Java集合排序

List<Long> musicIds = new ArrayList<>();
musicIds.add(0, 1l);
musicIds.add(1, 10l);
musicIds.add(1, 2l);
musicIds.add(1, 8l);
musicIds.add(1, 4l);
System.out.println("排序前：" + musicIds.toString());
Collections.sort(musicIds);
System.out.println("从小到大排序后：" + musicIds.toString());

public static void sort2(){
    List<DataResponse> dataResponseList = Lists.newArrayList();
    dataResponseList.add(new DataResponse(1001L,222));
    dataResponseList.add(new DataResponse(1002L,444));
    dataResponseList.add(new DataResponse(1003L,111));
    dataResponseList.add(new DataResponse(1004L, 888));
    Collections.sort(dataResponseList, new Comparator<DataResponse>() {
        @Override
        public int compare(DataResponse o1, DataResponse o2) {
            return Integer.compare(o1.dataType, o2.dataType);
        }
    });

    System.out.println("按dataType排序：\n" + dataResponseList.toString());

    Collections.sort(dataResponseList, new Comparator<DataResponse>() {
        @Override
        public int compare(DataResponse o1, DataResponse o2) {
            return Double.compare(o1.dataId,o2.dataId);
        }
    });

    System.out.println("\n按dataId排序：\n"+dataResponseList.toString());
}

static class DataResponse{
    Long dataId;
    Integer dataType;

    public DataResponse() {
    }

    public DataResponse(Long dataId, Integer dataType) {
        this.dataId = dataId;
        this.dataType = dataType;
    }

    public Long getDataId() {
        return dataId;
    }

    public void setDataId(Long dataId) {
        this.dataId = dataId;
    }

    public Integer getDataType() {
        return dataType;
    }

    public void setDataType(Integer dataType) {
        this.dataType = dataType;
    }

    @Override
    public String toString() {
        return "DataResponse{" +
                "dataId=" + dataId +
                ", dataType=" + dataType +
                ‘}‘;
    }
}