我的问题是上传时错误的捕获异常。我不知道什么是不正确的......
我创建了三个Exception，如下所示：
class A extends Exception{
public void f() throws A{
System.out.println("Exception from A()");
throw new A();
}
public void g() throws A{
System.out.println("Exception from A()");
throw new A();
}
}
class B extends A{
@Override
public void f() throws B{
System.out.println("Exception from B()");
throw new B();
}
}
class C extends B{
@Override
public void f() throws C{
System.out.println("Exception from C()");
throw new C();
}
}
...我希望创建C对象并将此对象强制转换为A并捕获A异常。我的主要看起来像这样：
public static void main(String[] args) {
try {
C obj = new C();
((A)obj).f(); // cast object C --> A.... Why it isn't work ?!
// should catch exception A not C !!!
// problem is when f() method is overrided by subclass
// ((A)obj).g(); // working CORRECT when use other method...
// A obj2 = (A) obj; // I try other casting type
// obj2.g(); //method g() from exception A - work CORRECT, exception A catched...
} catch (C e) { //third in hierarchy
e.printStackTrace(System.err);
} catch (B e) { //second..
e.printStackTrace(System.err);
} catch (A e) { //base
e.printStackTrace(System.err);
}
}
在输出netbeans返回信息：
Exception from C()
exceptions.C
at exceptions.C.f(HierarchyExceptions.java:24)
at exceptions.HierarchyExceptions.main(HierarchyExceptions.java:32)
BUILD SUCCESSFUL (total time: 0 seconds)
我不知道它为什么会返回错误的异常......我尝试评论
//} catch (C e) { //third in hierarchy
// e.printStackTrace(System.err);
//} catch (B e) { //second..
// e.printStackTrace(System.err);
} catch (A e) { //base
e.printStackTrace(System.err);
}
...但它也会返回C异常。
答案 0 :(得分：1)
在课程var secondstack = [];
var positionTop = 20;
var positionLeft = 20;
document.body.style.background = '#00CCFF';
document.body.style.backgroundSize = "cover";
for(var i = 0; i < 25; i++){
var span = document.createElement("span");
span.style.position = "absolute";
span.style.left = positionLeft + "px";
span.style.top = positionTop + "px";
var div = document.createElement("div");
div.style.width = '105px';
div.style.height = '100px';
div.id = i;
div.style.background = '#00FFCC';
$(div).css({backgroundSize: "cover"});
if((positionLeft + 250) < $(window).width()) positionLeft += 120;
else {
old_Width = positionLeft;
var positionTop = 160 + positionTop;
var positionLeft = 20;
}
span.appendChild(div);
document.body.appendChild(span);
}
DivClick();
var resizeTimer;
$(window).resize(function () {
clearTimeout(resizeTimer);
resizeTimer = setTimeout(doSomething, 100);
DivClick()
});
function rearrange(){
$("div").empty();
$("span").empty();
secondstack = [];
var positionTop = 20;
var positionLeft = 20;
for(var i = 0; i < 25; i++){
var span = document.createElement("span");
span.style.position = "absolute";
span.style.left = positionLeft + "px";
span.style.top = positionTop + "px";
var div = document.createElement("div");
div.style.width = '105px';
div.style.height = '100px';
div.id = i;
div.style.background = '#00FFCC';
$(div).css({backgroundSize: "cover"});
if((positionLeft + 250) < $(window).width()) positionLeft += 120;
else {
var positionTop = 160 + positionTop;
var positionLeft = 20;
}
span.appendChild(div);
document.body.appendChild(span);
}
}
function DivClick()
{
$('div').on({click: function(){
var el = document.getElementById(this.id);
el.style.border = "3px solid white";
if(!(secondstack.indexOf(this.id) > -1)) secondstack.push(this.id);
else {
var index = secondstack.indexOf(this.id);
el.style.border = "3px solid black";
secondstack.splice(index, 1);
}
}});
}
和B中，您实际上会覆盖C课程中f()方法的定义。
A此代码将创建类C obj = new C();
((A)obj).f(); // cast object C --> A.... Why it isn't work ?!
// should catch exception A not C !!!
// problem is when f() method is overrided by subclass
的实例，并将其存储到类型为C的局部变量中。一旦调用A方法，它将在真实实例上执行，该实例为f()，而不是C（Java中覆盖规则）。
答案 1 :(得分：0)
这是正确的行为，是否会调用正确的实现：这是$('a.hashLink').on('click', function(e){
e.preventDefault();
var getUrlAfterHash = $(this).attr('href').split('#')[1];
var newURL = getUrlAfterHash +'.html';
window.history.pushState("", "", newURL);
var idPosition = $('#' + getUrlAfterHash).offset();
$('html, body').animate({scrollTop: idPosition.top}, 800);
});
的概念