Mybatis的注解@ResultType的场景是什么？-灵析社区
momo`@ResultType` 注解是搭配 `ResultHandler` 来用的。 > REF: [https://mybatis.org/mybatis-3/java-api.html#mapper-> annotations](https://link.segmentfault.com/?enc=6L2as3ciyY7OiMOygNlqpQ%3D%3D.a5XBDyN66%2FH8dPNVUw1pJEoL3LuFqlKZiqgL31ecgchUkk21tcgo8FHmGmnfU%2F4iWYvO87J8P%2FLW3hrSUOx2ow%3D%3D) > > This annotation is used when using a **result handler**. In that case, the > return type is `void` so MyBatis must have a way to determine the type of > object to construct for each row. If there is an XML result map, use the > `@ResultMap` annotation. If the result type is specified in XML on the > `` element, then no other annotation is necessary. In other cases, > use this annotation. For example, if a `@Select` annotated method will use a > result handler, the return type must be `void` and this annotation (or > `@ResultMap`) is required. This annotation is ignored unless the method > return type is `void`. 所以你那个写法不对，起码你得定义一个 ResultHandler 出来： @Select("select * from Student") @ResultType(Student.class) void queryStudent(StudentResultHandler resultHandler); public class StudentResultHandler implements ResultHandler { private final List students; public StudentResultHandler() { students = new ArrayList(); } @Override public void handleResult(ResultContext context) { Student student = (Student)context.getResultObject(); students.add(student); } }