1. 程式人生 > >List或者arraylist去掉重複資料(物件也可以)

List或者arraylist去掉重複資料(物件也可以)

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