Java操作MongoDB模糊查询和分页查询

本文实例为大家分享了java操作mongodb模糊查询和分页查询，供大家参考，具体内容如下

模糊查询条件：
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);
记录总数查询：
count()，返回查询总数。
查询记录排序：
basicdbobject sort = new basicdbobject();
sort.put("name",1);
1、表示正序；－1.表示倒序
分页查询：
skip()，跳过多少条记录
limit()，返回多少条记录

代码实例:

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();
      // 与目标数据库能够建立的最大connection数量为50 
      builder.connectionsperhost(50); 
      // 如果当前所有的connection都在使用中，则每个connection上可以有50个线程排队等待 
      builder.threadsallowedtoblockforconnectionmultiplier(50); 
      // 一个线程访问数据库的时候，在成功获取到一个可用数据库连接之前的最长等待时间为2分钟 
      // 这里比较危险，如果超过maxwaittime都没有获取到这个连接的话，该线程就会抛出exception 
      // 故这里设置的maxwaittime应该足够大，以免由于排队线程过多造成的数据库访问失败 
      builder.maxwaittime(1000*60*2); 
      // 与数据库建立连接的timeout设置为1分钟 
      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);
    }
  }
   
  /**
   * 记录总数查询
   * 
   * @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 + "个");
  }
   
   
  /**
   * 模糊查询
   * 
   * @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 + "个");
  }
   
 
  /**
   * 分页查询
   * 
   * @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 + "个");
  }
  /**
   * @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模糊查询和分页查询的实现代码，希望对大家的学习有所帮助。