<分区>
Possible Duplicate:
Method Overloading for NULL parameter
以下代码编译正常。
public class Main
{
public void temp(Object o)
{
System.out.println("The method with the receiving parameter of type Object has been invoked.");
}
public void temp(String s)
{
System.out.println("The method with the receiving parameter of type String has been invoked.");
}
public void temp(int i)
{
System.out.println("The method with the receiving parameter of type int has been invoked.");
}
public static void main(String[] args)
{
Main main=new Main();
main.temp(null);
}
}
在这段代码中，要调用的方法是接受String类型参数的方法
docs说。
If more than one member method is both accessible and applicable to a method invocation, it is necessary to choose one to provide the descriptor for the run-time method dispatch. The Java programming language uses the rule that the most specific method is chosen.
但我不明白什么时候代码中接受原始int参数的方法之一被修改为接受包装类型Integer的参数比如，
public void temp(Integer i)
{
System.out.println("The method with the receiving parameter of type Integer has been invoked.");
}
发出编译时错误。
reference to temp is ambiguous, both method temp(java.lang.String) in methodoverloadingpkg.Main and method temp(java.lang.Integer) in methodoverloadingpkg.Main match
在这种特殊情况下，为什么用原始数据类型重载方法是合法的，但对于其相应的包装器类型似乎并非如此？