List或者arraylist去掉重複資料(物件也可以)
阿新 • • 發佈:2019-02-15
方法:將list或者arraylist中的資料載入到linkedhashset中 然後在載入到list或者arraylist中
測試用例如下:
public class TestSet { public static void main(String[] args) { List<Student> list1 = new ArrayList<Student>(); list1.add(new Student("張三","12")); list1.add(new Student("張三","12")); list1.add(new Student("李四","12")); list1.add(new Student("王五","15")); list1.add(new Student("張三","12")); list1.add(new Student("張三","13")); System.out.println(list1.toString()); Set<Student> set = new LinkedHashSet<Student>(); set.addAll(list1); List<Student> list2 = new ArrayList<Student>(); list2.addAll(set); System.out.println(list2.toString()); } }
物件:
public class Student { String name; String age; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((age == null) ? 0 : age.hashCode()); result = prime * result + ((name == null) ? 0 : name.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; Student other = (Student) obj; if (age == null) { if (other.age != null) return false; } else if (!age.equals(other.age)) return false; if (name == null) { if (other.name != null) return false; } else if (!name.equals(other.name)) return false; return true; } @Override public String toString() { return "Student [name=" + name + ", age=" + age + "]"; } public Student(String name, String age) { super(); this.name = name; this.age = age; } public Student() { // TODO Auto-generated constructor stub } }
結果