MongoDB基本用法（增删改高级查询、mapreduce）

分享一下我经常用到的自己写的mongo用法示例

该示例基于当前最新的mongo驱动，版本为mongo-2.10.1.jar,用junit写的单元测试。

 

TestCase.java

 package com.wujintao.mongo;

 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
 import java.util.regex.Pattern;

 import org.junit.Test;

 import com.mongodb.AggregationOutput;
 import com.mongodb.BasicDBList;
 import com.mongodb.BasicDBObject;
 import com.mongodb.BasicDBObjectBuilder;
 import com.mongodb.DB;
 import com.mongodb.DBCollection;
 import com.mongodb.DBCursor;
 import com.mongodb.DBObject;
 import com.mongodb.MapReduceCommand;
 import com.mongodb.MapReduceOutput;
 import com.mongodb.Mongo;
 import com.mongodb.QueryBuilder;
 import com.mongodb.WriteConcern;

 public class TestCase {
        //DBCursor cursor = coll.find(condition).addOption(Bytes.QUERYOPTION_NOTIMEOUT);//设置游标不要超时

     @Test
     /**
      * 获取所有数据库实例
      */
     public void testGetDBS() {
         List dbnames = MongoUtil.getMong().getDatabaseNames();
         for (String dbname : dbnames) {
             System.out.println("dbname:" + dbname);
         }
     }

     @Test
     /**
      * 删除数据库
      */
     public void dropDatabase() {
         MongoUtil.getMong().dropDatabase("my_new_db");
     }

     @Test
     /**
      * 查询所有表名
      */
     public void getAllCollections() {
         Set colls = MongoUtil.getDB().getCollectionNames();
         for (String s : colls) {
             System.out.println(s);
         }
     }

     @Test
     public void dropCollection() {
         MongoUtil.getColl("jellonwu").drop();
     }

     /**
      * 添加一条记录
      */
     @Test
     public void addData() {
         DBCollection coll = MongoUtil.getColl("wujintao");
         BasicDBObject doc = new BasicDBObject();
         doc.put("name", "MongoDB");
         doc.put("type", "database");
         doc.put("count", 1);

         BasicDBObject info = new BasicDBObject();
         info.put("x", 203);
         info.put("y", 102);
         doc.put("info", info);
         coll.insert(doc);
         // 设定write concern，以便操作失败时得到提示
         coll.setWriteConcern(WriteConcern.SAFE);
     }

     @Test
     /**
      * 创建索引
      */
     public void createIndex() {
         MongoUtil.getColl("wujintao").createIndex(new BasicDBObject("i", 1));
     }

     @Test
     /**
      * 获取索引信息
      */
     public void getIndexInfo() {
         List list = MongoUtil.getColl("hems_online").getIndexInfo();
         for (DBObject o : list) {
             System.out.println(o);
         }
     }

     @Test
     /**
      * 添加多条记录
      */
     public void addMultiData() {
         for (int i = 0; i < 100; i++) {
             MongoUtil.getColl("wujintao").insert(
                     new BasicDBObject().append("i", i));
         }

         List docs = new ArrayList();
         for (int i = 0; i < 50; i++) {
             docs.add(new BasicDBObject().append("i", i));
         }
         MongoUtil.getColl("wujintao").insert(docs);
         // 设定write concern，以便操作失败时得到提示
         MongoUtil.getColl("wujintao").setWriteConcern(WriteConcern.SAFE);
     }

     @Test
     /**
      * 查找第一条记录
      */
     public void findOne() {
         DBObject myDoc = MongoUtil.getColl("wujintao").findOne();
         System.out.println(myDoc);
     }

     @Test
     /**
      * 获取表中所有记录条数
      */
     public void count() {
         System.out.println(MongoUtil.getColl("wujintao").getCount());
         System.out.println(MongoUtil.getColl("wujintao").count());
     }

     @Test
     /**
      * 获取查询结果集的记录数
      */
     public void getCount() {
         DBObject query = new BasicDBObject("name", "a");
         long count = MongoUtil.getColl("wujintao").count(query);
         System.out.println(count);
     }

