Mongodb提供了很多的客户端: shell,python, java, node.js...等等.
以 java 为例实现简单的增删改查
在这里我们先封装一个mongodb管理类:
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.bson.Document;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.CreateCollectionOptions;
import com.mongodb.client.result.DeleteResult;
/**
* MongoDB管理类
* @author jiangyuechao
*
*/
public class MongoDBHelper {
static Logger logger = LoggerFactory.getLogger(MongoDBHelper.class);
static String ip = "10.80.18.1";
//10.80.21.41 10.80.18.1
static MongoClient mongoClient = new MongoClient(ip, 27017);
//MongoDatabase实例是不可变的
static MongoDatabase database;
//firstDB
public static void connect(String databaseName){
database = mongoClient.getDatabase(databaseName);
}
public static MongoCollection<Document> getCollection(String collectionName){
//MongoCollection实例是不可变的
if(!collectionExists(collectionName)){
return null;
}
MongoCollection<Document> collection = database.getCollection(collectionName);
return collection;
}
public static boolean collectionExists(final String collectionName) {
boolean collectionExists = database.listCollectionNames()
.into(new ArrayList<String>()).contains(collectionName);
return collectionExists;
/*MongoIterable<String> mongoIterable = database.listCollectionNames();
for (Iterator<String> iterator = mongoIterable.iterator(); iterator.hasNext();) {
String name = iterator.next();
logger.info("name:{}", name);
if(name.equals(collectionName)){
return true;
}
}
return false;*/
}
public static void getAllDocuments(MongoCollection<Document> collection){
MongoCursor<Document> cursor = collection.find().iterator();
try {
while (cursor.hasNext()) {
System.out.println(cursor.next().toJson());
}
} finally {
cursor.close();
}
}
public static String getDocumentFirst(MongoCollection<Document> collection){
Document myDoc = collection.find().first();
return myDoc.toJson();
}
public static void createDocument(MongoCollection<Document> collection,Map<String,Object> map){
System.out.println("--------------------");
map.forEach((k,v)->{ System.out.println("Key : " + k + " Value : " + v);});
}
/**
* 插入一个Document
* @param collection
* @param doc
*/
public static void insertDocument(MongoCollection<Document> collection,Document doc){
collection.insertOne(doc);
}
/**
* 插入多个Document
* @param collection
* @param documents
*/
public static void insertManyDocument(MongoCollection<Document> collection,List<Document> documents){
collection.insertMany(documents);
}
/**
* 显示创建集合
*/
public static void explicitlyCreateCollection(String collectionName){
database.createCollection(collectionName,
new CreateCollectionOptions().capped(false));
}
// 删除集合的所有文档
public static long deleteAllDocument(MongoCollection<Document> collection) {
DeleteResult deleteResult = collection.deleteMany(new Document());
long count = deleteResult.getDeletedCount();
return count;
}
// 删除集合
public static void deleteCollection(MongoCollection<Document> collection) {
collection.drop();
}
/**
* <p>
* 关闭客户端
* </p>
*
* @author jiangyuechao 2018年4月9日 上午11:23:36
*/
public static void closeDb() {
mongoClient.close();
}
}
简单分析:
1. 使用 ip, port 连接mongodb数据库: static MongoClient mongoClient = new MongoClient(ip, 27017);
2. 连接数据库: database = mongoClient.getDatabase(databaseName);
3. 连接集合: MongoCollection<Document> collection = database.getCollection(collectionName);
4. 封装了基本的创建集合, insert ,delete操作.
