Java – provides multiple types of sorting for objects

Suppose I have a Java object with multiple string fields

public class Person {
    private String field1
    // keeps going

I want to be able to sort the list of people according to any field I choose

I know that I can use the comparator interface and implement multiple comparetos, such as the topic: how do I make 2 comparable methods in only one class? As described in

But when using collections When sort()

But without all this repetitive code, is there any way I can do this?

Solution

@JB nizet's Java 8 solution will be a trick, but it only applies to Java 8 What is the version below 8 that most people use?

I will provide you with a simple solution that I think is lower than Java 8

You really don't need to create multiple comparator classes (you call them "duplicate code") How to use appropriate techniques, such as conditions or enumerations?

private Comparator<YourClass> getComparator(MyPropertiesEnum myEnum) {
   return new Comparator<YourClass>() {

      @Override
      public int compare(YourClass o1,YourClass o2) { {
         switch (myEnum) {
            case FIRSTNAME:
               // implementation for firstname
            break;
            case LASTNAME:
              // implementation for lastname
            break;
            default:
               // implementation for default version
            break;           
         }
      }
   };
}

The location of mypropertiesenum is as follows:

public enum MyPropertiesEnum {
   FIRSTNAME,LASTNAME,AGE;
}

Note: if the conditions are suitable for you, you can also use the appropriate conditions

I hope it can help you solve the problem