<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>

package com.offcn.springbootdemo1;

import com.offcn.springbootdemo1.mapper.UUserMapper;
import com.offcn.springbootdemo1.pojo.UUser;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;
import java.util.List;

//添加整合junit注解
@RunWith(SpringRunner.class)
@SpringBootTest(classes = Springbootdemo1Application.class)
public class AppTest {
　　 //注入Mapper对象，用来获取List<UUser>集合
    @Resource
    private UUserMapper userMapper;
    @Test
    public void TestMethod(){
        List<UUser> uUsers = userMapper.selectUUser();
        for (UUser uUser : uUsers) {
            System.out.println(uUser);
        }
    }
}