euhat

Docker Memo

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不写dockerfile，快速运行镜像：
docker run -it --name redhat85 redhat/ubi8:8.5

Docker容器中ADD的文件是旧的：
docker-compose stop some-docker-id
docker-compose rm -v some-docker-id
docker-compose build --no-cache some-docker-id

Jni FindClass Returns Null

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One reason is the version of jvm.dll which contains JNI_CreateJavaVM is different from the version of the class file which is assigned to FindClass.

When FindClass returns null, we can check the reason like this:

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if (env->ExceptionCheck()) {
    env->ExceptionDescribe();
}

refer to: https://blog.csdn.net/liu_12345_liu/article/details/131154935

Print signature of a Java function:

javap -s -private Sample2

refer to: https://blog.csdn.net/fuhanghang/article/details/122257507

Vue3 自定义组件传参

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父组件

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<template>
  <HelloWor v-model:aaa="foo" />
  {{foo}}
</template>
<script setup>
import HelloWor from './Hello.vue'
import{ref}from 'vue'
const foo=ref()
</script>

子组件

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<template>
  <input v-model="yyy" />
</template>
<script setup>
import{useAttrs,computed}from 'vue'
const attrs = useAttrs()
const emit = defineEmits(['update:aaa'])//v-model父传子必须要用emit声明,否则父的v-model修饰符会不起作用。
const yyy=computed({
get() {return attrs.aaa},
set(newV) {emit('update:aaa',newV)}})
</script>

refer to:
https://segmentfault.com/a/1190000044885561

Visit Guest Service From Host With VirtualBox

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VBoxManage modifyvm "xubuntu" --natpf1 "guest-redis,tcp,,6379,,6379"
VBoxManage modifyvm "xubuntu" --natpf1 "guest-mysql,tcp,,3306,,3306"

Another method is to create two adapters, NAT + Host Only.

ps. Delete the forwarding rules like:
VBoxManage modifyvm "xubuntu" --natpf1 delete "guest-redis"

refer to:
https://blog.csdn.net/chinainvent/article/details/6234368
https://superuser.com/questions/1282666/host-cant-connect-to-guest-with-nat-networking-at-virtualbox-but-others
https://forums.virtualbox.org/viewtopic.php?t=32014

Arthas Memo

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dashboard
thread -b	# check dead lock
thread
thread 123
jad TestClass
redefine /root/TestClass.class
jmap -histo 1234 | head -20

refer to:
https://visualvm.github.io/index.html

SpringBoot Request And Response

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1, 简单参数
	定义方法形参，请求参数名与形参变量名一致。
	如果不一致，通过@RequestParam手动映射。
2，实体参数
	请求参数名，与实体对象的属性名一致，会自动接收封装。
3，数组集合参数
	数组：请求参数名与数组名一致，直接封装。
	集合：请求参数名与集合名一致，@RequestParam绑定关系。
4，日期参数
	@DateTimeFormat
5，JSON参数
	@RequestBody
6，路径参数
	@PathVariable
	@Autowired
	private HttpServletRequest request;

refer to:
https://www.bilibili.com/video/BV1kg4y1x7o6?p=70

Return Primary Key After Inserting In MyBatis

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@Mapper
public interface EmpMapper {
 
	@Delete("delete from emp where id = #{id}")
	public void delete(Integer id);
 
	@Options(useGeneratedKeys = true, keyProperty = "id")
	@Insert("insert into emp(username, name, gender, image, job, entrydate, dept_id, create_time, update_time)" +
			" values (#{username}, #{name}, #{gender}, #{image}, #{job}, #{entrydate}, #{deptId}, #{createTime}, #{updateTime})")
	public void insert(Emp emp);
 
	@Results({
		@Result(column = "dept_id", property = "deptId"),
		@Result(column = "create_time", property = "createTime"),
		@Result(column = "update_time", property = "updateTime")
	})
	@Select("select * from emp where id = #{id}")
	public Emp getById(Integer id);
 
	// or in application.properties
	// mybatis.configuration.map-underscore-to-camel-case=true
 
	//@Select("select * from emp where name like '%${name}%' and gender = #{gender} and " +
	//		"entrydate between #{begin} and #{end} order by update_time desc ")
	@Select("select * from emp where name like concat('%', #{name}, '%') and gender = #{gender} and " +
			"entrydate between #{begin} and #{end} order by update_time desc ")
	public List<Emp> list(String name, Short gender, LocalDate begin, LocalDate end);
}

refer to:
https://www.bilibili.com/video/BV1kg4y1x7o6/?p=124

IDEA Maven Speedup

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ideaIU-2023.2.1.win\plugins\maven\lib\maven3\conf\settings.xml

  <mirrors>
...
	<mirror>
		<id>aliyunmaven</id>
		<mirrorOf>*</mirrorOf>
		<name>阿里云公共仓库</name>
		<url>https://maven.aliyun.com/repository/public</url>
	</mirror>
...
  </mirrors>
...
  <profiles>
...
	<profile>
	<id>jdk-1.8</id>
	<activation>
		<activeByDefault>true</activeByDefault>
		<jdk>1.8</jdk>
	</activation>
	<properties>
		<maven.compiler.source>1.8</maven.compiler.source>
		<maven.compiler.target>1.8</maven.compiler.target>
		<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
	</properties>
	</profile>
  </profiles>

refer to:
https://blog.csdn.net/baikunlong/article/details/113762152
https://www.bilibili.com/video/BV1kg4y1x7o6?p=49
https://mvnrepository.com