spring mongodb中去掉_class列

調用mongoTemplate的save方法時, spring-data-mongodb的TypeConverter會自動給document添加一個_class屬性, 值是你保存的類名. 這種設計並沒有什么壞處. spring-data-mongodb是為了在把document轉換成Java對象時能夠轉換到具體的子類. 但有時候我們並不希望出現這個字段, 主要是看上去會比較"煩". 可以通過設置MappingMongoConverter的MongoTypeMapper來解決這個問題.

 

DefaultMongoTypeMapper類的構造函數的第一個參數是Type在MongoDB中名字. 設置為null的話就不會在保存時自動添加_class屬性.所以需要覆寫 

 

spring的配置文件方式:

 

<mongo:mongo host="localhost" port="27017" />    
<mongo:db-factory dbname="database" />    
     
 <bean id="mappingContext"    
    class="org.springframework.data.mongodb.core.mapping.MongoMappingContext" />    
     
 <bean id="defaultMongoTypeMapper"    
    class="org.springframework.data.mongodb.core.convert.DefaultMongoTypeMapper">    
    <constructor-arg name="typeKey"><null/></constructor-arg>    
 </bean>    
     
 <bean id="mappingMongoConverter"    
    class="org.springframework.data.mongodb.core.convert.MappingMongoConverter">    
    <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" />    
    <constructor-arg name="mappingContext" ref="mappingContext" />    
    <property name="typeMapper" ref="defaultMongoTypeMapper" />    
 </bean>    
     
 <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate">    
    <constructor-arg name="mongoDbFactory" ref="mongoDbFactory" />    
    <constructor-arg name="mongoConverter" ref="mappingMongoConverter" />    
 </bean> 

   

注解方式：

 

@EnableMongoRepositories(  
        basePackages = {"com.dhp"},  
        repositoryFactoryBeanClass = DHBMongoRepositoryFactoryBean.class  
)  
@PropertySource("classpath:mongo.properties")  
@EnableMongoAuditing  
public class MongoConfig extends AbstractMongoConfiguration {  
  
    @Value("${mongo.connectionString}")  
    private String connectionString;  
    @Value("${mongo.dbName}")  
    private String dbName;  
  
    @Autowired  
    private ApplicationContext appContext;  
  
    @Override  
    protected String getDatabaseName() {  
        return dbName;  
    }  
  
    @Override  
    @Bean  
    public Mongo mongo() throws Exception {  
        MongoClientURI mongoClientURI = new MongoClientURI(connectionString);  
        return new MongoClient(mongoClientURI);  
    }  
  
    @Override  
    @Bean  
    public MongoTemplate mongoTemplate() throws Exception {  
        MongoDbFactory factory = mongoDbFactory();  
  
        MongoMappingContext mongoMappingContext = new MongoMappingContext();  
        mongoMappingContext.setApplicationContext(appContext);  
  
        MappingMongoConverter converter = new MappingMongoConverter(new DefaultDbRefResolver(factory), mongoMappingContext);  
        converter.setTypeMapper(new DefaultMongoTypeMapper(null));  
  
        return new MongoTemplate(factory, converter);  
    }  
  
  
    @Bean  
    public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() {  
        return new PropertySourcesPlaceholderConfigurer();  
    }  
}  

　　

當使用Servlet 3初始化確保添加應用程序上下文到mongo中，如果不加上這兩句，會報異常：org.springframework.expression.spel.SpelEvaluationException
@Autowired
private ApplicationContext appContext;
mongoMappingContext.setApplicationContext(appContext);