     @Test
     /**
      * 查询所有结果
      */
     public void getAllDocuments() {
         DBCursor cursor = MongoUtil.getColl("wujintao").find();
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     /**
      * 按照一个条件查询
      */
     public void queryByConditionOne() {
         BasicDBObject query = new BasicDBObject();
         query.put("name", "MongoDB");
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query);

         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     /**
      * AND多条件查询,区间查询
      */
     public void queryMulti() {
         BasicDBObject query = new BasicDBObject();
         // 查询j不等于3,k大于10的结果集
         query.put("j", new BasicDBObject("$ne", 3));
         query.put("k", new BasicDBObject("$gt", 10));
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query);
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     /**
      * 区间查询
      * select * from table where i >50
      */
     public void queryMulti2() {
         BasicDBObject query = new BasicDBObject();
         query = new BasicDBObject();
         query.put("i", new BasicDBObject("$gt", 50)); // e.g. find all where i >
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query);
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     /**
      * 区间查询
      * select * from table where 20 < i <= 30
         //比较符
         //"$gt"： 大于
         //"$gte"：大于等于
         //"$lt"： 小于
         //"$lte"：小于等于
         //"$in"： 包含
      */
     public void queryMulti3() {
         BasicDBObject query = new BasicDBObject();
         query = new BasicDBObject();

         query.put("i", new BasicDBObject("$gt", 20).append("$lte", 30));
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query);
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     /**
      * 组合in和and select * from test_Table where (a=5 or b=6) and (c=5 or d = 6)
      */
     public void queryMulti4() {
         BasicDBObject query11 = new BasicDBObject();
         query11.put("a", 1);
         BasicDBObject query12 = new BasicDBObject();
         query12.put("b", 2);
         List orQueryList1 = new ArrayList();
         orQueryList1.add(query11);
         orQueryList1.add(query12);
         BasicDBObject orQuery1 = new BasicDBObject("$or", orQueryList1);

         BasicDBObject query21 = new BasicDBObject();
         query21.put("c", 5);
         BasicDBObject query22 = new BasicDBObject();
         query22.put("d", 6);
         List orQueryList2 = new ArrayList();
         orQueryList2.add(query21);
         orQueryList2.add(query22);
         BasicDBObject orQuery2 = new BasicDBObject("$or", orQueryList2);

         List orQueryCombinationList = new ArrayList();
         orQueryCombinationList.add(orQuery1);
         orQueryCombinationList.add(orQuery2);

         BasicDBObject finalQuery = new BasicDBObject("$and",
                 orQueryCombinationList);
         DBCursor cursor = MongoUtil.getColl("wujintao").find(finalQuery);
     }

     @Test
     /**
      * IN查询
      * if i need to query name in (a,b); just use { name : { $in : ['a', 'b'] } }
      * select * from things where name='a' or name='b'
      * @param coll
      */
     public void queryIn() {
         BasicDBList values = new BasicDBList();
         values.add("a");
         values.add("b");
         BasicDBObject in = new BasicDBObject("$in", values);
         DBCursor cursor = MongoUtil.getColl("wujintao").find(
                 new BasicDBObject("name", in));
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     /**
      * 或查询
      * select * from table where name  = '12' or title = 'p'
      * @param coll
      */
     public void queryOr() {
         QueryBuilder query = new QueryBuilder();
         query.or(new BasicDBObject("name", 12), new BasicDBObject("title", "p"));
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query.get()).addSpecial("$returnKey", "");
         try {
             while (cursor.hasNext()) {
                 System.out.println(cursor.next());
             }
         } finally {
             cursor.close();
         }
     }

     @Test
     public void customQueryField() throws UnknownHostException{
         Mongo mongo = new Mongo("localhost", 27017);
         DB db = mongo.getDB("zhongsou_ad");
         BasicDBObjectBuilder bulder = new BasicDBObjectBuilder();
         bulder.add("times",1);
         bulder.add("aid",1);
         DBCursor cusor =  db.getCollection("ad_union_ad_c_1").find(new BasicDBObject(),bulder.get());
         for (DBObject dbObject : cusor) {
             System.out.println(dbObject);
         }
     }

