通用深度比较等于 [英] Generic deep compare equals

问题描述

基本上我不想比较元素，但是包含的元素。

  public boolean equals（Ie< T> that）{
 T This = this.value; 
 T That = that.value; 
 boolean x = That.compareTo（This）== 0; 
 return x; 
} 
  

我所做的是：

  public boolean equals（Object obj）{
 if（obj == null）
 return false; 
 
 String tmp = obj.toString（）; 
 if（this.value instanceof Integer）
 return equalsInt（new Ie< Integer>（Integer.parseInt（tmp）））; 
 //等
 
返回false; 
} 
 
 public boolean equalsInt（Ie< Integer> ie）{
 Integer This = this.value.intValue（）; 
整数那= ie.value; 
 boolean x = That.compareTo（This）== 0; 
 return x; 
} 
  

这是一个明显的蛮力解决方案。是否可以在没有 obj.toString（）; +新元素的情况下完成？

编辑：

Class Ie被定义为：

  public static class Ie< T extends Number&可比< ;? super T>> 
扩展Number implements Comparable< Ie< T>> {
  

类与方法相比相当简单：

  public int compareTo（Ie< T> that）{
 T This = this.value; 
 T That = that.value; 
 return（This.compareTo（That）< 0？-1 :( this 
 .compareTo（That）> 0？1：0））; 
} 
  

我正在使用Collection addall方法中的类，其中contains调用equals。

Erikson解决方案运行良好：

  @Override 
 public boolean equals（Object that）{
 if（that == null）
 return false; 
 if（this == that）
 return true; 
 if（that instanceof Ie<>）{
 Object ThisValue = this.value; 
 Object ThatValue =（（Ie<>）that .value; 
 return ThisValue.equals（ThatValue）; 
} 
 
 return false; 
} 
  

解决方案

  public boolean equals（Object that）
 {
 if（this == that）
 return true; 
 if（that instanceof ie）{
 Object ThisValue = this.value; 
 Object ThatValue =（（Ie<>）that .value; 
 return ThisValue.equals（ThatValue）; 
} else 
返回false; 
} 
  

Basically i don't want to compare elements, but elements that thy contain. It would be cool if following would work, but it does not.

public boolean equals(Ie<T> that) {
    T This = this.value;
    T That = that.value;
    boolean x = That.compareTo(This) == 0;
    return x;
}

What i have done is :

public boolean equals(Object obj) {
    if (obj == null)
        return false;

    String tmp = obj.toString();
    if (this.value instanceof Integer)
        return equalsInt(new Ie<Integer>(Integer.parseInt(tmp)));
    // etc.

    return false;
}

public boolean equalsInt(Ie<Integer> ie) {
    Integer This = this.value.intValue();
    Integer That = ie.value;
    boolean x = That.compareTo(This) == 0;
    return x;
}

This is a obvious brute-force solution. Can it be done without obj.toString(); + new element?

Edit:

Class Ie is defined as:

public static class Ie<T extends Number & Comparable<? super T>>
        extends Number implements Comparable<Ie<T>> {

Class has rather simple compare to method:

public int compareTo(Ie<T> that) {
    T This = this.value;
    T That = that.value;
    return (This.compareTo(That) < 0 ? -1 : (This
            .compareTo(That) > 0 ? 1 : 0));
}

I am using the class in Collection addall method, where contains is calling equals.

Erikson solution worked fine:

@Override
public boolean equals(Object that) {
    if (that == null)
        return false;
    if (this == that)
        return true;
    if (that instanceof Ie<?>) {
        Object ThisValue = this.value;
        Object ThatValue = ((Ie<?>) that).value;
        return ThisValue.equals(ThatValue);
    }

    return false;
}

解决方案

@Override
public boolean equals(Object that)
{
    if (this == that)
      return true;
    if (that instanceof Ie) {
      Object ThisValue = this.value;
      Object ThatValue = ((Ie<?>) that).value;
      return ThisValue.equals(ThatValue);
    } else 
      return false;
}

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