Where did you get this bean?
summary
Explains exactly how Spring Boot actually creates and chooses beans: auto‑configuration classes listed in spring.factories register beans and proxies (e.g. Spring Data repositories), ASM‑based checks like ConditionalOnClass avoid loading types, and presence/absence checks like ConditionalOnProperty or ConditionalOnMissingBean control creation. Shows how @ConfigurationProperties gets bound, how configuration ordering and @EnableAutoConfiguration interact, and how to write focused tests that load only selected configs. Demonstrates concrete failure modes and how to debug them.
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chapters (5)
- 0:00Start
- 0:36Spring contexts are also called Spring loc containers, which are responsible for instantiating, configuring, and assembling beans by reading configuration metadata from XML, Java annotations, and/or Java code in the configuration files.
- 5:54Defining beans by annotating classes
- 10:20Configuration properties easier
- 19:00ASM is an all purpose Java bytecode manipulation and analysis framework. It can be used to modify existing classes or to dynamically generate classes, directly in binary form.
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