Question

当我在私有字段中使用@Canonical批注时，我不断收到“找不到匹配的构造函数”。我可以知道如何获得以下代码来编译并传递断言吗？谢谢:)）

@groovy.transform.Canonical(includes = ['x','y'])
@groovy.transform.EqualsAndHashCode(includeFields = true)
class Cell implements Comparable<Cell>{
    private int x
    private int y

    int compareTo(Cell cell){
        x <=> cell.x ?: y <=> cell.y ?: 0
    }
}

Cell cell = new Cell(1,0);
Cell sameCell = new Cell(1,0);
def setOfLiveCells = [] as Set

assert setOfLiveCells.add(cell) // cell is added
assert cell == sameCell // cell equals
assert ! setOfLiveCells.add(sameCell) //should not assert

此致约翰

Answer 1

是的，你可以这样做。

@Canonical是带有默认值的@TupleConstructor @ToString和@EqualsAndHashCode注释的简写。 [code]您可以手动指定它们，或者只需在 Canonical之前添加必要的注释。 @TupleConstructor允许您通过includeFields或include注释字段设置字段。 [doc]

@groovy.transform.TupleConstructor(includeFields = true) @groovy.transform.Canonical class Cell implements Comparable<Cell>{ private int x private int y int compareTo(Cell cell){ x <=> cell.x ?: y <=> cell.y ?: 0 } } Cell cell = new Cell(1,0); Cell sameCell = new Cell(1,0); def setOfLiveCells = [] as Set assert setOfLiveCells.add(cell) // cell is added assert cell == sameCell // cell equals assert ! setOfLiveCells.add(sameCell) //should not assert

Groovy @Canonical是否与私有领域合作？

1 个答案: