Question

我在端口81上运行Apache。我的项目文件夹是MyPhpProject。在里面我有2个文件夹：Domain和Testing。

在 Domain 文件夹中，我有3个PHP文件：

BaseDomain.php，其中包含抽象类 BaseDomain
Location.php，其中包含从BaseDomain继承的具体类位置
Employee.php，其中包含从BaseDomain继承的具体类 Employee

Employee类有一个Location类的引用。

这是BaseDomain.php：

<?php
abstract class BaseDomain {

}
?>

这是Location.php：

<?php
$returnRequire = require 'BaseDomain.php';

class Location extends BaseDomain {

    private $locationIdInt;         
    private $codeNameString;        
    private $descString;        

    public function setLocationId($locationId) {
        $this->locationIdInt = $locationId;
    }
    public function getLocationId() {
        return $this->locationIdInt;
    }

    public function setCodeName($codeName) {
        $this->codeNameString = $codeName;
    }
    public function getCodeName() {
        return $this->codeNameString;
    }

    public function setDesc($desc) {
        $this->descString = $desc;
    }
    public function getDesc() {
        return $this->descString;
    }
}
?>

这是Employee.php：

<?php
$returnRequire = require 'BaseDomain.php';

class Employee extends BaseDomain {

    private $employeeIdString;          
    private $locationObject;            

    public function setEmployeeId($employeeId) {
        $this->employeeIdString = $employeeId;
    }
    public function getEmployeeId() {
        return $this->employeeIdString;
    }

    public function setLocation($location) {
        $this->locationObject = $location;
    }
    public function getLocation() {
        return $this->locationObject;
    }
}
?>

现在在 Testing 文件夹中我创建了一个Test_Employee.php，这是它的代码：

<?php
set_include_path('../Domain');

$getIncludePath = get_include_path();
echo "getIncludePath = " . $getIncludePath;
echo "<br>";

$returnRequire1 = require 'Location.php';
echo "returnRequire for Location.php = " . $returnRequire1;
echo "<br>";

$returnRequire2 = require 'Employee.php';
echo "returnRequire for Employee.php = " . $returnRequire2;
echo "<br>";
?>

当我尝试运行它http://localhost:81/MyPhpProject/Testing/Test_Employee.php时，我遇到了无法重新声明BaseDomain类的致命错误。这是我在浏览器中看到的：

getIncludePath = ../Domain

returnRequire for Location.php = 1

致命错误：无法在C：\ Program Files中重新声明类BaseDomain   （x86）\ Apache软件   基础\ Apache2.2 \ htdocs \ MyPhpProject \ Domain \ BaseDomain.php在线   2

我没有多次创建BaseDomain类。所以这个错误是奇怪的。有人可以解释为什么我收到错误消息？以及如何解决它。

感谢您的时间。

Answer 1

行$returnRequire1 = require 'Location.php';加载Location.php，后者又在行$returnRequire = require 'BaseDomain.php';中加载BaseDomain.php。然后，行$returnRequire2 = require 'Employee.php';加载Employee.php，它再次加载BaseDomain.php（行$returnRequire = require 'BaseDomain.php';）。 BaseDomain.php的第二次加载导致php尝试重新定义BaseDomain类，这是不允许的。

解决此问题的最简单方法是将require来电更改为require_once。这将确保每次运行时每个文件只加载一次，这将防止您遇到的错误。

Answer 2

BaseDomain.php：

<?php
abstract class BaseDomain {

}
?>

Location.php

<?php
class Location extends BaseDomain {

    private $locationIdInt;         
    private $codeNameString;        
    private $descString;        

    public function setLocationId($locationId) {
        $this->locationIdInt = $locationId;
    }
    public function getLocationId() {
        return $this->locationIdInt;
    }

    public function setCodeName($codeName) {
        $this->codeNameString = $codeName;
    }
    public function getCodeName() {
        return $this->codeNameString;
    }

    public function setDesc($desc) {
        $this->descString = $desc;
    }
    public function getDesc() {
        return $this->descString;
    }
}
?>

Employee.php：

<?php

class Employee extends BaseDomain {

    private $employeeIdString;          
    private $locationObject;            

    public function setEmployeeId($employeeId) {
        $this->employeeIdString = $employeeId;
    }
    public function getEmployeeId() {
        return $this->employeeIdString;
    }

    public function setLocation($location) {
        $this->locationObject = $location;
    }
    public function getLocation() {
        return $this->locationObject;
    }
}
?>

Test_Employee.php

<?php
set_include_path(__DIR__.'/MyPhpProject/Domain');
require 'BaseDomain.php';

$getIncludePath = get_include_path();
echo "getIncludePath = " . $getIncludePath;
echo "<br>";

$returnRequire1 = require 'Location.php';
echo "returnRequire for Location.php = " . $returnRequire1;
echo "<br>";

$returnRequire2 = require 'Employee.php';
echo "returnRequire for Employee.php = " . $returnRequire2;
echo "<br>";
?>

为什么我得到＆＃34;不能重新声明课程＆＃34;错误？

2 个答案: