blocks|key|160919|text|在Java8中，除了默认方法之外，还可以在接口中定义静态方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|160920|160921|静态方法是与定义它的类相关联的方法，而不是与任何对象相关联的方法。该类的每个实例都共享其静态方法。|unordered-list-item|160922|这使您可以更轻松地在库中组织帮助器方法；您可以将特定于接口的静态方法保留在同一接口中，而不是放在单独的类中。|160923|下面的示例定义了一个静态方法，该方法检索与时区标识符对应的ZoneId对象；如果没有与给定标识符对应的ZoneId对象，则使用系统默认时区。(因此，您可以简化方法getZonedDateTime)|CODE|160924|160925|下面是代码：|160926|public+interface+TimeClient+{
+++//+...
++++static+public+ZoneId+getZoneId+(String+zoneString)+{
++++++++try+{
++++++++++++return+ZoneId.of(zoneString);
++++++++}+catch+(DateTimeException+e)+{
++++++++++++System.err.println("Invalid+time+zone:+"+%2B+zoneString+%2B";+using+default+time+zone+instead.");
++++++++++++return+ZoneId.systemDefault();
++++++++}
++++}

+++default+public+ZonedDateTime+getZonedDateTime(String+zoneString)+{
++++++return+ZonedDateTime.of(getLocalDateTime(),+getZoneId(zoneString));
+++}++++
}|code-block|syntax|javascript|160927|另请参阅|160928|在Java8中阅读|160929|Oracle+docs+for+interface+methods|160930|For所有有趣的东西Everything+about+Java+8|160931|160932|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html|1|http://www.techempower.com/blog/2013/03/26/everything-about-java-8/^0|1|5|0|0|0|0|T|6|1F|6|29|G|0|0|0|0|0|0|0|X|0|0|A|N|1|0|0^^$0|@$1|2|3|4|5|6|7|1F|8|@$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|1I|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|1J|8|@]|D|@]|E|$]]|$1|J|3|K|5|I|7|1K|8|@]|D|@]|E|$]]|$1|L|3|M|5|I|7|1L|8|@$9|1M|A|1N|B|N]|$9|1O|A|1P|B|N]|$9|1Q|A|1R|B|N]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1S|8|@]|D|@]|E|$]]|$1|P|3|Q|5|6|7|1T|8|@]|D|@]|E|$]]|$1|R|3|S|5|T|7|1U|8|@]|D|@]|E|$U|V]]|$1|W|3|X|5|6|7|1V|8|@]|D|@]|E|$]]|$1|Y|3|Z|5|6|7|1W|8|@]|D|@]|E|$]]|$1|10|3|11|5|I|7|1X|8|@]|D|@$9|1Y|A|1Z|1|20]]|E|$]]|$1|12|3|13|5|I|7|21|8|@]|D|@$9|22|A|23|1|24]]|E|$]]|$1|14|3|-4|5|6|7|25|8|@]|D|@]|E|$]]|$1|15|3|-4|5|6|7|26|8|@]|D|@]|E|$]]]|16|$17|$5|18|19|1A|E|$1B|1C]]|1D|$5|18|19|1A|E|$1B|1E]]]]

From Java 8 you can define static methods in interfaces in addition to default methods. 

<ul>
<li>A static method is a method that is associated with the class in which it is defined rather than with any object. Every instance of the class shares its static methods.</li>
<li>This makes it easier for you to organize helper methods in your libraries; you can keep static methods specific to an interface in the same interface rather than in a separate class.</li>
<li>The following example defines a static method that retrieves a <code>ZoneId</code> object corresponding to a time zone identifier; it uses the system default time zone if there is no <code>ZoneId</code> object corresponding to the given identifier. (As a result, you can simplify the method <code>getZonedDateTime</code>)</li>
</ul>

Here is code :

<pre><code>public interface TimeClient {
 // ...
 static public ZoneId getZoneId (String zoneString) {
 try {
 return ZoneId.of(zoneString);
 } catch (DateTimeException e) {
 System.err.println("Invalid time zone: " + zoneString +"; using default time zone instead.");
 return ZoneId.systemDefault();
 }
 }

 default public ZonedDateTime getZonedDateTime(String zoneString) {
 return ZonedDateTime.of(getLocalDateTime(), getZoneId(zoneString));
 } 
}
</code></pre>

