Plain Simple MongoDB Spring Integration

You know what is MongoDB and what is Spring Framework and want to use the first inside the second? Here's short plain and simple integration between the two:

• Properties file with server and database details (resides in classpath in this example):

db.host=localhostdb.port=27017app.db.name=app

• If you don't use Java-based container configuration (you should start using it!):

1. application-config.xml (or whatever you call it):
   

   <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"       xsi:schemaLocation="http://www.springframework.org/schema/beans           http://www.springframework.org/schema/beans/spring-beans-3.0.xsd           http://www.springframework.org/schema/context           http://www.springframework.org/schema/context/spring-context-3.0.xsd">    <context:property-placeholder                 location="classpath:db.properties"/>    <bean id="mongo" class="com.mongodb.Mongo">       <constructor-arg value="${db.host}"/>       <constructor-arg value="${db.port}"/>   </bean>   <bean id="db"       class="com.mongodb.spring.config.DbFactoryBean">       <property name="mongo" ref="mongo"/>       <property name="name" value="${app.db.name}"/>   </bean></beans>

2. The com.mongodb.spring.config.DbFactoryBean class:
   

    public class DbFactoryBean implements FactoryBean<DB> {            private Mongo mongo;        private String name;            @Override        public DB getObject() throws Exception {            Assert.notNull(mongo);            Assert.notNull(name);            return mongo.getDB(name);        }          @Override       public Class<?> getObjectType() {           return DB.class;       }          @Override       public boolean isSingleton() {           return true;       }          @Required       public void setMongo(Mongo mongo) {           this.mongo = mongo;       }       @Required          public void setName(String name) {           this.name = name;       } }

• If you do use Java-based container configuration - here's your @Configuration class:

    @Configuration    public class ApplicationConfiguration {            @Value("${app.db.name}")        private String appDbName;            @Value("${db.host}")        private String dbHost;           @Value("${db.port}")       private int dbPort;             @Bean       public DB db() throws UnknownHostException {           return mongo().getDB(appDbName);       }          @Bean       public Mongo mongo() throws UnknownHostException {           return new Mongo(dbHost, dbPort);       }   }

That's, actually, it - enjoy. If you feel some part of the puzzle is missing, please leave a comment.

This post was originally posted in my blog - http://jbaruch.wordpress.com