JAVA操作MongoDB数据库实例教程

MongoClient mongoclient=new MongoClient("127.0.0.1",27017);

mongoclient.close();

//获取链接对象，参数1为url，参数2为端口号
MongoClient mongoclient=new MongoClient("127.0.0.1",27017);
//获取所有库名的迭代器
MongoIterable<String> list= mongoclient.listDatebaseNames();
for(String str:list){
    System.out.println(str);//查看所有库名
}

//获取链接对象，参数1为url，参数2为端口号
MongoClient mongoclient=new MongoClient("127.0.0.1",27017);
//获取库对象，参数为库名
MongoDatabase db=mongoclient.getDatabase("school");
//获取当前库对象的所有集合名的迭代器
MongoIterable<String> list=db.getlistCollectionNames();
for(String str:list){
    System.out.println(str);//获取所有集合名
}
//获取集合对象，参数为集合名
MongoCollention<Document> collection=db.getCollection("student");

//获取集合对象
MongoCollection<Document> collection = db.getCollection("student");
//新增时创建一个Docuement对象，以键值对的形式传入内容
Document document = new Document();
document.put("name", "张三");
document.put("age", 99);
document.put("sex", "男");
//添加一条数据，没有返回值
collection.insertOne(document);
//新增多条数据,传入一个document集合
collection.insertMany(null);

 
//修改条件
Bson eq = Filters.eq("name","张三");
//修改匹配到的第一条
UpdateResult updateOne = collection.updateOne(
	eq, new Document("$set",new Document("age",50)));
//修改匹配的多条
collection.updateMany(eq, null);

AcknowledgedUpdateResult{matchedCount=0, modifiedCount=0, upsertedId=null}

//条件
Bson eq = Filters.eq("name","张三");
//删除一条符合的
DeleteResult deleteOne = collection.deleteOne(eq);
//删除 所有符合条件的
DeleteResult deleteMany = collection.deleteMany(eq);

AcknowledgedDeleteResult{deletedCount=0}

//无条件全查
FindIterable<Document> find = collection.find();
//带条件查询
Bson eq = Filters.regex("name", "张");
FindIterable<Document> find = collection.find(eq);

//全查
FindIterable<Document> find = collection.find();
//创建一个实体类集合准备接收结果
List<Student>  slist = new ArrayList<Student>();
//获取结果集迭代器对象	
MongoCursor<Document> iterator = find.iterator();
while(iterator.hasNext()) {
	Student s =  new Student();
	Document next = iterator.next();
	s.setSname(next.getString("name"));
	s.setSsex(next.getString("sex"));
	s.setSid(next.getInteger("sid"));	
    //将结果添加至实体类集合
	slist.add(s);
}