无法使用eclipse自动生成equals方法

I'm using eclipse to write my Java programs now, but I need to override the equals method so it will take the actual data and not the name or id. When I try to auto-generate it the way I know, it says I have no non-static variables. I added some in and it still doesn't work. I don't know enough about Java to do it myself, but I know enough that I would most likely understand what you are talking about. (I'm not done with my code, I just started. The integers x and y were just to try to make it work.)

我现在正在使用eclipse来编写我的Java程序,但是我需要覆盖equals方法,因此它将获取实际数据,而不是名称或id。当我尝试按照我所知的方式自动生成它时,它说我没有非静态变量。我添加了一些,它仍然无法正常工作。我不太了解Java自己做的事情,但我知道我很有可能理解你在说什么。 (我没有完成我的代码,我刚开始。整数x和y只是为了让它工作。)

package mainPackage;
import java.util.*;

public class Main extends Creater {
    public static void main(String[] args) {
        int x = 0;
        int y = 0;
        thatInput = Inputs.ask();
        Loops.CreateArray();
    }
}

2 个解决方案

#1

The message that you have "no non-static variables" is giving you the right hint. Override the hashCode and equals methods only makes sense if there are non-static variables in the class. So if you changed your example to the following, you could implement those methods (or have them auto-generated for you by eclipse):

您拥有“没有非静态变量”的消息正在为您提供正确的提示。覆盖hashCode和equals方法只有在类中存在非静态变量时才有意义。因此,如果您将示例更改为以下内容,则可以实现这些方法(或者通过eclipse为您自动生成这些方法):

public class Main extends Creater {
    private int x = 0;
    private int y = 0;

    public static void main(String[] args) {
        // other code
    }

    @Override
    public boolean equals(Object obj) {
        // ... your equals code goes here
    }

    @Override
    public int hashCode() {
        // ... your hashCode, er, code goes here
    }

    // ... other code that does wonderful things with x and y
}

Note how I've moved your x and y variables to be at the class level rather than at the method level where you had them. Please also note that someone who or something that creates is a creator, not a creater, that I wouldn't recommend naming your package mainPackage, and that I wouldn't go importing java.util.* in every class just for the sake of it (if you're using eclipse, just do Ctrl + Shift + O to organise your imports).

请注意我是如何将x和y变量移动到类级别而不是在您拥有它们的方法级别。还请注意,创建者或创建者是创建者,而不是创建者,我不建议命名包mainPackage,并且我不会为了每个类而在每个类中导入java.util。*它(如果你正在使用eclipse,只需按Ctrl + Shift + O组织你的导入)。

Please also see which issues to consider when overriding these methods.

还请查看覆盖这些方法时要考虑的问题。

#2

-1

To automatically add equals and hashCode methods:

要自动添加equals和hashCode方法:

Menu -> Source -> Generate hashCode() and equals()

菜单 - >源 - >生成hashCode()和equals()

Select the fields you want make part of hashCode() and equals()

选择你想要成为hashCode()和equals()的一部分的字段

Click Ok

The rest will be done by eclipse.

其余的将由eclipse完成。

#1

public class Main extends Creater {
    private int x = 0;
    private int y = 0;

    public static void main(String[] args) {
        // other code
    }

    @Override
    public boolean equals(Object obj) {
        // ... your equals code goes here
    }

    @Override
    public int hashCode() {
        // ... your hashCode, er, code goes here
    }

    // ... other code that does wonderful things with x and y
}