是否可以扩展已经存在的类以引发异常?例如,如果条目已经存在,是否可以为以下代码创建异常?(我无法修改类,因此我需要扩展并且必须包含错误处理,而不仅仅是显示消息..)
入职类:
public Entry(String paramString1, String paramString2, String paramString3, String paramString4, String paramString5)
{
this.firstName = paramString1;
this.lastName = paramString2;
this.street = paramString3;
this.town = paramString4;
if (paramString5.matches("[A-Z]{2}[0-9]{1,2} [0-9]{1,2}[A-Z]{2}")) {
this.postCode = paramString5;
} else {
System.err.printf("Bad postcode: '%s'\n", new Object[] { paramString5 });
this.postCode = "???";
}
}
地址簿类:
public String add(Entry paramEntry)
{
if (paramEntry == null)
return "Error: null entry";
if (this.data.contains(paramEntry)) {
return "Error: this entry already in the book";
}
boolean bool = this.data.add(paramEntry);
if (bool) {
return " entry added";
}
return "entry could not be added";
}
我搜索了互联网,发现以下易于遵循的网站: http ://www.tutorialspoint.com/java/java_exceptions.htm http://www.c-sharpcorner.com/UploadFile/433c33/defining-your-own -java中的异常类自定义异常/
这是我需要做的吗?(Java新手对不起)