How to use finalized in java

The finalized method is used to perform cleanup operations, such as closing files or releasing resources, before the object is recycled. It should be noted that the finalize() method is not guaranteed to be called, it should not be relied upon to release critical resources, and exceptions cannot be rethrown in this method.

Usage of finalized in Java

finalized is Java A rarely used garbage collection method that is called immediately before the object is collected by the garbage collector.

Purpose

The main purpose of finalized is to allow the object to perform cleanup operations before being recycled. For example, close a file, release resources, or perform other operations that must be performed when the object is no longer needed.

How to use

To use finalized, you need to override the finalize() method in the class. The method has a throws Throwable declaration, which means it can throw any exception.

@Override
protected void finalize() throws Throwable {
    // 在这里编写清理操作
}

Notes

You need to pay attention to the following when using finalized:

• Calling is not guaranteed : The garbage collector can choose not to call the finalize() method.
• Cannot rely on: You should not rely on the finalize() method to release critical resources or perform important operations.
• Performance overhead: Calling the finalize() method will bring some performance overhead.
• Exceptions should not be rethrown: finalize() Exceptions should not be rethrown in the method, otherwise it may cause the virtual machine to crash.

Alternatives

In most cases, use the built-in garbage collection mechanism (i.e. the try-with-resources statement or Closable interface) is more reliable and efficient than using finalized.

Conclusion

finalized is an uncommon method in Java, mainly used to perform cleanup operations before the object is recycled. However, it has its limitations and should not be relied upon to free up critical resources or perform important operations.

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