     @Test
     public void mapReduce() throws UnknownHostException{
         Mongo mongo = new Mongo("localhost", 27017);
         DB db = mongo.getDB("zhongsou_ad");
         /***
          *  book1 = {name : "Understanding JAVA", pages : 100}
          *  book2 = {name : "Understanding JSON", pages : 200}
          *  db.books.save(book1)
          *  db.books.save(book2)
          *  book = {name : "Understanding XML", pages : 300}
          *  db.books.save(book)
          *  book = {name : "Understanding Web Services", pages : 400}
          *  db.books.save(book)
          *  book = {name : "Understanding Axis2", pages : 150}
          *  db.books.save(book)
          *
         var map = function() {
             var category;
             if ( this.pages >= 250 )
                 category = 'Big Books';
             else
                 category = "Small Books";
             emit(category, {name: this.name});
         };
         var reduce = function(key, values) {
             var sum = 0;
             values.forEach(function(doc) {
                 sum += 1;
             });
             return {books: sum};
         };
         var count  = db.books.mapReduce(map, reduce, {out: "book_results"});
          */
         try {

             DBCollection books = db.getCollection("books");

             BasicDBObject book = new BasicDBObject();
             book.put("name", "Understanding JAVA");
             book.put("pages", 100);
             books.insert(book);

             book = new BasicDBObject();
             book.put("name", "Understanding JSON");
             book.put("pages", 200);
             books.insert(book);

             book = new BasicDBObject();
             book.put("name", "Understanding XML");
             book.put("pages", 300);
             books.insert(book);

             book = new BasicDBObject();
             book.put("name", "Understanding Web Services");
             book.put("pages", 400);
             books.insert(book);

             book = new BasicDBObject();
             book.put("name", "Understanding Axis2");
             book.put("pages", 150);
             books.insert(book);

             String map = "function() { "+
                       "var category; " +
                       "if ( this.pages >= 250 ) "+
                       "category = 'Big Books'; " +
                       "else " +
                       "category = 'Small Books'; "+
                       "emit(category, {name: this.name});}";

             String reduce = "function(key, values) { " +
                                      "var sum = 0; " +
                                      "values.forEach(function(doc) { " +
                                      "sum += 1; "+
                                      "}); " +
                                      "return {books: sum};} ";

             MapReduceCommand cmd = new MapReduceCommand(books, map, reduce,
               null, MapReduceCommand.OutputType.INLINE, null);

             MapReduceOutput out = books.mapReduce(cmd);

             for (DBObject o : out.results()) {
              System.out.println(o.toString());
             }
            } catch (Exception e) {
              e.printStackTrace();
            }
     }

     @Test
     public void GroupByManyField() throws UnknownHostException{
         //此方法没有运行成功
         Mongo mongo = new Mongo("localhost", 27017);
         DB db = mongo.getDB("libary");
         DBCollection books = db.getCollection("books");
         BasicDBObject groupKeys = new BasicDBObject();
         groupKeys.put("total", new BasicDBObject("$sum","pages"));

         BasicDBObject condition = new BasicDBObject();
         condition.append("pages", new BasicDBObject().put("$gt", 0));


         String reduce = "function(key, values) { " +
                 "var sum = 0; " +
                 "values.forEach(function(doc) { " +
                 "sum += 1; "+
                 "}); " +
                 "return {books: sum};} ";
         /**
          BasicDBList basicDBList = (BasicDBList)db.getCollection("mongodb中集合编码或者编码")
                    .group(DBObject key,   --分组字段，即group by的字段
                 DBObject cond,        --查询中where条件
                 DBObject initial,     --初始化各字段的值
                 String reduce,        --每个分组都需要执行的Function
                 String finial         --终结Funciton对结果进行最终的处理
          */
         DBObject obj = books.group(groupKeys, condition,  new BasicDBObject(), reduce);
         System.out.println(obj);

         AggregationOutput ouput = books.aggregate(new BasicDBObject("$group",groupKeys));
         System.out.println(ouput.getCommandResult());
         System.out.println(books.find(new BasicDBObject("$group",groupKeys)));
     }


