看了设计模式之美，记录一次看书心得

Posted 2022-02-02 mr.杰瑞

未优化的代码：

class IdGenerator 
  public static function insertLog()
      return '记录日志';
  
  public static function generate() 
    $id = "";
    try 
      $hostName = '127.0.0.1';
      $count = 0;
      while ($count < 8) 
          $randomAscii = rand(1,122);
        if ($randomAscii >= 48 && $randomAscii <= 57) 
            $randomChars[$count] = (string)chr($randomAscii);
            $count++;
         else if ($randomAscii >= 65 && $randomAscii <= 90) 
            $randomChars[$count] = (string)chr($randomAscii);
            $count++;
         else if ($randomAscii >= 97 && $randomAscii <= 122) 
            $randomChars[$count] = (string)chr($randomAscii);
            $count++;
        
      
      $id = printf("%s-%d-%s", $hostName,
              time(), implode("",$randomChars));
     catch (\\Exception $e) 
        self::insertLog();
        throw $e;
    
    return $id;
  

$id = (new IdGenerator)::generate();
var_dump($id);

• 目录设置是否合理、模块划分是否清晰、代码结构是否满足“高内聚、松耦合”？ 是否遵循经典的设计原则和设计思想（SOLID、DRY、KISS、YAGNI、LOD等）？ 设计模式是否应用得当？是否有过度设计？
• 代码是否容易扩展？如果要添加新功能，是否容易实现？
• 代码是否可以复用？是否可以复用已有的项目代码或类库？是否有重复造轮子？
• 代码是否容易测试？单元测试是否全面覆盖了各种正常和异常的情况？
• 代码是否易读？是否符合编码规范（比如命名和注释是否恰当、代码风格是否一致等）

优化后

<?php
interface IdGenerator

    public function generate();


interface LogTraceIdGenerator extends IdGenerator

    public function insertLog();


class RandomIdGenerator implements LogTraceIdGenerator

    /**
     * 日志
     */
    public function insertLog()
    
        // TODO: Implement insertLog() method.
    

    /**
     * @return int
     * @throws Exception
     */
    public function generate()
    
        $substrOfHostName = $this->getLastfieldOfHostName();
        $currentTimeMillis = time();
        $randomString = $this->generateRandomAlphameric(8);
        $id = printf("%s-%d-%s", $substrOfHostName, $currentTimeMillis, $randomString);
        return $id;
    

    /**
     * @return String
     */
    private function getLastfieldOfHostName()
    
        $substrOfHostName = null;
        try 
            $hostName = '127.0.0.1';
            $substrOfHostName = $this->getLastSubstrSplittedByDot($hostName);
         catch (\\Exception $e) 
            $this->insertLog();
            throw $e;
        
        return $substrOfHostName;
    

    /**
     * @param String $hostName
     * @return String
     */
    protected function getLastSubstrSplittedByDot(String $hostName)
    
        //todo 这里是获取服务器地址逻辑
        return $hostName;
    

    /**
     * 获取随机字符
     * @param int $length
     * @return string
     */
    protected function generateRandomAlphameric(int $length)
    
        while ($count < $length) 
            $maxAscii = 'z';
            $randomAscii = rand(0, ord($maxAscii));
            $isDigit= $randomAscii >= '0' && $randomAscii <= '9';
            $isUppercase= $randomAscii >= 'A' && $randomAscii <= 'Z';
            $isLowercase= $randomAscii >= 'a' && $randomAscii <= 'z';
            if ($isDigit|| $isUppercase || $isLowercase) 
                $randomChars[$count] = (string) ($randomAscii);
                ++$count;
            
        
        return implode('', $randomChars);