Spring Analysis of Error and Exception in Spring Boot Data Source Configuration

Problem Link：https://github.com/spring-projects/spring-framework/issues/30563

I think this is more like a bug, which will cause Spring to be unable to initialize beans. Looking at the following code example, as long as a bean like @ ConditionalOnClass (DruidDataSource. class) exists in the @ Configuration class, at runtime, if that class does not exist, it will cause other beans in the entire class to fail to initialize

`package com.lesson.commons.config.wrong;

import com.alibaba.druid.pool.DruidDataSource; import org.springframework.boot.autoconfigure.condition.ConditionalOnClass; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @configuration public class ClassNotFoundConfig { @bean public ExistingClass existingClass() { return new ExistingClass(); } @bean(name = "sparrow_default") @ConditionalOnClass(DruidDataSource.class) public DruidDataSource druidDataSource() { DruidDataSource druidDataSource = new DruidDataSource(); return druidDataSource; } }`

Comment From: snicoll

Duplicates #30563