Spring Mongodb入门

安装Spring for Mongodb

Spring项目为方便对Mongodb的操作,建立了spring-data的子项目,地址在:

http://www.springsource.org/spring-data/mongodb,目前版本是1.0.0M2阶段,已支持对Mongodb的一系列基本操作。我们先从http://www.springsource.org/spring-data/mongodb中下载相关的包:spring-data-document-1.0.0.M2.zip,下载解压后,将解压后的四个JAR文件放到工程路径的lib库中,本文中还将使用Spring 3.0.4的版本,请读者自行下载配置。

Spring Mongodb的配置

目前,可以有两种方式对Spring mongodb进行配置。第一种是使用Spring 3中的注解,另外一种是使用传统的XML配置。下面分别进行讲解:

使用Spring 3中的注解

首先在配置类中,要继承AbstractMongoConfiguration类,代码如下:

package com.mkyong.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.document.mongodb.MongoTemplate;
import org.springframework.data.document.mongodb.config.AbstractMongoConfiguration;
import com.mongodb.Mongo;
/**
* Spring MongoDB configuration file
*
*/
@Configuration
public class SpringMongoConfig extends AbstractMongoConfiguration {
    @Override
    
public @Bean Mongo mongo() throws Exception {
        
return new Mongo( " localhost " );
    }
    @Override
    
public @Bean MongoTemplate mongoTemplate() throws Exception {
        
return new MongoTemplate(mongo(), " yourdb " , " yourCollection " );
    }
}

这里,引入了MongoTemplate模版类,并且使用对连接数据库的地址,数据库名和collection进行了初始化。

在调用Spring Mongodb配置时,只需要在需要使用的类中调用AnnotationConfigApplicationContext,传入刚才配置好的SpringMongoConfig类即可。如下代码所示:

  ApplicationContext
ctx
= new AnnotationConfigApplicationContext(SpringMongoConfig. class );
MongoOperations
mongoOperation
= (MongoOperations)ctx.getBean( " mongoTemplate " );

当获得了mongoOperation对象的实例后,即可进行对mongodb的相关操作。

使用XML配置文件

使用XML配置文件的方法如下:

<? xml version="1.0" encoding="UTF-8" ?>
< beans xmlns ="http://www.springframework.org/schema/beans"
    xmlns:xsi
="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context
="http://www.springframework.org/schema/context"
    xmlns:mongo
="http://www.springframework.org/schema/data/mongo"
    xsi:schemaLocation
="http://www.springframework.org/schema/context
          http://www.springframework.org/schema/context/spring-context-3.0.xsd
          http://www.springframework.org/schema/data/mongo
          http://www.springframework.org/schema/data/mongo/spring-mongo-1.0.xsd
          http://www.springframework.org/schema/beans
          http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"
>
    
<!-- Default bean name is 'mongo' -->
    
< mongo:mongo host ="localhost" port ="27017" />
    
< bean id ="mongoTemplate"
                 class
="org.springframework.data.document.mongodb.MongoTemplate" >
        
< constructor-arg ref ="mongo" />
        
< constructor-arg name ="databaseName" value ="yourdb" />
        
< constructor-arg name ="defaultCollectionName" value ="yourCollection" />
    
</ bean >
    
<!-- To translate any MongoExceptions thrown in @Repository annotated classes -->
    
< context:annotation-config />
</ beans >

 

注意这里引用相关的命名空间xmlns:mongo="http://www.springframework.org/schema/data/mongo"
,并且在名为mongoTemplate中注入相关的数据库地址,数据库名即可,使用方法如下:

ApplicationContext ctx = new GenericXmlApplicationContext( " mongo-config.xml " );

使用Spring Mongodb实现增删改查操作

下面通过实例讲解如何使用Spring Mongodb实现增删改查操作,假设我们现在有一个实

体类user如下:

package com.mkyong.user;
public class User {
private String id;
private String firstname;
private String lastname;
private int age;
// getter and setter methods
}

