I. Introduction
typeAliases is an alias processor class in MyBatis, translation is an alias meaning. Alias is the role of the Java processor type, give it a little simple alias, so we introduced the full class name in the XML file where you can use an alias instead. This can reduce a lot of workload, saving development time. For example let's use a full class name:
<select id="findByName" parameterType="string" resultType="com.aaa.entity.User">
select * from user where name like #{name}
</select>Second, the case
Modify mybatis-config.xml core profile
<typeAliases>
<!--typeAlias:某个java类型的全限定名；type:类名；alias:别名;如果类比较多，需要写很多个？怎么办？-->
<typeAlias type="com.aaa.entity.User" alias="user"></typeAlias>
</typeAliases>
The above case we can see in the following typeAliases label, can play an alias for the User class, if it has a lot of Java classes, it is not below there are a lot of <typeAlias> </ typeAlias>, if we can one kind other configurations to achieve a certain class for all the following packets are aliases, instead of one single class. The answer is yes.
MyBatis provides a package label for us to achieve the above functions can be configured by the label. Let us look at how to use the package label:
<typeAliases>
<!--package,默认别名是user-->
<package name="com.aaa.entity"></package>
</typeAliases>Configured as above can be achieved by batch aliases
Although we can use aliases bulk package, but there is a situation will lead to conflict, we have to simulate it, create a new User class, the User class below com.queen.mybatis.bean.child directory, which is a sub-bean package directory next, as shown:
This is an alias conflict. . . That we now have to how to solve this problem? In fact, you can think of, MyBatis are we thought of
A, using @Alias annotation to specify a new alias for a type
B, Modify User class file
IUserDao.xml modify configuration files
Through the above test we can conclude: the case of a batch of aliases, use @Alias annotation to specify a new alias for a type alias to avoid conflict error
