Java操作MongoDB模糊查詢和分頁查詢

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); 記錄總數查詢：count()，返回查詢總數。 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

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();
            // 與目標數據庫能夠建立的最大connection數量爲50 
            builder.connectionsPerHost(50);  
            // 如果當前所有的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); 
            // 一個線程訪問數據庫的時候，在成功獲取到一個可用數據庫連接之前的最長等待時間爲2分鐘 
            // 這裏比較危險，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 
            // 故這裏設置的maxWaitTime應該足夠大，以免由於排隊線程過多造成的數據庫訪問失敗 
            builder.maxWaitTime(1000*60*2);  
            // 與數據庫建立連接的timeout設置爲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);
    }
 
}