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Java操作MongoDB模糊查詢和分頁查詢

 更新時間:2016年04月29日 10:13:49   投稿:lijiao  
這篇文章主要介紹了Java操作MongoDB模糊查詢和分頁查詢的相關(guān)資料,需要的朋友可以參考下

本文實例為大家分享了Java操作MongoDB模糊查詢和分頁查詢,供大家參考,具體內(nèi)容如下

模糊查詢條件:
1、完全匹配
Pattern pattern = Pattern.compile("^name$", Pattern.CASE_INSENSITIVE);
2、右匹配
Pattern pattern = Pattern.compile("^.*name$", Pattern.CASE_INSENSITIVE);
3、左匹配
Pattern pattern = Pattern.compile("^name.*$", Pattern.CASE_INSENSITIVE);
4、模糊匹配
Pattern pattern = Pattern.compile("^.*name8.*$", Pattern.CASE_INSENSITIVE);
記錄總數(shù)查詢:
count(),返回查詢總數(shù)。
查詢記錄排序:
BasicDBObject sort = new BasicDBObject();
sort.put("name",1);
1、表示正序;-1.表示倒序
分頁查詢:
skip(),跳過多少條記錄
limit(),返回多少條記錄

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();
      // 與目標(biāo)數(shù)據(jù)庫能夠建立的最大connection數(shù)量為50 
      builder.connectionsPerHost(50); 
      // 如果當(dāng)前所有的connection都在使用中,則每個connection上可以有50個線程排隊等待 
      builder.threadsAllowedToBlockForConnectionMultiplier(50); 
      // 一個線程訪問數(shù)據(jù)庫的時候,在成功獲取到一個可用數(shù)據(jù)庫連接之前的最長等待時間為2分鐘 
      // 這里比較危險,如果超過maxWaitTime都沒有獲取到這個連接的話,該線程就會拋出Exception 
      // 故這里設(shè)置的maxWaitTime應(yīng)該足夠大,以免由于排隊線程過多造成的數(shù)據(jù)庫訪問失敗 
      builder.maxWaitTime(1000*60*2); 
      // 與數(shù)據(jù)庫建立連接的timeout設(shè)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);
    }
  }
   
  /**
   * 記錄總數(shù)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");
  }
   
   
  /**
   * 模糊查詢
   * 
   * @param db
   * @param name
   */
  public static void query(DB db,String name){
    DBCollection dbColl = db.getCollection(name);
    //完全匹配
    //Pattern pattern = Pattern.compile("^name$", Pattern.CASE_INSENSITIVE);
    //右匹配
    //Pattern pattern = Pattern.compile("^.*name$", Pattern.CASE_INSENSITIVE);
    //左匹配
    //Pattern pattern = Pattern.compile("^name.*$", Pattern.CASE_INSENSITIVE);
    //模糊匹配
    Pattern pattern = Pattern.compile("^.*name8.*$", Pattern.CASE_INSENSITIVE);
    BasicDBObject query = new BasicDBObject();
    query.put("name",pattern);
    BasicDBObject sort = new BasicDBObject();
    // 1,表示正序; -1,表示倒序
    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模糊查詢和分頁查詢的實現(xiàn)代碼,希望對大家的學(xué)習(xí)有所幫助。

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