Building a project from a tutorial and building one from scratch feel nothing alike. In a tutorial every decision is already made for you. The package structure, the class names, what goes in the ...

𝗧𝘄𝗼 𝗕𝘂𝗴𝘀 𝗧𝗵𝗮𝘁 𝗧𝗮𝘂𝗴𝗵𝘁 𝗠𝗲 𝗠𝗼𝗿𝗲 𝗧𝗵𝗮𝗻 𝗔𝗻𝘆 𝗧𝘂𝘁𝗼𝗿𝗶𝗮𝗹 I learned more from two bugs than from any tutorial. These errors showed me the gap between how tools work and how ...

Java 基本数据类型的包装类型的大部分都用到了缓存机制来提升性能。 Byte, Short, Integer, Long 这 4 种包装类默认创建了数值 [-128，127] 的相应类型的缓存数据， Character 创建了数值在 [0,127] 范围的缓存数据， Boolean 直接返回 TRUE or FALSE。