Java Object Creation Process Interview Review

This document analyzes the Java object creation process, its core steps, structure, and practical operations, combined with real-world scenarios. It also provides strategies for handling in-depth interviews. Each knowledge point is centered around a specific scenario, avoiding empty, clichéd narratives.

1. Class Loading Phase

Scenario: Debugging a Spring Boot application startup problem Suppose you’ve developed a Spring Boot application that throws a NoClassDefFoundError or ClassNotFoundException during startup, indicating that class loading may have failed. We need to analyze the class loading phase to locate the problem.

A. Why do we need class loading?

Class loading is the first step in the JVM running a Java program. It ensures that class definitions (.class files) are correctly loaded into memory for subsequent object creation. If the class is not loaded, the JVM does not know how to construct the object. In the above scenario, NoClassDefFoundError may be caused by missing dependencies or classpath errors. Inspection and verification during the class loading phase can help us locate the problem.

B. Class loading structure and practical operation