Java操作MongoDB隱約查詢和分頁查詢

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本文實例為年夜家分享了Java操作MongoDB隱約查詢和分頁查詢，供年夜家參考，詳細內容以下

隱約查詢前提：
1、完整婚配
Pattern pattern = Pattern.compile("^name$", Pattern.CASE_INSENSITIVE);
2、右婚配
Pattern pattern = Pattern.compile("^.*name$", Pattern.CASE_INSENSITIVE);
3、左婚配
Pattern pattern = Pattern.compile("^name.*$", Pattern.CASE_INSENSITIVE);
4、隱約婚配
Pattern pattern = Pattern.compile("^.*name8.*$", Pattern.CASE_INSENSITIVE);
記載總數查詢：
count()，前往查詢總數。
查詢記載排序：
BasicDBObject sort = new BasicDBObject();
sort.put("name",1);
1、表現正序；－1.表現倒序
分頁查詢：
skip()，跳過量少筆記錄
limit()，前往若干筆記錄

代碼實例:

package com.what21.mongodb.demo;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;
 
import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientOptions;
import com.mongodb.MongoCredential;
import com.mongodb.ServerAddress;
 
public class OperateDemo2 {
 
  /**
   * @return
   * @throws Exception
   */
  public static MongoClient getMongoClient()throws Exception{
    try {
      //===================================================//
      List<ServerAddress> serverList = new ArrayList<ServerAddress>();
      serverList.add(new ServerAddress("192.168.18.85", 27017));
      //===================================================//
      List<MongoCredential> mcList = new ArrayList<MongoCredential>();
      String username = "root";
      String database = "demo";
      char[] password = "root123".toCharArray();
      mcList.add(MongoCredential.createCredential(username, database,password));
      //===================================================//
      MongoClientOptions.Builder builder = MongoClientOptions.builder();
      // 與目的數據庫可以或許樹立的最年夜connection數目為50 
      builder.connectionsPerHost(50); 
      // 假如以後一切的connection都在應用中，則每一個connection上可以有50個線程列隊期待 
      builder.threadsAllowedToBlockForConnectionMultiplier(50); 
      // 一個線程拜訪數據庫的時刻，在勝利獲得到一個可用數據庫銜接之前的最長期待時光為2分鐘 
      // 這裡比擬風險，假如跨越maxWaitTime都沒有獲得到這個銜接的話，該線程就會拋出Exception 
      // 故這裡設置的maxWaitTime應當足夠年夜，以避免因為列隊線程過量形成的數據庫拜訪掉敗 
      builder.maxWaitTime(1000*60*2); 
      // 與數據庫樹立銜接的timeout設置為1分鐘 
      builder.connectTimeout(1000*60*1);  
      //===================================================//
      MongoClientOptions mco = builder.build(); 
      return new MongoClient(serverList, mcList, mco);
    } catch (Exception e) {
      throw e;
    }
  }
   
  /**
   * @param dbname
   * @return
   * @throws Exception
   */
  public static DB getDB(String dbname) throws Exception{
    return getMongoClient().getDB(dbname);
  }
   
  /**
   * @param db
   */
  public static void collections(DB db){
    Set<String> colls = db.getCollectionNames();
    for (String collName : colls) {
      System.out.println(collName);
    }
  }
   
  /**
   * 記載總數查詢
   * 
   * @param db
   * @param name
   */
  public static void count(DB db,String name){
    DBCollection dbColl = db.getCollection(name);
    int count = dbColl.find().count();
    System.out.println("共有： " + count + "個");
  }
   
   
  /**
   * 隱約查詢
   * 
   * @param db
   * @param name
   */
  public static void query(DB db,String name){
    DBCollection dbColl = db.getCollection(name);
    //完整婚配
    //Pattern pattern = Pattern.compile("^name$", Pattern.CASE_INSENSITIVE);
    //右婚配
    //Pattern pattern = Pattern.compile("^.*name$", Pattern.CASE_INSENSITIVE);
    //左婚配
    //Pattern pattern = Pattern.compile("^name.*$", Pattern.CASE_INSENSITIVE);
    //隱約婚配
    Pattern pattern = Pattern.compile("^.*name8.*$", Pattern.CASE_INSENSITIVE);
    BasicDBObject query = new BasicDBObject();
    query.put("name",pattern);
    BasicDBObject sort = new BasicDBObject();
    // 1,表現正序； －1,表現倒序
    sort.put("name",1);
    DBCursor cur = dbColl.find(query).sort(sort);
    int count = 0;
    while (cur.hasNext()) {
      DBObject obj = cur.next();
      System.out.print("name=" + obj.get("name"));
      System.out.print(",email=" + obj.get("email"));
      System.out.println(",passwd=" + obj.get("passwd"));
      count ++;
    }
    System.out.println("共有： " + count + "個");
  }
   
 
  /**
   * 分頁查詢
   * 
   * @param db
   * @param name
   * @param start
   * @param pageSize
   */
  public static void page(DB db,String name,int start,int pageSize){
    DBCollection dbColl = db.getCollection(name);
    BasicDBObject sort = new BasicDBObject();
    sort.put("name",1);
    DBCursor cur = dbColl.find().sort(sort).skip(start).limit(pageSize);;
    int count = 0;
    while (cur.hasNext()) {
      DBObject obj = cur.next();
      System.out.print("name=" + obj.get("name"));
      System.out.print(",email=" + obj.get("email"));
      System.out.println(",passwd=" + obj.get("passwd"));
      count ++;
    }
    System.out.println("共有： " + count + "個");
  }
  /**
   * @param args
   * @throws Exception 
   */
  public static void main(String[] args) throws Exception {
    DB db = getDB("demo");
    collections(db);
    String name = "users";
    System.out.println("count()=================================================");
    count(db,name);
    System.out.println("query()=================================================");
    query(db,name);
    System.out.println("page()=================================================");
    page(db,name,10, 10);
  }
 
}

以上就是Java操作MongoDB隱約查詢和分頁查詢的完成代碼，願望對年夜家的進修有所贊助。