Java反射爲何慢

Because reflection involves types that are dynamically resolved, certain Java virtual machine optimizations can not be performed. Consequently, reflective operations have slower performance than their non-reflective counterparts, and should be avoided in sections of code which are called frequently in performance-sensitive applications.

反射是動態的對類型、方法進行解析，確定是會比直接調用慢一點。jvm沒法優化

java反射機制，是在運行狀態中，對於任何一個類，都可以訪問這個類的全部屬性和方法，同時任何一個對象也都可以調用它的任意一個方法和屬性，這個功能稱爲java語言的反射機制。