Step By Step(Java 集合篇) (二)

61 ArrayList arrayList = new ArrayList();

62 arrayList.add("1");

63 arrayList.add("2");

64 arrayList.add("3");

65 arrayList.add("4");

66 arrayList.add("5");

67 List lst = arrayList.subList(1, 3);

68 for (int i = 0; i < lst.size(); i++)

69 System.out.println(lst.get(i));

70 // remove one element from sub list

71 String obj = lst.remove(0);

72 System.out.println(obj + " is removed");

73 for (String str: arrayList)

74 System.out.println(str);

75 //get object array with normal method

76 Object[] objArray = arrayList.toArray();

77 for (Object obj1 : objArray)

78 System.out.println(obj1);

79 //get object array with generic method

80 String[] strArray = arrayList.toArray(new String[0]);

81 for (String str : strArray)

82 System.out.println(str);

83 }

84

85 public static void showListIterator() {

86 ArrayList aList = new ArrayList();

87 aList.add("1");

88 aList.add("2");

89 aList.add("3");

90 aList.add("4");

91 aList.add("5");

92

93 ListIterator listIterator = aList.listIterator();

94 while (listIterator.hasNext()) {

95 System.out.println(listIterator.next());

96 System.out.println("Previous: " + listIterator.previousIndex());

97 System.out.println("Next: " + listIterator.nextIndex());

98 }

99 while (listIterator.hasPrevious()) {

100 System.out.println(listIterator.previous());

101 System.out.println("Previous: " + listIterator.previousIndex());

102 System.out.println("Next: " + listIterator.nextIndex());

103 }

104 listIterator = aList.listIterator(2);

105 listIterator.next();

106 listIterator.set("100");

107 listIterator.next();

108 listIterator.remove();

109 for (String str : aList)

110 System.out.println(str);

111

112 if (aList.contains("4"))

113 System.out.println("True");

114 else

115 System.out.println("False");

116 }

117

118 public static void showFillAndReplace() {

119 ArrayList arrayList = new ArrayList();

120 arrayList.add("A");

121 arrayList.add("B");

122 arrayList.add("A");

123 arrayList.add("C");

124 arrayList.add("D");

125 Collections.replaceAll(arrayList, "A", "Replace All");

126 System.out.println(arrayList);

127 Collections.fill(arrayList, "REPLACED");

128 System.out.println(arrayList);

129 }

130

131 public static void showCollectionOperation() {

132 List colours = new ArrayList();

133 colours.add("red");

134 colours.add("green");

135 colours.add("blue");

136

137 System.out.println(colours);

138 Collections.swap(colours, 0, 2);

139 System.out.println(colours);

140

141 Collections.reverse(colours);

142 System.out.println(colours);

143

144 Collections.so