<h2>See also</h2>

<ul>
<li><a href="http://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html">Oracle docs for interface methods</a></li>
<li>For all interesting things in Java 8 read <a href="http://www.techempower.com/blog/2013/03/26/everything-about-java-8/">Everything about Java 8</a></li>
</ul>

blocks|key|2748728|text|这只在Java8中是可能的。在Java++Language+Specification+§9.4中，它明确地声明：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2748729|2748730|如果在接口中声明的方法被声明为静态，则它是编译时错误，因为静态方法不能是抽象的。|blockquote|2748731|2748732|2748733|因此，在Java7中，接口中的静态方法不能存在。|2748734|如果你去Java++Language+Specification+§9.4.3，你可以看到它说：|2748735|2748736|静态方法也有一个块体，它提供方法的实现。|2748737|2748738|2748739|所以它明确指出，在Java+8中，它们可以存在。|2748740|我甚至试着用Java语言运行你的1.7.0_45代码，但是它给了我一个错误：“这里不允许修饰符静态”。|2748741|2748742|下面是对JavaJava8教程Default+Methods+(Learning+the+Java+Language+>+Interfaces+and+Inheritance)的直接引用|2748743|2748744|静态方法|2748745|2748746|除了默认方法之外，您还可以在接口中定义static+methods。(静态方法是与定义它的类相关联的方法，而不是与任何对象相关联的方法。该类的每个实例都共享其静态方法。)这使您可以更容易地在库中组织帮助器方法；您可以将特定于接口的静态方法保留在同一接口中，而不是放在单独的类中。下面的示例定义了一个静态方法，该方法检索与时区标识符对应的ZoneId对象；如果没有与给定标识符对应的ZoneId对象，则使用系统默认时区。(因此，您可以简化方法getZonedDateTime)：|style|CODE|2748747|公共接口TimeClient+{+//+...静态公共ZoneId+getZoneId+(String+zoneString)+{+try+{+return+ZoneId.of(+zoneString+)；}+catch+(DateTimeException+e)+{System.err.println(“无效时区：”%2BzoneString%2B+"；改为使用默认时区。“)；return+ZoneId.systemDefault()；}}默认公网ZonedDateTime+getZonedDateTime(String+zoneString)+{+return+ZonedDateTime.of(getLocalDateTime()，getZoneId(zoneString))；}}|2748748|与类中的静态方法类似，您可以指定接口中的方法定义是在方法签名的开头带有static关键字的静态方法。接口中的所有方法声明(包括静态方法)都是隐式的public，因此可以省略public修饰符。|2748749|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/specs/jls/se7/html/jls-9.html#jls-9.4|1|http://docs.oracle.com/javase/specs/jls/se8/html/jls-9.html#jls-9.4.3|2|http://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html#static|3|http://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html|4|http://docs.oracle.com/javase/8/docs/api/java/time/ZoneId.html^0|F|X|0|0|0|0|0|0|0|4|Z|1|0|0|0|0|0|0|0|0|F|21|2|0|0|0|0|4O|6|5A|6|64|G|J|E|3|4O|6|4|0|0|Z|6|21|6|2E|6|0^^$0|@$1|2|3|4|5|6|7|1R|8|@]|9|@$A|1S|B|1T|1|1U]]|C|$]]|$1|D|3|-4|5|6|7|1V|8|@]|9|@]|C|$]]|$1|E|3|F|5|G|7|1W|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|1X|8|@]|9|@]|C|$]]|$1|I|3|-4|5|6|7|1Y|8|@]|9|@]|C|$]]|$1|J|3|K|5|6|7|1Z|8|@]|9|@]|C|$]]|$1|L|3|M|5|6|7|20|8|@]|9|@$A|21|B|22|1|23]]|C|$]]|$1|N|3|-4|5|6|7|24|8|@]|9|@]|C|$]]|$1|O|3|P|5|G|7|25|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|26|8|@]|9|@]|C|$]]|$1|R|3|-4|5|6|7|27|8|@]|9|@]|C|$]]|$1|S|3|T|5|6|7|28|8|@]|9|@]|C|$]]|$1|U|3|V|5|6|7|29|8|@]|9|@]|C|$]]|$1|W|3|-4|5|6|7|2A|8|@]|9|@]|C|$]]|$1|X|3|Y|5|6|7|2B|8|@]|9|@$A|2C|B|2D|1|2E]]|C|$]]|$1|Z|3|-4|5|6|7|2F|8|@]|9|@]|C|$]]|$1|10|3|11|5|G|7|2G|8|@]|9|@]|C|$]]|$1|12|3|-4|5|6|7|2H|8|@]|9|@]|C|$]]|$1|13|3|14|5|6|7|2I|8|@$A|2J|B|2K|15|16]|$A|2L|B|2M|15|16]|$A|2N|B|2O|15|16]]|9|@$A|2P|B|2Q|1|2R]|$A|2S|B|2T|1|2U]]|C|$]]|$1|17|3|18|5|6|7|2V|8|@]|9|@]|C|$]]|$1|19|3|1A|5|6|7|2W|8|@$A|2X|B|2Y|15|16]|$A|2Z|B|30|15|16]|$A|31|B|32|15|16]]|9|@]|C|$]]|$1|1B|3|-4|5|6|7|33|8|@]|9|@]|C|$]]]|1C|$1D|$5|1E|1F|1G|C|$1H|1I]]|1J|$5|1E|1F|1G|C|$1H|1K]]|1L|$5|1E|1F|1G|C|$1H|1M]]|1N|$5|1E|1F|1G|C|$1H|1O]]|1P|$5|1E|1F|1G|C|$1H|1Q]]]]

This is only possible in Java 8. In the <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-9.html#jls-9.4" rel="noreferrer">Java 7 Language Specification §9.4</a>, it explicitly states:

<blockquote>
 It is a compile-time error if a method declared in an interface is declared static, because static methods cannot be abstract.
</blockquote>

So in Java 7, static methods in interfaces cannot exist.

