第1关：Java 操作 MongoDB 数据库（一）

package step1;
import java.util.function.Consumer;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.ArrayList;
import java.util.List;
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.FindIterable;
import com.mongodb.Block;
public class Mongoconnect{
    public static void main( String args[] ){
        Logger log = Logger.getLogger("org.mongodb.driver");
        log.setLevel(Level.OFF);          //屏蔽带时间的输出
        try{
            //在下面补充代码，连接到mongodb服务
            /********* Begin *********/
            MongoClient mongoClient = new MongoClient("localhost",27017);     
            MongoDatabase mongoDatabase = mongoClient.getDatabase("databaseName");
            /********* End *********/
            //在下面补充代码，创建集合test1
            /********* Begin *********/
            mongoDatabase.createCollection("test");

            /********* End *********/
            //在下面补充代码，获取集合test1
            /********* Begin *********/
            MongoCollection<Document> collection = mongoDatabase.getCollection("test");
            /********* End *********/
            //在下面补充代码，插入编程要求中的数据到集合test1
            /********* Begin *********/
            Document document1 = new Document();
            document1.append("_id", "1");
            document1.append("name", "Xiaoming");
            document1.append("sex", "man");
            document1.append("age", 21);
            List<Document> documents = new ArrayList<Document>();
            documents.add(document1);
            collection.insertMany(documents); 

            /********* End *********/
            //在Begin和End之间补充代码，请勿修改代码的原本框架
            FindIterable<Document> iter = collection.find();
            iter.forEach(new Consumer<Document>() {
                @Override
                public void accept(Document document) {
                    System.out.println(document.toJson());
                }
            });
            Document doc = collection.find().first();
            collection.deleteOne(doc);
        }catch (Exception e) {
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }
    }
}

第二关

package step2;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Consumer;
import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.FindIterable;
import com.mongodb.Block;  
import com.mongodb.client.model.Filters;
import com.mongodb.client.MongoCursor;
public class Mongo{
    public static void main( String args[] ){
        Logger log = Logger.getLogger("org.mongodb.driver");  
        log.setLevel(Level.OFF);          //屏蔽带时间的输出
        try{ 
            //仿照第一关，连接数据库mydb2并选择集合test2
            /********* Begin *********/ 
            MongoClient mongoClient =new MongoClient("localhost");
            MongoDatabase mongoDatabase = mongoClient.getDatabase("mydb2");
            MongoCollection collection =mongoDatabase.getCollection("test2");
            //在下面补充代码，插入文档到集合test2中
            /********* Begin *********/ 
            Document document1=new Document();  
         document1.append("_id","1");  
         document1.append("name","Xiaoming");  
         document1.append("sex","man");  
         document1.append("age",21);
         Document document2=new Document();  
         document2.append("_id","2");  
         document2.append("name","Xiaohong");  
         document2.append("sex","woman");  
         document2.append("age",20);
         Document document3=new Document();      
         document3.append("_id","3");  
         document3.append("name","Xiaoliang");  
         document3.append("sex","man");  
         document3.append("age",22);  
         List documents =new ArrayList();  
         documents.add(document1);  
         documents.add(document2);  
         documents.add(document3);  
         collection.insertMany(documents);  
            /********* End *********/
            //在Begin和End之间补充代码，请勿修改代码的原本框架
            FindIterable<Document> iter = collection.find();
            System.out.println("文档插入结果如下：");
            iter.forEach(new Block<Document>() {
              public void apply(Document _doc) {
                System.out.println(_doc.toJson());
              }
            });
            //在下面补充代码，更新 Xiaohong 的信息为23岁
            /********* Begin *********/ 
            collection.updateMany(Filters.eq("name", "Xiaohong"),new Document("$set",new Document("age",23)));
            /********* End *********/
            //在Begin和End之间补充代码，请勿修改代码的原本框架
            FindIterable<Document> findIterable = collection.find();  
            MongoCursor<Document> mongoCursor = findIterable.iterator(); 
            System.out.println("更新后文档内容如下：");
            while(mongoCursor.hasNext()){  
            System.out.println(mongoCursor.next());  
            };
            //在下面补充代码，删除Xiaoliang的信息
            /********* Begin *********/ 
            collection.deleteMany(Filters.eq("name","Xiaoliang"));  
            /********* End *********/ 
            //在Begin和End之间补充代码，请勿修改代码的原本框架
            FindIterable<Document> iter1 = collection.find();
            System.out.println("删除信息后的文档内容为：");
            
            iter1.forEach(new Consumer<Document>() {
                @Override
                public void accept(Document document) {
                    System.out.println(document.toJson());
                }
            });

            collection.drop();
        }catch (Exception e) {
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }
    }
}