Bit array of Java

Write a small thing, to repeat the number, use a bit array, although Java has provided a bitset, but preface, and wrote a simple

The principle is not written, a lot of online

1 ImportJava.util.Iterator;2 ImportJava.util.function.BiConsumer;3 4  Public classBitArrayImplementsIterable<boolean>{5     //represents the value of the 1<<n, improving efficiency without each calculation6     Private Final byte[] MASK =New byte[]{1,2,4,8,16,32,64, (byte) 128};7     byte[] bits;8     intMax = 0;9     Ten     /** One * Construct a bit array A      * @paramMax maximum number of digits -      */ -      PublicBitArray (intmax) { the          This. Max =Max; -         intLen = max/8 + 1; -          -BITS =New byte[Len]; +     } -      +     /** A * Set the value of nth bit at      * @paramIndex bit Indexes -      * @paramValue Values -      */ -      Public voidSetintIndexBooleanvalue) { -         inti = INDEX/8; -         intMove = index% 8; in          -Bits[i] = (byte) (Bits[i] |Mask[move]); to     } +      -     /** the * Get the value of nth bit *      * @paramIndex bit Indexes $      * @returnPanax Notoginseng      */ -      Public BooleanGetintindex) { the         inti = INDEX/8; +         intMove = index% 8; A          the         return(Bits[i] & mask[move]) = =Mask[move]; +     } -      $     /** $ * Show All bits -      */ -      Public voidShow () { the          for(inti=0; i<bits.length; i++){ -             byteb =Bits[i];Wuyi              for(intbitindex=0; bitindex<8;bitindex++){ theSystem.out.print (((b>>bitindex) & 1) + ""); -             } Wu System.out.println (); -         } About     } $  -     /** - * provides traversal interface -      */ A      PublicIterator<boolean>iterator () { +         return NewIterator<boolean>(){ the             Private inti = 0; -  $              Public BooleanHasnext () { the                 returnI <=Max; the             } the  the              PublicBoolean Next () { -                 returnGet (i++); in             } the              the         }; About     } the      the     /** the * Traversal, lazy use of the new interface JAVA8 +      * @param Fun -      */ the      Public voidForEach (biconsumer<integer,boolean>Fun ) {Bayi         intTotal = 0; the          for(inti=0; i<bits.length; i++){ the             byteb =Bits[i]; -              for(intbitindex=0; Bitindex<8 && total<=max;bitindex++,total++){ -Fun.accept (Total, ((B>>bitindex) & 1) = = 1); the             } the         } the     } the}

How to use:

 Public Static voidMain (string[] args)throwsexception{BitArray bits=NewBitArray (18); Bits.set (18,true); System.out.println ("Position 3:" + bits.get (3)); System.out.println ("Position:" + bits.get (18)); System.out.println ("--------------------------"); //Traversal mode one    inti = 0;  for(Boolean result:bits) System.out.println (i++ + " : " +result); System.out.println ("--------------------------"); //Traversal mode twobiconsumer<integer,boolean> fun = (index, value){System.out.println (index+ " : " +value);            }; Bits.foreach (fun);}

Output Result:

/* position 3:falseposition 18:true--------------------------0:false1:false2:false3:false4:false5:false6 : False7:false8:false9:false10:false11:false12:false13:false14:false15:false16:false17:false18:tru E--------------------------0:false1:false2:false3:false4:false5:false6:false7:false8:false9:false10: False11:false12:false13:false14:false15:false16:false17:false18:true* *

Bit array of Java