Found a total of 10000 related content
How to implement automatic loading of classes in PHP?
Article Introduction：In PHP, automatically loading classes are implemented through the __autoload or spl_autoload_register function. 1. The __autoload function has been abandoned, 2. The spl_autoload_register function is more flexible, supports multiple automatic loading functions, and can handle namespace and performance optimization.
2025-05-15
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520
Understanding Java Class Loading Mechanism
Article Introduction：The Java class loading mechanism is the core of the runtime, and understanding it helps to troubleshoot class conflicts, class failure, and other problems. Its basic process is divided into three stages: loading, linking (verification, preparation, parsing) and initialization, and is loaded on demand using LazyLoading. Class loaders include BootstrapClassLoader, ExtensionClassLoader, ApplicationClassLoader and custom class loaders, and use the parent delegation model to ensure uniqueness and security. Frequently asked questions include ClassNotFoundException, NoClassDefFoundError, class duplicate loading, resource leakage, etc. Use suggestions include checking
2025-07-19
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883
What is class loading in Java?
Article Introduction：Java's class loading is a mechanism for JVM to load classes dynamically at runtime. Its core works by three class loaders at hierarchy and delegate model. 1. BootstrapClassLoader is responsible for loading the core class library; 2. ExtensionClassLoader is used to load the extension library; 3. ApplicationClassLoader loads classes in the application classpath. Class loading adopts on-demand loading strategies, which helps reduce memory overhead and improve startup efficiency. It is particularly critical in large applications (such as Spring, OSGi), web servers and plug-in systems, and can realize dynamic loading and isolation of classes. If the configuration is not correct, ClassNotFoundEx may be triggered
2025-06-30
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664
What is the class loading delegation model?
Article Introduction：Java's class loading delegate model is a hierarchical structure mechanism that ensures that classes are loaded by the most trusted class loader. 1. BootstrapClassLoader loads core Java classes (such as java.lang, java.util); 2. ExtensionClassLoader is responsible for loading classes in the extension directory and delegating BootstrapClassLoader; 3. ApplicationClassLoader loads classes in the application classpath and delegates ExtensionClassLoader. When the class needs to be loaded, the request starts from the ApplicationClassLoader and goes up step by step
2025-06-29
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442
How does Java class loading work (Bootstrap, Extension, System ClassLoaders)?
Article Introduction：Java's class loading mechanism is composed of Bootstrap, Extension and SystemClassLoaders, and uses a parent delegation model to ensure the security and unique loading of classes. BootstrapClassLoader is responsible for loading core class libraries such as rt.jar; ExtensionClassLoader loads extension libraries such as jar under jre/lib/ext; SystemClassLoader loads classes on the application classpath. When the class is loaded, the parent loader is given priority to find the class. If none of them are found, a ClassNotFoundException will be thrown. Understanding this mechanism can help troubleshoot conflicts, avoid security risks and improve
2025-07-12
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520
How to create and use a simple autoloader with PSR-4 in PHP?
Article Introduction：The answer is to create a PSR-4 autoloader that requires mapping the namespace to the directory. 1. Define the namespace App\corresponding to src/directory; 2. Create class files such as src/Controller/HomeController.php; 3. Use spl_autoload_register to register the automatic loading function to convert the namespace to file path; 4. Introduce an automatic loader in index.php and instantiate the class to achieve automatic loading.
2025-09-09
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202
How do I fix 'Autoload error' after installing packages with Composer?
Article Introduction：When encountering Composer's "Autoloaderror", the first thing to do is to clarify the core of the problem: PHP cannot find the required class through automatic loading. The following are the solutions: 1. Run composerdump-autoload to regenerate the automatic loading file, and clear the cache if necessary; 2. Check whether the case of the class name and file path match, especially on case-sensitive systems; 3. Check the PSR-4 automatic loading configuration in composer.json to ensure that the namespace and directory path are correct; 4. Try to uninstall and reinstall the problem package or clean the vendor directory and then reinstall it; 5. Troubleshoot duplicate class names or conflicting files. In most cases
2025-08-05
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630
Solve syntax errors when dynamically loading a namespace class in Laravel 8
Article Introduction：This article discusses common problems and solutions for dynamically loading namespace classes in Laravel 8, especially how to avoid syntax errors caused by direct string splicing of new keywords. We will introduce two main methods: building the complete class name and instantiating it through variables, and using Laravel's app() helper function to implement dependency injection instantiation to ensure the robustness and maintainability of the code.
2025-08-29
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478
How to Access Child Class Methods from a Parent Class in PHP?
Article Introduction：PHP: Accessing Child Class Methods from a Parent ClassOften, when working with inheritance in PHP, developers encounter the need to access functions from a child class within the parent class. This can be achieved through a powerful mechanism: abstra
2024-10-19
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