mongo中插入的数据去掉_class
在spring for mongodb中，会发现当一个pojo序列化为一个document时，会出现如下
情况：
public class User {
String username;
String password;
}
转变为mongodb 时
Java代码
-
MongoOperations mongoOperation = (MongoOperations)ctx.getBean(
“mongoTemplate”
);
-
User user =
new
User(
“abc”
,
“password123”
);
-
mongoOperation.save(user,
“users”
);
会发现document中，多了个_class属性：
Java代码
-
{
-
“_class”
:
“com.abc.user.User”
,
-
-
……………….
-
}
多了_class的意义，在下面这个链接有很好的解答：
http://stackoverflow.com/questions/6810488/spring-data-mongodb-mappingmongoconverter-remove-class/
，其实就是说，为了在把document转换成Java对象时能够转换到具体的子类.
要去掉的方法简单：DefaultMongoTypeMapper类的构造函数的第一个参数是Type在MongoDB中名字. 设置为null的话就不会在保存时自动添加_class属性.所以需要覆写
MappingMongoConverter。
1）用注解的方法取消：
Java代码
-
@Configuration
-
public
class
SpringMongoConfig{
-
-
public
@Bean
-
MongoDbFactory mongoDbFactory()
throws
Exception {
-
return
new
SimpleMongoDbFactory(
new
Mongo(),
“database”
);
-
}
-
-
public
@Bean
-
MongoTemplate mongoTemplate()
throws
Exception {
-
-
-
MappingMongoConverter converter =
-
new
MappingMongoConverter(mongoDbFactory(),
new
MongoMappingContext());
-
converter.setTypeMapper(
new
DefaultMongoTypeMapper(
null
));
-
-
MongoTemplate mongoTemplate =
new
MongoTemplate(mongoDbFactory(), converter);
-
-
return
mongoTemplate;
-
-
}
-
-
2
）XML配置文件
-
<pre name=
“code”
class
=
“java”
><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>
-
-
</pre>
-
<br>
-
<br>
-
<br>
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