Mybatis批量插入3种方式

@Mapper
public interface UserMapper {

    int insert(User user);

    int insertByBatch(List<User> users);

    int delete();
}

  <insert id="insert" parameterType="com.example.mybatisdemo.entity.User">
        insert into user (name,age) values(#{name},#{age})
    </insert>

    <insert id="insertByBatch" parameterType="java.util.List">
        insert into user (name,age) values
        <foreach collection="list" item="item" separator=",">
            (#{item.name},#{item.age})
        </foreach>
    </insert>

    <delete id="delete">
        delete from user
    </delete>

<foreach collection="list" item="item"  separator ="UNION ALL">
</foreach>

@SpringBootTest
class MybatisdemoApplicationTests {

    @Autowired
    UserMapper userMapper;

    @Autowired
    SqlSessionFactory sqlSessionFactory;

    private List<User> users = new ArrayList<User>();

    @Test
    void delete(){
        userMapper.delete();
    }

    @Test
    void insert() {
        for (int i = 0; i < 1000; i++){
            User user = new User();
            user.setName("人物"+i);
            user.setAge(i);
            users.add(user);
        }
        long start = System.currentTimeMillis();
        users.forEach(userMapper::insert);
        System.out.println(System.currentTimeMillis() - start);
    }

    @Test
    void insertByBatch(){
        for (int i = 0; i < 1000; i++){
            User user = new User();
            user.setName("人物"+i);
            user.setAge(i);
            users.add(user);
        }
        long start = System.currentTimeMillis();
        userMapper.insertByBatch(users);
        System.out.println(System.currentTimeMillis() - start);
    }

    @Test
    void insertByOnce(){
        SqlSession sqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH,false);
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        long start = 0L;
        try{
        for (int i = 0; i < 1000; i++){
            User user = new User();
            user.setName("人物"+i);
            user.setAge(i);
            start = System.currentTimeMillis();
            mapper.insert(user);
            if (i%1000 == 999){
                //每1000条提交一次防止内存溢出
                sqlSession.commit();
                sqlSession.clearCache();
            }
        }
        System.out.println(System.currentTimeMillis() - start);
        }catch (Exception e){
          //没有提交的数据进行回滚
          sqlSession.rollback();
      }finally{
         //关闭会话
         sqlSession.close();
      }
    }
}