sping data

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 classSpringMongoConfig extendsAbstractMongoConfiguration {
    @Override
     public @Bean Mongo mongo() throws Exception {
         return new Mongo( " localhost " );
    }
    @Override
     public @Bean MongoTemplate mongoTemplate() throwsException {
         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 = newAnnotationConfigApplicationContext(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:mongohost ="localhost"port ="27017"/>
     < beanid ="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 classUser {
private String id;
private String firstname;
private String lastname;
private intage;
// 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 classApp
{
public staticvoid 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 classApp {
public staticvoid 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 " , newQuery(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 classApp {
public staticvoid 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 " , newQuery(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 );