Author: Robin

nodejs

gitbook

Post author By Robin
Post date August 20, 2021
No Comments on gitbook

npm gitbook 文档编辑生成器

first step : npm install -g gitbook-cli

second step : gitbook init

third step: gitbook serve (and your application is running on port 4000)

Tags gitbook

uml

uml class diagram

可用的元素声明

abstract abstract

abstract class “abstract class”

annotation annotation

circle circle

class class

diamond diamond

entity entity

enum enum

interface interface

类实体关系

Type Symbol

Extension（扩展） <|–

Composition（组合） *–

Aggregation（聚合） o–

也可以使用 extends implement

定义属性与方法

Object : equals()
ArrayList : Object[] elementData
ArrayList : size()

通过类对象：方法 / 属性定义

也可以

class

{

嵌套在类

Object[] elementData
int size()

返回属性后置

flightNumber : Integer
departureTime : Date

强制声明为field 或 method 否则根据是否有括号判断

{field} A field
{method} Some method

}

可访问性

Character Icon for field Icon for method Visibility

-private

#protected

~ package private

+public

抽象与静态

@startuml
class Dummy {
{static} String id
{abstract} void methods()
}
@enduml

Tags classdiagram

uml

plantuml

Post author By Robin
Post date August 2, 2021
No Comments on plantuml

plantuml 是uml 的其中一种标准和实现形式

其代码逻辑实现由java 通过正则表达式逐行逐行解析uml文本

然后生成uml的数据结构实体的结构关联结构等。

具体命令行用法

java -jar pantuml.jar XXX.puml -o XXX.png

可以把XXX.puml 转化为 png的可视化关联对象图片

以@startuml @enduml 包裹 uml代码

@startuml

开始uml

@enduml

结束uml

！inlcude $umlfile

包含/嵌套其他uml文件

title $title

定义 uml title

title

end title

定义多行title

定义实体后 as 可以起别名

Tags plantuml

php

php artisan tinker

今天，我们将通过介绍 Laravel 中一个不太为人所知的功能，来展示如何快捷的调试数据库中的数据。通过使用 Laravel artisan 内建的 php artisan tinker, 我们可以很方便的看到数据库中的数据并且执行各种想要的操作。

Laravel artisan 的 tinker 是一个 REPL (read-eval-print-loop)，REPL 是指交互式命令行界面，它可以让你输入一段代码去执行，并把执行结果直接打印到命令行界面里。

// see the count of all users
App\User::count();

// find a specific user and see their attributes
App\User::where('username', 'samuel')->first();

// find the relationships of a user
$user = App\User::with('posts')->first();
$user->posts;

factory(App\User::class, 10)->create();
App\User::all();
App\User::count();

$user = new App\User;
$user->name = "Wruce Bayne";
$user->email = "iambatman@savegotham.com";
$user->save();

