java - Java 中的内联比较器与自定义比较器

Question

对列表进行排序时，使用内嵌 java Comparator(使用匿名内部类)与实现单独的自定义 Comparator 类之间是否存在任何性能差异？

1.

public class SortByErrorComparator implements Comparator<WorkflowError> {
    public int compare(WorkflowError obj1, WorkflowError obj2) {
        return obj1.getErrorCode().compareTo(obj2.getErrorCode());
    }
}
Collections.sort(list, new SortByErrorComparator()) ;

2.

Collections.sort(list, new Comparator<WorkflowError>() {
    public int compare(WorkflowError obj1, WorkflowError obj2) {
        return obj1.getErrorCode().compareTo(obj2.getErrorCode());
    }
});

还有，什么时候调用compare()方法？

Answer 1

还有选项 3 - lambda Function:

Collections.sort(list, (a, b) -> a.getErrorCode().compareTo(b.getErrorCode()));

根据 this benchmark data，这应该快 2 倍左右.

... 或(感谢 @JB Nizet)选项 4:

list.sort(Comparator.comparing(WorkflowError::getErrorCode))