从equals（）调用hashCode（）(Calling hashCode() from equals())

 我已经为我的类定义了hashCode() ，并使用了很长的类属性列表。 
 
 根据契约，我还需要实现equals（），但是可以通过简单地通过比较里面的hashCode()来实现它，以避免所有额外的代码？ 这样做有什么危险吗？ 
 
 例如 
 
@Override
public int hashCode() 
{
    return new HashCodeBuilder(17, 37)
        .append(field1)
        .append(field2)
    // etc.
    // ...
}

@Override
public boolean equals(Object that) {
    // Quick special cases
    if (that == null) {
        return false;
    }
    if (this == that) {
        return true;
    }
    // Now consider all main cases via hashCode()
    return (this.hashCode() == that.hashCode());
}

I have defined hashCode() for my class, with a lengthy list of class attributes.
 
Per the contract, I also need to implement equals(), but is it possible to implement it simply by comparing hashCode() inside, to avoid all the extra code? Are there any dangers of doing so?
 
e.g.
 
@Override
public int hashCode() 
{
    return new HashCodeBuilder(17, 37)
        .append(field1)
        .append(field2)
    // etc.
    // ...
}

@Override
public boolean equals(Object that) {
    // Quick special cases
    if (that == null) {
        return false;
    }
    if (this == that) {
        return true;
    }
    // Now consider all main cases via hashCode()
    return (this.hashCode() == that.hashCode());
}

原文：https://stackoverflow.com/questions/29903291