doc XXX

查阅某个方法的文档

show XXX

显示某个方法的代码

Tags laravel, tinker

php

laravel Form magic 方法

laravel 的form 对象有magic方法可以快速添加表单项

/**
 * Class Form.
 *
 * @method Field\Text           text($name, $label = '')
 * @method Field\Password       password($name, $label = '')
 * @method Field\Checkbox       checkbox($name, $label = '')
 * @method Field\CheckboxButton checkboxButton($name, $label = '')
 * @method Field\CheckboxCard   checkboxCard($name, $label = '')
 * @method Field\Radio          radio($name, $label = '')
 * @method Field\RadioButton    radioButton($name, $label = '')
 * @method Field\RadioCard      radioCard($name, $label = '')
 * @method Field\Select         select($name, $label = '')
 * @method Field\MultipleSelect multipleSelect($name, $label = '')
 * @method Field\Textarea       textarea($name, $label = '')
 * @method Field\Hidden         hidden($name, $label = '')
 * @method Field\Id             id($name, $label = '')
 * @method Field\Ip             ip($name, $label = '')
 * @method Field\Url            url($name, $label = '')
 * @method Field\Color          color($name, $label = '')
 * @method Field\Email          email($name, $label = '')
 * @method Field\Mobile         mobile($name, $label = '')
 * @method Field\Slider         slider($name, $label = '')
 * @method Field\File           file($name, $label = '')
 * @method Field\Image          image($name, $label = '')
 * @method Field\Date           date($name, $label = '')
 * @method Field\Datetime       datetime($name, $label = '')
 * @method Field\Time           time($name, $label = '')
 * @method Field\Year           year($column, $label = '')
 * @method Field\Month          month($column, $label = '')
 * @method Field\DateRange      dateRange($start, $end, $label = '')
 * @method Field\DateTimeRange  dateTimeRange($start, $end, $label = '')
 * @method Field\TimeRange      timeRange($start, $end, $label = '')
 * @method Field\Number         number($name, $label = '')
 * @method Field\Currency       currency($name, $label = '')
 * @method Field\SwitchField    switch($name, $label = '')
 * @method Field\Display        display($name, $label = '')
 * @method Field\Rate           rate($name, $label = '')
 * @method Field\Divider        divider($title = '')
 * @method Field\Decimal        decimal($column, $label = '')
 * @method Field\Html           html($html)
 * @method Field\Tags           tags($column, $label = '')
 * @method Field\Icon           icon($column, $label = '')
 * @method Field\Captcha        captcha($column, $label = '')
 * @method Field\Listbox        listbox($column, $label = '')
 * @method Field\Table          table($column, $label, $builder)
 * @method Field\Timezone       timezone($column, $label = '')
 * @method Field\KeyValue       keyValue($column, $label = '')
 * @method Field\ListField      list($column, $label = '')
 * @method mixed                handle(Request $request)
 */

真实调用的方法

 /**
     * Generate a Field object and add to form builder if Field exists.
     *
     * @param string $method
     * @param array  $arguments
     *
     * @return Field|$this
     */
    public function __call($method, $arguments)
    {
        if (!$this->hasField($method)) {
            return $this;
        }

        $class = BaseForm::$availableFields[$method];

        $field = new $class(Arr::get($arguments, 0), array_slice($arguments, 1));

        return tap($field, function ($field) {
            $this->pushField($field);
        });
    }

Tags laravel, laravel-admin

php

php __call

Post author By Robin
Post date July 4, 2021
No Comments on php __call

__call 属于php 类对象的magic 方法

当调用一个不存在与类定义的方法就会在call中调用

 function __call($name,$arguments) {  

 }

$name 为方法名字

$argument 为方法参数

Tags __call

java

DiscoverClient ribbon Feign 服务发现与调用

Post author By Robin
Post date June 18, 2021
No Comments on DiscoverClient ribbon Feign 服务发现与调用

服务发现是服务治理的一个很重要的点

所有注册在服务平台的微服务必须要能被发现然后调用

而我们调用其他服务一般有三种方法

DiscoverClient ribbon Feign

DiscoverClient 是更加低层的方法当DiscoverClient 需要寻找服务时其实是向服务注册器（例如 eureka）发送 http 请求获取躯体服务信息包括 ip port 等

@SpringBootApplication
@EnableDiscoveryClient
class Application {

    @Autowired
    DiscoveryClient discoveryClient
}

添加了注解@EnableDiscoveryClient

然后就能自动注入 discoverClient

 @Autowired
 DiscoveryClient discoveryClient


 def restTemplate = new RestTemplate()
 def serverList = discoveryClient.getInstances("ROBIN-ADMIN")
 println(serverList)
        restTemplate.getForObject("${serverList[0].getUri()}/api/ribbon",Map.class)

获取到discoverClient 就能通过服务名字查找服务实例并且通过RestTemplate 调用服务接口了

Ribbon是调用了 discoverClient 调用服务的但是他提供了负载均衡功能，不显式调用某个服务实例而是通过策略调用某类服务的其中一个达到负载均衡效果


@SpringBootApplication
class RibbonApplication {

    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate()
    }
}

在注册RestTemplate对象时添加LoadBalanced 注解

LoadBalanced 会自动实例化restTemplate 的服务均衡策略具体查看LoadBalance接口会定时ping各个服务实例也会用譬如回环轮询策略寻找服务实例

当restTemplate 调用服务时通过策略调用服务实例

restTemplate.getForObject("http://ROBIN-ADMIN/api/health",Map.class)

