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FAQ

javac 乱码​

强制使用 UTF-8

javac -J-Dfile.encoding=UTF-8

选择 JUL 类逻辑​

graph TD

    Start[选择JUL类] --> KVorV[KV or Value only?]
    KVorV --Value--> Duplicate[是否允许重复?]
    Duplicate --Yes--> Sync[是否线程同步?]
    Duplicate--No-->Ordered[是否有序?]
    Ordered--No-->HasSet
    Ordered--Yes-->ByInsertOrValue[插入排序还是值排序?]
    ByInsertOrValue--Insert-->LinkedHashSet
    ByInsertOrValue--Value-->TreeSet
    Sync--Yes-->LIFO[LIFO堆栈操作?]
    LIFO--Yes-->Stack
    LIFO--No-->Vector
    Sync --No--> RandomAccess[随机访问?]
    RandomAccess--Yes-->ArrayList
    RandomAccess --No--> SeqAccess[顺序访问?]
    SeqAccess --Yes--> LinkedList
    SeqAccess --No--> Queue[队列操作?]
    Queue --No--> ArrayList
    Queue --Yes--> FastQueue[快速队列?]
    FastQueue --No--> LinkedList
    FastQueue --Yes--> ArrayDeque

    KVorV--KV-->EntryOrdered[有序?]
    EntryOrdered--Yes-->EntryOrderedBy[顺序基于?]
    EntryOrderedBy--Insert-->LinkedHashMap
    EntryOrderedBy--Key-->KVSync[线程同步?]
    KVSync--Yes-->HashTable
    KVSync--No-->TreeMap
    EntryOrdered--No-->Cache[作为缓存/Value构建成本高?]
    Cache--Yes-->WeakHashMap
    Cache--No-->Equals[equals/==?]
    Equals--equals-->HashMap
    Equals--==-->IdentityHashMap

Why is generic of a return type erased when there is an unchecked conversion of a method parameter in Java 8?​

Collection http://fastutil.di.unimi.it/ http://pcollections.org/ https://github.com/hrldcpr/pcollections

https://mvnrepository.com/artifact/org.eclipse.collections/eclipse-collections https://github.com/eclipse/eclipse-collections

http://java-performance.info/hashmap-overview-jdk-fastutil-goldman-sachs-hppc-koloboke-trove-january-2015/

https://mvnrepository.com/open-source/collections

<dependency>
    <groupId>com.carrotsearch</groupId>
    <artifactId>hppc</artifactId>
    <version>0.8.1</version>
</dependency>

https://github.com/carrotsearch/hppc

Proxy performance​

https://stackoverflow.com/q/1856242/1870054