What is the usage of the TypeAliasRegistry in Mybatis?
TypeAliasRegistry is a class in the MyBatis framework that is used for managing the registration and retrieval of type aliases.
The main usage of TypeAliasRegistry is as follows:
- create an alternative name
TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
typeAliasRegistry.registerAlias("User", User.class);
By doing this, the User class is registered as an alias for User.
- find the true identity
TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
typeAliasRegistry.registerAlias("User", User.class);
Class<?> userType = typeAliasRegistry.resolveAlias("User");
This way, you can access the corresponding User class through the alias “User”.
- set a default alias
TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
typeAliasRegistry.registerDefaultAlias("int", Integer.class);
This way, the integer type int is registered as an alias for Integer.
The main purpose of TypeAliasRegistry is to facilitate developers in using type aliases in MyBatis configuration files, making the configuration cleaner and easier to read. In MyBatis configuration files, developers can directly use type aliases to specify parameter or return types without needing to write the full class names. For example:
<resultMap type="User" id="userResultMap">
<id property="id" column="user_id" />
<result property="username" column="user_name" />
</resultMap>
The type attribute directly uses the type alias User instead of writing the full class name com.example.User.