     @Test
     /**
      * 分页查询
      */
     public void pageQuery() {
         DBCursor cursor = MongoUtil.getColl("wujintao").find().skip(0)
                 .limit(10);
         while (cursor.hasNext()) {
             System.out.println(cursor.next());
         }
     }

     /**
      * 模糊查询
      */
     public void likeQuery() {
         Pattern john = Pattern.compile("joh?n");
         BasicDBObject query = new BasicDBObject("name", john);

         // finds all people with "name" matching /joh?n/i
         DBCursor cursor = MongoUtil.getColl("wujintao").find(query);
     }

     @Test
     /**
      * 条件删除
      */
     public void delete() {
         BasicDBObject query = new BasicDBObject();
         query.put("name", "xxx");
         // 找到并且删除，并返回删除的对象
         DBObject removeObj = MongoUtil.getColl("wujintao").findAndRemove(query);
         System.out.println(removeObj);
     }

     @Test
     /**
      * 更新
      */
     public void update() {
         BasicDBObject query = new BasicDBObject();
         query.put("name", "liu");
         DBObject stuFound = MongoUtil.getColl("wujintao").findOne(query);
         stuFound.put("name", stuFound.get("name") + "update_1");
         MongoUtil.getColl("wujintao").update(query, stuFound);
     }


 }

 

这里面涉及到的MongoUtil.java如下：

 package com.wujintao.mongo;

 import java.net.UnknownHostException;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;

 import com.mongodb.DB;
 import com.mongodb.DBCollection;
 import com.mongodb.Mongo;


 /**
  * to see:http://www.mongodb.org/display/DOCS/Java+Driver+Concurrency
  * Mongo工具类:设计为单例模式，每当月份发生变化，数据库连接名称就会发生变化，这是业务规则
  * 因 MongoDB的Java驱动是线程安全的，对于一般的应用，只要一个Mongo实例即可，Mongo有个内置的连接池（池大小默认为10个）。
  * 对于有大量写和读的环境中，为了确保在一个Session中使用同一个DB时，我们可以用以下方式保证一致性：
  *   DB mdb = mongo.getDB('dbname');
  *   mdb.requestStart();
  *   // 业务代码
  *   mdb.requestDone();
  * DB和DBCollection是绝对线程安全的
  * @author wujintao
  */
 public class MongoUtil{

     private static Mongo mongo;
     private static DBCollection coll;
     private static Log log = LogFactory.getLog(MongoUtil.class);
     private static DB db;

     static{
         try {
               MongoOptions options = new MongoOptions();
                       options.autoConnectRetry = true;
                       options.connectionsPerHost = 1000;
                       options.maxWaitTime = 5000;
                       options.socketTimeout = 0;
                       options.connectTimeout = 15000;
                       options.threadsAllowedToBlockForConnectionMultiplier = 5000;
             //事实上，Mongo实例代表了一个数据库连接池，即使在多线程的环境中，一个Mongo实例对我们来说已经足够了
             mongo = new Mongo(new ServerAddress(DBMongoConfig.getHost(),DBMongoConfig.getPort()),options);
             //mongo = new Mongo(DBMongoConfig.getHost(),DBMongoConfig.getPort());
             // or, to connect to a replica set, supply a seed list of members
             // Mongo m = new Mongo(Arrays.asList(new ServerAddress("localhost",
             // 27017),
             // new ServerAddress("localhost", 27018),
             // new ServerAddress("localhost", 27019)));

             // 注意Mongo已经实现了连接池，并且是线程安全的。
             // 大部分用户使用mongodb都在安全内网下，但如果将mongodb设为安全验证模式，就需要在客户端提供用户名和密码：
             // boolean auth = db.authenticate(myUserName, myPassword);
         } catch (UnknownHostException e) {
             log.info("get mongo instance failed");
         }
     }

     public static DB getDB(){
         if(db==null){
             db = mongo.getDB(DBMongoConfig.getDbname());
         }
         return db;
     }


     public static Mongo getMong(){
         return mongo;
     }

     public static DBCollection getColl(String collname){
         return getDB().getCollection(collname);
     }

 }