T.I.L_221222

What’s New for Today

1. Effective Java
   • general programming
     • minimize the scope of local variables
       • minimizing error probability
       • make program predictable
     • prefer for-each loops
       • internal iterator, type convertion
     • know and use libraries
       • most of the codes are already implemented in libraries, and also it is high-quality
     • avoid float and double for exact computation
       • rather use bigdecimal
       • or convert to smaller units
     • prefer primitive types rather than boxed primitives
       • performance issues: autobox/unboxing
       • nullability
     • avoid strings to represent value
       • not correctly work with equals, hashcode
       • converting into/outo string causes performance issues
     • beware of string concatenation
       • due to immutable instance, need copy
     • refer objects by interfaces
       • make program flexble
       • OCP, DIP
     • prefer interfaces than reflection
       • runtime errors < compile time errors
     • use native methods judiciously
       • it may have better performance, but less portable and unpredictable(can cause memory corruption)
     • optimize judiciously
       • too much variables to consider
       • it may not have expected results
     • secure naming conventions
       • typographical and grammer conventions
2. MongoDB
   • Basic
   • Structure
   • Installation