/匹配所有 allMatch
@Test
public void allMatchTest() {
  boolean b = list.stream()
      //所有的商品價(jià)格都大于40
      .allMatch(sku -> sku.getSkuPrice() > 40);
  System.out.println(b);
  /** 返回值
   * true
   */
}

//任意匹配 anymMatch
@Test
public void anyMatchTest() {
  boolean b = list.stream()
      //只要有一個(gè)totalNum數(shù)量為3就反回true
      .anyMatch(sku -> sku.getTotalNum() == 3);
  System.out.println(b);
  /** 輸出的結(jié)果：
   * true
   */
}

//不匹配 noneMatch
@Test
public void noneMatchTest() {
  boolean b = list.stream()
      //沒(méi)有totalNum為2的，所以返回值為true，
      .noneMatch(sku -> sku.getTotalNum() == 2);
  System.out.println(b);
  /**
   * 沒(méi)有匹配才選true
   */
}

//查找首個(gè) findFirst
@Test
public void findFirstTest() {
  //我自己的Optional里面有介紹,,findFirst()方法，只要有第一個(gè)就返回
  Optional<Sku> first = list.stream().findFirst();
  //從Optional里面取出來(lái)值
  Sku sku = first.get();
  //比json格式輸出結(jié)果
  System.out.println(JSON.toJSONString(sku,true));
  /**
   * {
   * "skuCategory":"ELECTRONICS",
   * "skuId":100001,
   * "skuName":"無(wú)人機(jī)",
   * "skuPrice":4999.0,
   * "totalNum":1,
   * "totalPrice":4999.0
   * }
   */
}

//查找任意 findAny
@Test
public void findAnyTest() {
  //從list中任意取出來(lái)一個(gè)
  Optional<Sku> any = list.stream().findAny();
  //從Optional里面取值
  Sku sku = any.get();
  //以json輸出結(jié)果
  System.out.println(JSON.toJSONString(sku, true));
  /**
   * {
   * "skuCategory":"ELECTRONICS",
   * "skuId":100001,
   * "skuName":"無(wú)人機(jī)",
   * "skuPrice":4999.0,
   * "totalNum":1,
   * "totalPrice":4999.0
   * }
   */
}