ROBIN-ADMIN 为某类服务的服务ID

Feign 是更加接近业务的服务调用方式

maven 添加依赖

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

添加Feign注解

@EnableFeignClients
class RibbonApplication {

}

新建接口对象

package org.robin.ribbon.feign

import org.springframework.cloud.openfeign.FeignClient
import org.springframework.web.bind.annotation.RequestMapping

@FeignClient("ROBIN-ADMIN")
interface RobinAdminService {

    @RequestMapping("/api/ribbon")
    Map ribbon()


    @RequestMapping("/api/health")
    Map health()

}

spring会自动生成 RobinAdminService

调用该对象的方法可以调用对应微服务的接口

Tags discoverClient, feign, ribbon

php

DB Facade

Post author By Robin
Post date June 12, 2021
No Comments on DB Facade

使用laravel 的数据库Facade 可以比较好的执行数据库sql

$array = DB::select("select * from admin_users");
//raw 执行sql      

$object = DB::table("admin_users")->where("id","=","1")->first();
//获取查询第一条

$array = DB::table("admin_users")->where("id","=","1")->get();
//
get获取数据列表
       
$array = DB::table("admin_users")->where("id","=","1")->skip(0)->take(1)->get();
//分页查询

$array = DB::table("admin_users")->where("id","=","1")->skip(0)->limit(1)->get();
//分页查询

DB::transaction(function (){
           //内部执行开启事务
});

//手动控制事务
DB::beginTransaction();
DB::commit();
DB::rollBack();

Tags DB Facade, laravel

java

eureka

Post author By Robin
Post date June 1, 2021
No Comments on eureka

作为微服务服务注册供应方

默认在本机 http://localhost:8761/eureka/提供服务

注册请求地址在 apps/{service-name} POST 发送本机服务信息

注销请求地址在 apps/{service-name}/{id} DELETE 发送请求

心跳请求地址在 apps/{service-name}/{id} PUT 发送请求

状态请求地址在 apps/{service-name}/{id}/status PUT 发送请求

删除状态请求地址在 apps/{service-name}/{id}/status DELETE 发送请求

Tags eureka

php

php reactive socket

php socket 第三方库 composer require react/socket

该库针对 socket / 流做事件监听（应该是epoll ）主线程做事件循环（reactive）所以该reactive 框架貌似只能在 linux下使用

server

<?php

require '../vendor/autoload.php';

echo "enter script\n";

$loop = React\EventLoop\Factory::create();
$socket = new React\Socket\Server('127.0.0.1:8080', $loop);

$socket->on('connection', function (React\Socket\ConnectionInterface $connection) {
    echo "" . $connection->getRemoteAddress() . "client connected\n";
    $connection->write("Hello " . $connection->getRemoteAddress() . "!\n");
    $connection->write("Welcome to this amazing server!\n");
    $connection->write("Here's a tip: don't say anything.\n");

    $connection->on('data', function ($data) use ($connection) {
        echo "" . $data . "\n";
        //$connection->close();
    });
});

echo "server started at 8080\n";

$loop->run();

其中$loop 就是事件循环对象

client

<?php

require '../vendor/autoload.php';


$loop = React\EventLoop\Factory::create();
$connector = new React\Socket\Connector($loop);

$connector->connect('127.0.0.1:8080')->then(function (React\Socket\ConnectionInterface $connection) use ($loop) {
    echo "client connected\n";
    $connection->write("Hello World!\n");
    $connection->on('data', function ($data) use ($loop, $connection) {
        echo "" . $data . "\n";
        //$connection->close();
        //$output = new React\Stream\WritableResourceStream(fopen("./client.txt", "w"),$loop);
        //$output = fopen("./client.txt", "w");
        //fwrite($output,$data);
        //$output->write("" . $data . "\n");
        while($input = fgets(STDIN, 10))
        {
            echo $input."\n";
            $connection->write($input);

        }
    });
    /*
    $input = new React\Stream\ReadableResourceStream(STDIN,$loop);
    $input->on("data",function ($data) use ($connection) {
       $connection->write($data);
    });*/
    //$output = fopen("./client.txt", "w");
    //$steam = new React\Stream\WritableResourceStream($output,$loop);
    //$connection->pipe($steam);



});

$loop->run();

最亮眼的是将文件描述符（标准输出流文件输出流）fd 包装成一个响应式流对象通过pipe实现管道功能而且生命周期相同会同时关闭。

Tags composer, reactive