blocks|key|2918257|text|您只需要实现接口中尚未在抽象类中实现的方法，抽象类是您尝试实现方法的类的超类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2918258|但看来我在你的考试课上看到了一个问题。|2918259|您的接口声明了此方法，|2918260|Double+salary();|code-block|syntax|javascript|2918261|在check类中实现此方法时，|2918262|public+double+sal()|2918263|因此，这实际上并不是从接口实现方法。您需要使它与它在界面上相同。|2918264|就像这样在你的检查类中创建一个方法，|2918265|public+Double+salary()
++++{
++++++++return+25000.00;
++++}|2918266|在实现/重写超类/接口中的方法时，您应该始终使用@重写注释，以便在任何方法签名不同的情况下，它将提示您在那里出错。是的，如果在子类检查中再次声明name()方法，它将覆盖抽象class.You中的方法，在类中可以这样做，|2918267|abstract+class+GetNames+implements+xxx
{
++++@Override
++++public+String+names()
++++{
++++++++return+"Ravi";
++++}
}

class+Check+extends+GetNames
{
++++@Override
++++public+int+numbers()
++++{
++++++++return+3;
++++}
++++public+double+sal()
++++{
++++++++return+25000.00;
++++}
++++@Override
++++public+Double+salary()+{
++++++++return+sal();
++++}

++++@Override
++++public+String+names()+{+//+this+overrides+names()+method+in+GetNames+class
++++++++return+"Check";
++++}


}|2918268|entityMap^0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|12|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|13|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|14|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|15|8|@]|9|@]|A|$I|J]]|$1|O|3|P|5|6|7|16|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|17|8|@]|9|@]|A|$]]|$1|S|3|T|5|H|7|18|8|@]|9|@]|A|$I|J]]|$1|U|3|V|5|6|7|19|8|@]|9|@]|A|$]]|$1|W|3|X|5|H|7|1A|8|@]|9|@]|A|$I|J]]|$1|Y|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|Z|$]]

You only need to implement methods from Interface which have not been implemented in abstract class which is a super class for your class where you are trying to implement methods.

But looks like I see one problem in your Check class.

Your interface declares this method,

<pre><code>Double salary();
</code></pre>

Where as in check class you are implementing this method,

<pre><code>public double sal()
</code></pre>

So this really doesn't implement a method from interface. You need to make it same as it is in interface.

Just make method in your Check class like this,

<pre><code>public Double salary()
 {
 return 25000.00;
 }
</code></pre>

While implementing/overriding a method from superclass/interface, you should always use @Override annotation so in case any of your method signature differs, it will prompt you for error right there. And yes if you declare names() method again in your subclass Check, it will override the one in abstract class.You can do something like this in your class,

<pre><code>abstract class GetNames implements xxx
{
 @Override
 public String names()
 {
 return "Ravi";
 }
}

class Check extends GetNames
{
 @Override
 public int numbers()
 {
 return 3;
 }
 public double sal()
 {
 return 25000.00;
 }
 @Override
 public Double salary() {
 return sal();
 }

 @Override
 public String names() { // this overrides names() method in GetNames class
 return "Check";
 }


}
</code></pre>

blocks|key|1278281|text|扩展abstract类的具体类必须为超类中的所有抽象方法提供主体。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1278282|除非提供默认主体，否则接口中的方法默认为-+abstract。|1278283|当抽象类实现接口时，接口的所有方法都继承为抽象。|1278284|现在，在您的场景中，您已经为接口的继承方法之一提供了一个主体，该方法在“抽象”类的范围内不再是抽象的。因此，如果一个类扩展了这个抽象类，那么它就不需要为上面的方法提供一个主体，因为它不再是抽象的(当然，他们可以重写它)。|1278285|您在Check子类中得到了一个错误，它是您为不继承salary()方法而定义的，而不是您已经在GetNames抽象类中定义的names()方法。|1278286|entityMap^0|2|8|0|M|8|0|0|0|2|5|P|8|1B|8|1Q|7|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|W|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|O|$]]

A concrete class extending an <code>abstract</code> class must provide body to all the abstract method in super class. 

Methods in an interface are by default- <code>abstract</code> unless you provide a default body.

When an abstract class implements an interface, all those methods of an interface are inherited as it is i.e. abstract

Now for your scenario, where you have provided a body for one of the inherited method of the interface, this method is no longer abstract in the scope of 'Abstract' class. So, if a class extends this abstract class, then it need not provide a body for the above method because it is no longer abstract(They can of-course override it).

You are getting an error in <code>Check</code> subclass that you have defined for not inheriting <code>salary()</code> method, not <code>names()</code> method that you have already defined in <code>GetNames</code> abstract class

blocks|key|988194|text|您的GetNames类正在实现xxx接口，但是您只实现了name()，您必须实现工资方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|988195|interface+xxx
{
+++++int+numbers();
+++++String+names();
+++++Double+salary();
}
abstract+class+GetNames+implements+xxx
{
++++public+String+names()
++++{
++++++++return+"Ravi";
++++}
++++public+Double+salary()
++++{
++++++++return+null;//just+return+null;
++++}
}
class+Check+extends+GetNames
{
++++public+int+numbers()
++++{
++++++++return+3;
++++}
++++public+double+sal()
++++{
++++++++return+25000.00;
++++}
}|code-block|syntax|javascript|988196|或者直接扔NotImplementedException；|988197|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

your GetNames class is implementing xxx interface but you are only implementing names() 
you must implement salary method.

<pre><code>interface xxx
{
 int numbers();
 String names();
 Double salary();
}
abstract class GetNames implements xxx
{
 public String names()
 {
 return "Ravi";
 }
 public Double salary()
 {
 return null;//just return null;
 }
}
class Check extends GetNames
{
 public int numbers()
 {
 return 3;
 }
 public double sal()
 {
 return 25000.00;
 }
}
</code></pre>

or just throw NotImplementedException;

I am trying to extends an abstract class which is implemented one method of interface so in my subclass i am trying to implement rest of the methods declared in interface but sub class forcing me to declare all the methods of interface, please help me to fix this, thanks in advance i have added my code below. Thanks much in advance seniors.

My code

<pre><code> interface xxx
 {
 int numbers();
 String names();
 Double salary();
 }
 abstract class GetNames implements xxx
 {
 public String names()
 {
 return "Ravi";
 }
 }
 class Check extends GetNames
//This class forcing me to implement names also
 {
 public int numbers()
 {
 return 3;
 }
 public double sal()
 {
 return 25000.00;
 }
 }

 public class AbsUsingInterface {

 }
</code></pre>

Do i need to implement all the methods of interface again while inheriting abstract class in Java?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我试图扩展一个抽象类，它实现了一个接口方法，因此在我的子类中，我试图实现接口中声明的其余方法，但子类迫使我声明所有接口方法，请帮助我修复这个问题，谢谢我在下面添加了我的代码。谢谢大四的人。我的代码   interface xxx    {         int numbers();         String na...

问在Java中继承抽象类时，是否需要再次实现所有接口方法？
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