JVM Class Loading Security

The main ways JVM implements class loading security are as follows:

1. Parental delegation model: JVM adopts the parental delegation model to ensure the security of class loading. When a class needs to be loaded, it will first be delegated to the parent class loader for loading. Only when the parent class loader cannot load the class will it be loaded by the child class loader. This can prevent the same class from being loaded by multiple class loaders, ensuring the uniqueness of the class.
2. ClassLoader isolation: Class loaders in the JVM are isolated from each other, meaning that each class loader can only load classes that it has loaded itself and cannot access classes loaded by other class loaders. This helps prevent interference among different class loaders and ensures the security of class loading.
3. The bidirectional delegation of class loaders in JVM ensures the dependencies between class loaders, ensuring the integrity and correctness of the class loading process.

By the above means, JVM ensures the security of class loading, ensuring the uniqueness and correctness of classes, and preventing the loading and execution of malicious code.