接下来,我们看具体的操作代码,如下,这里假设要将user类保存到名为userprofile的数据集中。

package com.mkyong.core;

import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.GenericXmlApplicationContext;
import org.springframework.data.document.mongodb.MongoOperations;
import org.springframework.data.document.mongodb.query.Criteria;
import org.springframework.data.document.mongodb.query.Query;
import org.springframework.data.document.mongodb.query.Update;
import com.mkyong.config.SpringMongoConfig;
import com.mkyong.user.User;
public class App
{
public static void main( String[] args )
{
ApplicationContext ctx
= new AnnotationConfigApplicationContext(SpringMongoConfig. class );
MongoOperations mongoOperation
= (MongoOperations)ctx.getBean( " mongoTemplate " );
User user
= new User( " 1001 " , " yong " , " mook kim " , 30 );
// 保存
mongoOperation.save( " userprofile " ,user);
// 查找
User savedUser = mongoOperation.findOne( " userprofile " ,
new Query(Criteria.where( " id " ).is( " 1001 " )),
User.
class );
System.out.println(
" savedUser : " + savedUser);
// 更新
mongoOperation.updateFirst( " userprofile " ,
new Query(Criteria.where( " firstname " ).is( " yong " )),
Update.update(
" lastname " , " new lastname " ));
User updatedUser
= mongoOperation.findOne( " userprofile " ,
new Query(Criteria.where( " id " ).is( " 1001 " )),
User.
class );
System.out.println(
" updatedUser : " + updatedUser);
// 删除
mongoOperation.remove( " userprofile " ,
new Query(Criteria.where( " id " ).is( " 1001 " )),
User.
class );
// 显示当前列表
List < User > listUser =
mongoOperation.getCollection(
" userprofile " , User. class );
System.out.println(
" Number of user = " + listUser.size());
}
}

 

输出结果如下:

savedUser : User [id = 1001 , firstname = yong, lastname = mook kim, age = 30 ]
updatedUser : User [id
= 1001 , firstname = yong, lastname = new lastname, age = 30 ]
Number of user
=

Spring mongodb插入数据

下面详细讲解如何使用spring mongodb插入数据。在spring mongodb中,插入数据到

mongodb有如下几种方法:

User user = new User( " ... " );
// 将user对象保存到"user"这个collection中
mongoOperation.save(user);
// 将user对象保存到"new collection"这个collection中
mongoOperation.save( " new collection " ,user);
// 将user对象保存到"user"这个collection中
mongoOperation.insert(user);
// 将user对象保存到"new collection"这个collection中
mongoOperation.insert(
" new collection " , user);
// 将user的对象列表(List)保存到"user"collection中去
mongoOperation.insertList(userInList);
// 将user的对象列表(List)保存到"new collection"collection中去
mongoOperation.insertList( " new collection " , userInList);

要注意的是,Spring mongodb中,当没有指定collection时,就会把对象保存到以对象命名的collection中。比如上例中的mongoOperation.insert(user),由于没指定collection的名称,所以会把user对象保存到user这个新建立的collection中。

另外请注意其中的save和insert的区别。它们的区别为:

1)save意思是,当记录不存在时插入,或者是当记录已存在是更新,实际上就是saveorupdate的意思。

2) insert的意思是:当记录不存在时插入,而如果记录存在时则忽略,继续插入。

下面举例子说明:

package com.mkyong.core;
import java.util.ArrayList;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.data.document.mongodb.MongoOperations;
import org.springframework.data.document.mongodb.query.Criteria;
import org.springframework.data.document.mongodb.query.Query;
import com.mkyong.config.SpringMongoConfig;
import com.mkyong.user.User;
public class App {
public static void main(String[] args) {
ApplicationContext ctx
= new AnnotationConfigApplicationContext(
SpringMongoConfig.
class );
MongoOperations mongoOperation
= (MongoOperations) ctx
.getBean(
" mongoTemplate " );
// 新增一个user对象,并把它放到"ABC"这个collection中
System.out.println( " Case 1... " );
User userA
= new User( " 1111 " , " user " , " A " , 99 );
mongoOperation.save(
" ABC " , userA);
// 查找刚插入的user对象
User userA1 = mongoOperation.findOne( " ABC " ,
new Query(Criteria.where( " id " ).is( " 1111 " )), User. class );
System.out.println(userA1);
// 插入新的user,放到userB这个collection中去
System.out.println( " Case 2... " );
User userB
= new User( " 2222 " , " user " , " B " , 99 );
mongoOperation.save(userB);
// 查找
User userB1 = mongoOperation.findOne(
new Query(Criteria.where( " id " ).is( " 2222 " )), User. class );
System.out.println(userB1);
// 插入对象列表,放到arraylist中
System.out.println( " Case 3... " );
User userC
= new User( " 3333 " , " user " , " C " , 99 );
User userD
= new User( " 4444 " , " user " , " D " , 99 );
User userE
= new User( " 5555 " , " user " , " E " , 99 );
List
< User > userList = new ArrayList < User > ();
userList.add(userC);
userList.add(userD);
userList.add(userE);
mongoOperation.insertList(
" ABC-List " , userList);
List
< User > users = mongoOperation.find( " ABC-List " , new Query(Criteria
.where(
" firstname " ).is( " user " )), User. class );
for (User temp : users) {
System.out.println(temp);
}
}
}

