming");  }  public static void connMongoDB() throws Exception {    Mongo mongo = new Mongo(host, port);    db = mongo.getDB(dataBaseName);    if (!StringUtils.isEmpty(userName) || !StringUtils.isEmpty(password)) {      db.authenticate(userName, password.toCharArray());    }  }  public static void find(String tableName, String key, String value){   DBObject obj = new BasicDBObject();   obj.put(key, value);   DBCollection dbCollection = db.getCollection(tableName);   DBCursor dbCursor = dbCollection.find(obj);   while(dbCursor.hasNext()){     Map map = (Map)dbCursor.next();     System.out.println(map);   }  }  public static boolean delete(String tableName, String key, String value){    DBObject obj = new BasicDBObject();    obj.put(key, value);    DBCollection dbCollection = db.getCollection(tableName);    WriteResult result = dbCollection.remove(obj);    if(result.getN() > 0){      System.out.println("删除数据成功！");      return true;    }else{      return false;    }  }  public static boolean insert(String tableName, DBObject obj){    DBCollection dbCollection = db.getCollection(tableName);    long num = dbCollection.count();    dbCollection.insert(obj);    if(dbCollection.count() - num > 0){      System.out.println("插入数据成功！");      return true;    }else{      return false;    }  }  public static boolean update(String tableName, String key, String value, DBObject newValue){    DBObject obj = new BasicDBObject();    obj.put(key, value);    DBCollection dbCollection = db.getCollection(tableName);    DBObject oldValue = dbCollection.findOne(obj);    WriteResult result = dbCollection.update(oldValue, newValue);    if(result.getN() > 0){      System.out.println("数据更新成功！");      return true;    }else      return false;  }}