tjwudi / java_recover

Recover my Java skills

Java Recover

Recover my Java skills ...

Notes

Garbage collection is not destruction

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Overload: Same class, diff methods with same name and diff params. Override: Diff class, same method.

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Q: Why is String class considered immutable? A: The String class is immutable, so that once it is created a String object cannot be changed. Since String is immutable it can safely be shared between many threads ,which is considered very important for multithreaded programming.

TODO

1. Regex
2. Multi-threading
3. *Set, *Map, *List ...
4. Encoding

Others

1. Linux commands

Question

1. Given a log file with format: " 1,2,start 2,3,end 2,4, start """" where each tuple is a (job_id,time,option) where option is start or end, find a way to map concurrent processes to each other