Java8如何通过Stream对list对象某个属性去重

private static final List<SyncBalance> list = asList(
        new SyncBalance(BigDecimal.ZERO, "12345678", 0, 1, "GGBond", 32, 0),
        new SyncBalance(BigDecimal.ZERO, "22345678", 0, 1, "GGBond", 32, 0),
        new SyncBalance(BigDecimal.ZERO, "22345678", 1, 1, "GGBond", 32, 0),
        new SyncBalance(BigDecimal.ZERO, "22345678", 1, 1, "GGBond", 32, 0)
);

/**
 * 1. 对所有属性一样的数据进行去重
 */
public static void allColumnDistinct() {
    List<SyncBalance> allColumnDistinct = list.stream().distinct().collect(Collectors.toList());
}

/**
 * 2. 对单个属性去重，只返回去重的属性
 */
public static void columnDistinct() {
    List<String> columnDistinct = list.stream().map(SyncBalance::getMobile).distinct().collect(Collectors.toList());
}

/**
 * 3-1. 对单个属性一样的数据进行去重，下面是对`mobile`去重
 */
public static void oneColumnDistinctMethodOne() {
    List<SyncBalance> oneColumnDistinctMethodOne = list.stream().collect(Collectors.collectingAndThen(
            Collectors.toCollection(() -> new TreeSet<>(
                    Comparator.comparing(SyncBalance::getMobile))), ArrayList::new));
}

/**
 * 3-2. 对单个属性一样的数据进行去重,下面是对`mobile`去重(通过自定义属性去重方法)
 */
public static void oneColumnDistinctMethodTwo() {
    List<SyncBalance> oneColumnDistinctMethodTwo = list.stream().filter(distinctByKey(i -> i.getMobile())).collect(Collectors.toList());
}

/**
* list对象单个个字段去重(自定义属性)
* @param keyExtractor 去重的对象字段
* @return
* @param <T>
*/
public static <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) {
    Map<Object, Boolean> seen = new ConcurrentHashMap<>();
    return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
}

/**
 * 3-3. 对单个属性一样的数据进行去重,下面是对`mobile`去重
 * 利用TreeSet进行去重
 */
public static void oneColumnDistinctMethodThree() {
    TreeSet<SyncBalance> oneColumnDistinctMethodThree = new TreeSet<>(Comparator.comparing(i -> i.getMobile()));
    list.forEach(a -> oneColumnDistinctMethodThree.add(a));
}

/**
 * 4. 多个字段条件去重
 */
public static void twoColumnDistinct() {
    List<SyncBalance> twoColumnDistinct = list.stream().collect(Collectors.collectingAndThen(
            Collectors.toCollection(() -> new TreeSet<>(
                    Comparator.comparing(p -> p.getMobile() + ";" + p.getStatus()))), ArrayList::new));
}

/**
 * 验证的main方法
 * @param args
 */
public static void main(String[] args) {
    allColumnDistinct();
    columnDistinct();
    oneColumnDistinctMethodOne();
    oneColumnDistinctMethodTwo();
    oneColumnDistinctMethodThree();
    twoColumnDistinct();
}