查找两个列表之间的差异并添加加减是一种更有效的方法

Question

我有两个具有相同数据的列表，但第一个列表的措辞可能略有不同。 我确保字段不匹配。如果他们不这样做，那么我在数组中的第一个单词中添加一个加号，在第二个数组中的第二个单词中添加一个减号。

我只是在迭代列表，我有很多 ifs。我还需要做其他数据点，ifs 可能会变得很长。有没有更有效的方法来做到这一点？ 我不擅长 java 8+ 和流。用流来做会更好吗？如果是这样，我该怎么做？可以举个例子吗？

提前谢谢你！！！我真的需要帮助，但我希望我的心碎了！

List<ExteriorColor> f1 = vinResponseOne.getResult().getExteriorColors();
List<ExteriorColor> f2 = vinResponseTwo.getResult().getExteriorColors();

first = vinResponseOne.getResult().getExteriorColors();
second = vinResponseTwo.getResult().getExteriorColors();



private void compareExteriorColors(List<ExteriorColor> f1, List<ExteriorColor> f2){

    for(int i =0; i< f1.size(); i++) {

        if (!f1.get(i).getDescription().equals(f2.get(i).getDescription())) {
            final String added = "+ " + f1.get(i).getDescription();
            final String original = "- " + f2.get(i).getDescription();
            first.get(i).setDescription(added);
            second.get(i).setDescription(original);
        }

         if (!f1.get(i).getGenericDesc().equals(f2.get(i).getGenericDesc())) {
            final String  added = "+ " + f1.get(i).getGenericDesc();
            final String original = "- " + f2.get(i).getGenericDesc();
            first.get(i).setGenericDesc(added);
            second.get(i).setGenericDesc(original);
        }

        if (!f1.get(i).getColorCode().equals(f2.get(i).getColorCode())) {
            final String added = "+ " + f1.get(i).getColorCode();
            final String original = "- " + f2.get(i).getColorCode();
            f1.get(i).setColorCode(added);
            f2.get(i).setColorCode(original);
        }

        if (f1.get(i).getInstallCause() != null) {
            if (!f1.get(i).getInstallCause().equals(f2.get(i).getInstallCause())) {
                final String added = "+ " + f1.get(i).getInstallCause();
                final String original = "- " + f2.get(i).getInstallCause();
                first.get(i).setInstallCause(added);
                second.get(i).setInstallCause(original);
            }
        }

        if (!f1.get(i).getPrimary().equals(f2.get(i).getPrimary())) {
            final String added = "+ " + f1.get(i).getPrimary();
            final String original = "- " + f2.get(i).getPrimary();
            first.get(i).setPrimary(added);
            second.get(i).setPrimary(original);
        }

        if (!f1.get(i).getRgbValue().equals(f2.get(i).getRgbValue())) {
            final String added = "+ " + f1.get(i).getRgbValue();
            final String original = "- " + f2.get(i).getRgbValue();
            first.get(i).setRgbValue(added);
            second.get(i).setRgbValue(original);
        }

        if (!f1.get(i).getStyles().equals(f2.get(i).getStyles())) {
            List<String> styleFirst = new ArrayList<>();
            List<String> styleSecond = new ArrayList<>();
            final String added = "+ " + f1.get(i).getStyles();
            final String original = "- " + f2.get(i).getStyles();
            styleFirst.add(added);
            styleSecond.add(original);
            first.get(i).setStyles(styleFirst);
            second.get(i).setStyles(styleSecond);
        }

        if (!f1.get(i).getType().equals(f2.get(i).getType())) {
            String added = "+ " + f1.get(i).getType();
            String original = "- " + f2.get(i).getType();
            first.get(i).setType(added);
            second.get(i).setType(original);
        }

    }
    
}

它最终的样子。

我稍后会转换成 json。

Answer 1

class User { //Considering a simple class with only 2 fields for brevity
  private String userName;
  private String password;

  User(String userName, String password) {
    this.userName = userName;
    this.password = password;
  }

  public String getUserName() {
    return userName;
  }

  public void setUserName(String userName) {
    this.userName = userName;
  }

  public String getPassword() {
    return password;
  }

  public void setPassword(String password) {
    this.password = password;
  }

  @Override
  public String toString() {
    return "User{" + "userName='" + userName + '\'' + ", password='" + password + '\'' + '}';
  }
}

public class S14 {
  public static void main(String[] args) {
    User user1 = new User("Anees", "pwd");
    User user2 = new User("Anees1", "pwd");
    List<User> userList1 = new ArrayList<>(Arrays.asList(user1, user2));
    User user3 = new User("Anees2", "pwd");
    User user4 = new User("Anees3", "pwd");
    List<User> userList2 = new ArrayList<>(Arrays.asList(user3, user4));
    // Assuming both Lists are of same size
    IntStream.range(0, userList1.size())
        .forEach(
            i -> {
              User firstListUser = userList1.get(i);
              User secondListUser = userList2.get(i);
              //HERE GOES THE MAIN PART
              compareStringsAndProcessElement(
                  firstListUser::getUserName,
                  secondListUser::getUserName,
                  (s, s2) -> !s.equals(s2),
                  firstListUser::setUserName,
                  secondListUser::setUserName);

              compareStringsAndProcessElement(
                  firstListUser::getPassword,
                  secondListUser::getPassword,
                  (s, s2) -> !s.equals(s2),
                  firstListUser::setPassword,
                  secondListUser::setPassword);
              //AND SO ON!
            });
    System.out.println(userList1);
    System.out.println(userList2);
  }

  private static void compareStringsAndProcessElement(
      Supplier<String> element1,
      Supplier<String> element2,
      BiPredicate<String, String> stringStringBiPredicate,
      Consumer<String> u1,
      Consumer<String> u2) {
    String e1 = element1.get();
    String e2 = element2.get();
    if (stringStringBiPredicate.test(e1, e2)) {
      e1 = "+" + e1;
      e2 = "-" + e2;      
      u1.accept(e1);
      u2.accept(e2);
    } 
  }
}

希望这会有所帮助！这与 Streams 没有什么不同，而是使用函数式方法而不是您的声明式方法来解决问题。这也可以用 Normal 循环而不是 IntStream 来编写。

PS：就性能而言，这可能比声明式实现还要慢，因为它涉及多个方法调用。但是，与代码可维护性相比，节省一些纳秒并不是一个好的权衡。