用IntelliJ IDEA生成的equals和hashCode方法

JavaBeanEqualsBaseOnNotNullFields.java

 @Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    UpdateConfig that = (UpdateConfig) o;

    if (!fromVersion.equals(that.fromVersion)) return false;
    if (!targetVersion.equals(that.targetVersion)) return false;

    return true;
}

@Override
public int hashCode() {
    int result = targetVersion.hashCode();
    result = 31 * result + fromVersion.hashCode();
    return result;
}

JavaBeanEqualsBaseOnNullFields.java

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    UpdateConfig that = (UpdateConfig) o;

    if (fromVersion != null ? !fromVersion.equals(that.fromVersion) : that.fromVersion != null) return false;
    if (targetVersion != null ? !targetVersion.equals(that.targetVersion) : that.targetVersion != null)
        return false;

    return true;
}

@Override
public int hashCode() {
    int result = targetVersion != null ? targetVersion.hashCode() : 0;
    result = 31 * result + (fromVersion != null ? fromVersion.hashCode() : 0);
    return result;
}