List存储对象根据某个属性去重的三种方法

1、废话不多说直接上代码，第一种采取的是重写hashCode和equals的方法，后面两种都是使用java8新特性
2、对象代码：

@Data
public class ImportResume {
    private Integer age;
    private String phone;
    //用于去重
    @Override
    public boolean equals(Object object){
        ImportResume importResume=(ImportResume)object;
        return phone.equals(importResume.phone);
    }
    @Override
    public int hashCode(){
        String in = phone;
        return in.hashCode();

    }
}

3、java代码：

public void save(List<ImportResume> list) {
        long l = System.currentTimeMillis();
        System.out.println("去重前"+list.size());
        Set<ImportResume> set=new HashSet<>(list);
        System.out.println("set"+set.size());

        List<ImportResume> resumeList=new ArrayList<>(set);
        long l1 = System.currentTimeMillis();
        long l2 = l1 - l;
        System.out.println("去重后"+resumeList.size()+"时间:"+l2);
        long l3 = System.currentTimeMillis();
        ArrayList<ImportResume> collect = list.stream().collect(Collectors.collectingAndThen(Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(ImportResume::getPhone))), ArrayList::new));
        long l4 = System.currentTimeMillis();
        long l5 = l4 - l3;
        System.out.println("炫酷的stream"+collect.size()+"时间:"+l5);
        long l7 = System.currentTimeMillis();
        List<String> names = new ArrayList<>();
        List<ImportResume> collect1 = list.stream().filter(item -> {
            boolean flag = !names.contains(item.getPhone());
            names.add(item.getPhone());
            return flag;
        }).collect(Collectors.toList());
        long l8 = System.currentTimeMillis();
        long l6 = l8 - l7;
        System.out.println("炫酷的lambada"+collect1.size()+"时间:"+l6);
    }

测试得到第一种方法速度最快，下来是第二种