Java Puzzlers by Bloch & Gafter

Summary of most important things in this book:

• To escape characters in regular expression use Pattern.quote("."). To change replacement string Matcher.quaoteReplacement(String).
  
• In java are statemant labels
• Special values:
  

Double.NaN
Double.POSITIVE_INFINITY

• Be careful:

Integer.MIN_VALUE = -Integer.MIN_VALUE
Long.MIN_VALUE = - Long.MIN_VALUE

• Java exception checking is not enforced be the virtual machine
• Class.newInstance can throw checked exceptions that it does not declare
• Generic type information is checked at compile time not at runtime.
• When a program calls a static method, the method to be invoked is selected at compile-time, based on compile-time type of a qualifier
• Static methods annnot be overridden, they can only be hidden
• Never call overridable methods from constuctors
• AtomicLong - object with implementation for synchonisation
• You must override hashcode() whenever you override equals
• Integer literals begining with 0 are in interpreted as octal values
• Math.abs is not guaranteed to return nonnegative result. For Integer MIN_VALUE and for Long MIN_VALUE it does not
• Methods in object are overwritten and fields are only hidden but can be other types.
• It is possible to hide variables, nested types and static methods.
• A package-private method cannot be directly overridden by a method in a different package
• Thread.join calls Object.wait on the Thread instance representing the Thread being joined. This releases the lock for the duration of the wait
• You cannot legally access a member of a nonpublic type from an other package
• The constructor of a non-static nested class is compiled such that it has as its first parameter an additional implicid parameter representing the immediately enclosing instance. So avoid using reflection to instantiate inner classes
• PrintStream.write(int) is the only output method that does not flush a PrintStream
• You must drain the output stream of a child process in order to ensure its termination. The same goes for the error stream.
• Calling Thread.interrupted always clears the interrupted status of the current thread
• References to constant fields are resolved at compile time to the constant values they denote.