 

输出结果如下:

Case 1 ...
User [id
= 1111 , firstname = user, lastname = A, age = 99 ]
Case
2 ...
User [id
= 2222 , firstname = user, lastname = B, age = 99 ]
Case
3 ...
User [id
= 3333 , firstname = user, lastname = C, age = 99 ]
User [id
= 4444 , firstname = user, lastname = D, age = 99 ]
User [id
= 5555 , firstname = user, lastname = E, age = 99 ]

更新Document

在mongodb中,可以使用save,updateFirst(),updateMulti()方法来进行更新,下面

是相关的例子

public class App {
public static void main(String[] args) {
ApplicationContext ctx
= new AnnotationConfigApplicationContext(
SpringMongoConfig.
class );
MongoOperations mongoOperation
= (MongoOperations) ctx
.getBean(
" mongoTemplate " );
User user
= new User( " 1000 " , " user-first " , " user-last " , 17 );
System.out.println(
" Case 1...by save() " );
mongoOperation.save(user);
User userPrint1
= mongoOperation.findOne( new Query(Criteria.where( " id " ).is( " 1000 " )), User. class );
System.out.println(userPrint1);
// 修改user对象的lastname
user.setLastname( " new last name " );
// 更新user对象
mongoOperation.save(user);
User userPrint2
= mongoOperation.findOne( new Query(Criteria.where( " id " )
.is(
" 1000 " )), User. class );
System.out.println(userPrint2);
// Case 2 ... update firstname field, $set
System.out.println( " Case 2...by updateFirst() - $set " );
// 将id为1000的user对象的firstname属性的值更新为”new firstname”
mongoOperation.updateFirst( " user " ,
new Query(Criteria.where( " _id " ).is( " 1000 " )),
Update.update(
" firstname " , " new first name " ));
User userPrint3
= mongoOperation.findOne( new Query(Criteria.where( " id " )
.is(
" 1000 " )), User. class );
System.out.println(userPrint3);
// 对id为1000的user的age加上10
System.out.println( " Case 3...by updateFirst() - $inc " );
Update updateAge
= new Update();
updateAge.inc(
" age " , 10 );
mongoOperation.updateFirst(
" user " ,
new Query(Criteria.where( " _id " ).is( " 1000 " )), updateAge);
User userPrint4
= mongoOperation.findOne( new Query(Criteria
.where(
" _id " ).is( " 1000 " )), User. class );
System.out.println(userPrint4);
}
}

结果为:

Case 1 ...by save()
User [id
= 1000 , firstname = user - first, lastname = user - last, age = 17 ]
User [id
= 1000 , firstname = user - first, lastname = new last name, age = 17 ]
Case
2 ...by updateFirst() - $set
User [id
= 1000 , firstname = new first name, lastname = new last name, age = 17 ]
Case
3 ...by updateFirst() - $inc
User [id
= 1000 , firstname = new first name, lastname = new last name, age = 27 ]

 

此外,还支持使用updateMulti,updateMulti是将所有的对象进行更新,比如:

mongoOperation.updateMulti( " user " ,
new Query(Criteria.where( " firstname " ).is( " yong " )),
Update.update(
" age " , 40 ));

表示将所有firstname为yong的user对象的age属性全部更新为40。

查询Document

在spring mongodb中,可以使用findOne(),find()和getCollection()去查询mongodb,常见的用法如下:

User user = new User( " ... " );
// 找到第一个id=1001的user对象
User user = mongoOperation.findOne( " test " , new Query(Criteria
.where(
" id " ).is( " 1001 " )), User. class );
// 从test集合中获得所有id<=1000并且age=21的user对象
List < User > users = mongoOperation.find( " test " , new Query(Criteria
.where(
" id " ).lte( " 2001 " ).and( " age " ).is( 21 )), User. class );
// 从test 集合中获得所有的user对象列表
List < User > users = mongoOperation.getCollection( " test " , User. class );

删除document

在spring mongodb中, 删除document使用remove方法,示例如下:

在spring mongodb中, 删除document使用remove方法,示例如下:
User user
= new User( " ... " );
// 删除user集合中的user对象
mongoOperation.remove(user);
// 删除test集合下的id=2的user对象
mongoOperation.remove( " test " , new Query(Criteria
.where(
" id " ).is( " 2 " )));
// 删除test集合下的,id=3的user对象,最后并且返回这个被删除的对象
User deletedUser = mongoOperation.findAndRemove( " test " ,
new Query(Criteria.where( " id " ).is( " 3 " )), User. class );

 


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