Java ArrayList对象集合去重

import java.util.ArrayList;
import java.util.Iterator;

public class StringSampleDemo {
    public static void main(String[] args) {
        ArrayList al = new ArrayList();
        al.add(new Student("zhangsan1", 20, "男"));
        al.add(new Student("zhangsan1", 20, "男"));
        al.add(new Student("lilin1", 21, "女"));
        al.add(new Student("lilin1", 21, "女"));
        al.add(new Student("lisi", 25, "男"));

        al = getUniqueList(al);

        for (Object o : al) {
            Student s = (Student) o;
            System.out.println(s.getName() + "...." + s.getAge() + "...." + s.getSex());
        }

        /** 去重后的集合数据
         *
         * zhangsan1....20....男
         * lilin1....21....女
         * lisi....25....男
         */

    }

    /**
     * 去除重复对象
     *
     * @param al
     * @return
     */
    public static ArrayList getUniqueList(ArrayList al) {
        ArrayList tempAl = new ArrayList();

        Iterator it = al.iterator();
        while (it.hasNext()) {
            Object obj = it.next();
            if (!tempAl.contains(obj)) //不存在则添加
            {
                tempAl.add(obj);
            }
        }
        return tempAl;
    }
}


class Student {
    private String name;
    private int age;
    private String sex;

    public Student(String name, int age, String sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    /**
     * 重点是重写比较方法
     *
     * @param obj
     * @return
     */
    @Override
    public boolean equals(Object obj) {
        if (obj instanceof Student) {
            Student s = (Student) obj;
            return this.name.equals(s.name) && this.age == s.age && this.sex.equals(s.sex);
        } else {
            return false;
        }
    }
}

  

原文地址:https://www.cnblogs.com/smartsmile/p/11613006.html