不同的保留策略如何影响我的注释? [英] How do different retention policies affect my annotations?

问题描述

谁能清楚地解释java.lang.annotation.RetentionPolicy 常量SOURCE、CLASS 和<代码>运行时间?

我也不太确定保留注释"这个词是什么意思.

解决方案

• RetentionPolicy.SOURCE:期间丢弃编译.这些注释不编译后有意义完成，所以它们不会被写入字节码.
  示例:@Override、@SuppressWarnings

• RetentionPolicy.CLASS:期间丢弃类负载.做的时候有用字节码级别的后处理.让人有些意外的是，这是默认.

• RetentionPolicy.RUNTIME:不要丢弃.注释应该是可在运行时进行反射.示例:@Deprecated

来源:旧网址现已失效

Can anyone explain in a clear way the practical differences between the java.lang.annotation.RetentionPolicy constants SOURCE, CLASS, and RUNTIME?

I'm also not exactly sure what the phrase "retaining annotation" means.

解决方案

• RetentionPolicy.SOURCE: Discard during the compile. These annotations don't make any sense after the compile has completed, so they aren't written to the bytecode.
  Example: @Override, @SuppressWarnings

• RetentionPolicy.CLASS: Discard during class load. Useful when doing bytecode-level post-processing. Somewhat surprisingly, this is the default.

• RetentionPolicy.RUNTIME: Do not discard. The annotation should be available for reflection at runtime. Example: @Deprecated

Source: The old URL is dead now hunter_meta and replaced with hunter-meta-2-098036. In case even this goes down, I am uploading the image of the page.

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