使用实例
QuickTour例子:
package com.chaochao.mongodb;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Filters.gte;
import static com.mongodb.client.model.Filters.lt;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.bson.Document;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.Filters;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;
public class QuickTour {
static String databaseName = "firstDB";
static String collectionName = "firstCollection1";
static MongoCollection<Document> firstCollection;
public static void main(String[] args) {
QuickTour quickTour = new QuickTour();
quickTour.setUp();
// quickTour.updateMultipleDoc();
// quickTour.deleteMultiple();
quickTour.getAllDocuments();
}
/**
* 连接数据库
*/
public void setUp(){
MongoDBHelper.connect(databaseName);
firstCollection = MongoDBHelper.getCollection(collectionName);
}
public void getAllDocuments(){
MongoDBHelper.getAllDocuments(firstCollection);
}
public void getDocumentFirst(){
MongoDBHelper.connect(databaseName);
MongoCollection<Document> collection = MongoDBHelper.getCollection(collectionName);
String json = MongoDBHelper.getDocumentFirst(collection);
System.out.println(json);
}
/**
* 返回符合匹配条件的第一个doc
* @param collection
*/
public void getDocMatcheFilter(){
Document myDoc = firstCollection.find(eq("y", 2)).first();
System.out.println(myDoc.toJson());
}
public void getAllDocMatcheFilter(){
firstCollection.find(Filters.gt("i", 10)).forEach((Document document)->{System.out.println(document.toJson());});
}
public void updateOneDoc(){
UpdateResult updateResult = firstCollection.updateOne(Filters.eq("i", 12), new Document("$set", new Document("i", 21)));
System.out.println(updateResult.getModifiedCount());
}
public void updateMultipleDoc(){
UpdateResult updateResult = firstCollection.updateMany(lt("i", 100), new Document("$inc", new Document("i", 100)));
System.out.printf("count:%s,insertedId:%s",updateResult.getModifiedCount(),updateResult.getUpsertedId());
System.out.println();
}
public void deleteOne(){
DeleteResult deleteResult = firstCollection.deleteOne(eq("i", 121));
System.out.println(deleteResult.getDeletedCount());
}
public void deleteMultiple(){
DeleteResult deleteResult = firstCollection.deleteMany(gte("i", 100));
System.out.println(deleteResult.getDeletedCount());
}
/**
* 插入一个doc
* @param collection
*/
public void insertDocument(){
Document doc = new Document("name", "MongoDB")
.append("type", "database")
.append("count", 1)
.append("versions", Arrays.asList("v3.2", "v3.0", "v2.6"))
.append("info", new Document("x", 203).append("y", 102));
MongoDBHelper.insertDocument(firstCollection, doc);
}
/**
* 插入多个doc
* @param collection
*/
public void insertMultipleDoc(){
List<Document> documents = new ArrayList<Document>();
for (int i = 0; i < 100; i++) {
documents.add(new Document("i", i));
}
MongoDBHelper.insertManyDocument(firstCollection, documents);
}
public void countDocs(){
System.out.println(firstCollection.getNamespace().getCollectionName()+"-count:"+firstCollection.count());
}
}
这个例子展示了基本的增删改查操作,直接可以运行..安装mongodb参照官网,挺简单的,java 连接mongodb参照我前边的博客: Java驱动远程连接mongoDB(简明易懂版)
比如我的获取firstCollection1 集合的所有文档 :
{ "_id" : { "$oid" : "5a631d80070db90c43a3477d" }, "x" : 1.0 }
{ "_id" : { "$oid" : "5a631db0070db90c43a3477e" }, "y" : 2.0 }
{ "_id" : 10.0, "calc" : 2.555555000005E12 }
{ "_id" : { "$oid" : "5a66d717ba3c702c14df31b3" }, "name" : "MongoDB", "type" : "database", "count" : 1, "versions" : ["v3.2", "v3.0", "v2.6"], "info" : { "x" : 203, "y" : 102 } }
{ "_id" : { "$oid" : "5a9220cafffeed155066c035" }, "domainID" : { "$numberLong" : "2001" }, "type" : "chao" }
mongodb简单的CRUD还是很好理解的,这里只是一个入门,让你快速熟悉它的操作,跟传统的数据库逻辑还是一致的:
1. 连接数据库
2. 执行操作
3. 关闭连接
那些复杂的查询和更新操作,我们放在后边介绍,比如: 如何匹配数组中的元素? 如何匹配嵌入文档,查询值为 null 的字段 等等..
转载注明出处: http://www.cnblogs.com/jycboy/p/8758754.html
原文地址：https://www.cnblogs.com/jycboy/p/8758754.html
时间： 2024-10-16 10:57:21