If you go to the <a href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-9.html#jls-9.4.3" rel="noreferrer">Java 8 Language Specification §9.4.3</a>, you can see that it says:

<blockquote>
 A static method also has a block body, which provides the implementation of the method.
</blockquote>

So it explicitly states that in Java 8, they can exist.

I even tried to run your exact code in Java 1.7.0_45, but it gave me the error "modifier static not allowed here".

<hr>

Here is a quote directly from the Java 8 tutorial, <a href="http://docs.oracle.com/javase/tutorial/java/IandI/defaultmethods.html#static" rel="noreferrer">Default Methods (Learning the Java Language > Interfaces and Inheritance)</a>:

<blockquote>
 <h2>Static Methods</h2>
 
 In addition to default methods, you can define <a href="http://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html" rel="noreferrer">static methods</a> in
 interfaces. (A static method is a method that is associated with the
 class in which it is defined rather than with any object. Every
 instance of the class shares its static methods.) This makes it easier
 for you to organize helper methods in your libraries; you can keep
 static methods specific to an interface in the same interface rather
 than in a separate class. The following example defines a static
 method that retrieves a <a href="http://docs.oracle.com/javase/8/docs/api/java/time/ZoneId.html" rel="noreferrer"><code>ZoneId</code></a> object corresponding to a time
 zone identifier; it uses the system default time zone if there is no
 <code>ZoneId</code> object corresponding to the given identifier. (As a result,
 you can simplify the method <code>getZonedDateTime</code>):

<pre><code>public interface TimeClient {
 // ...
 static public ZoneId getZoneId (String zoneString) {
 try {
 return ZoneId.of(zoneString);
 } catch (DateTimeException e) {
 System.err.println("Invalid time zone: " + zoneString +
 "; using default time zone instead.");
 return ZoneId.systemDefault();
 }
 }

 default public ZonedDateTime getZonedDateTime(String zoneString) {
 return ZonedDateTime.of(getLocalDateTime(), getZoneId(zoneString));
 } 
}
</code></pre>
 
 Like static methods in classes, you specify that a method definition
 in an interface is a static method with the <code>static</code> keyword at the
 beginning of the method signature. All method declarations in an
 interface, including static methods, are implicitly <code>public</code>, so you
 can omit the <code>public</code> modifier.
</blockquote>

blocks|key|158496|text|对于java版本7或更低版本的，您可以使用在接口体中声明的嵌套类来实现类似的功能。这个嵌套类实现了外部接口。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|158497|示例：|158498|interface+I1{
++++public+void+doSmth();

++++class+DefaultRealizationClass+implements++I1{

++++++++@Override
++++++++public+void+doSmth()+{
+++++++++++System.out.println("default+realization");
++++++++}
++++}
}|code-block|syntax|javascript|158499|我们如何在我们的代码中使用它？|158500|class+MyClass+implements+I1{

++++@Override
++++public+void+doSmth()+{
+++++++++new+I1.DefaultRealizationClass().doSmth();
++++}+++
}|158501|因此，默认实现封装在接口中。|158502|entityMap^0|2|4|8|7|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|11|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|13|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

For java version 7 or below, similar functionally you can achieve using nested class declared within interface body. and this nested class implements outer interface.

<h2>Example:</h2>

<pre><code>interface I1{
 public void doSmth();

 class DefaultRealizationClass implements I1{

 @Override
 public void doSmth() {
 System.out.println("default realization");
 }
 }
}
</code></pre>

<h2>How do we use it in our code?</h2>

<pre><code>class MyClass implements I1{

 @Override
 public void doSmth() {
 new I1.DefaultRealizationClass().doSmth();
 } 
}
</code></pre>

Therefore default implementation encapsulated within interface.

I know that an interface is like a 100% pure abstract class. So, it can't have method implementation in it. But, I saw a strange code. Can anyone explain it?

Code Snippet:

<pre><code> interface Whoa {
 public static void doStuff() {
 System.out.println("This is not default implementation");
 }
 }
</code></pre>

EDIT:

My IDE is Intellij Idea 13.1. The project SDK is java 7 &lt;1.7.0_25>. The IDE is not showing any compiler error. But, When I compile the code at command line I am getting the following message. 

<blockquote>
<pre><code>Whoa.java:2: error: modifier static not allowed here
 public static void doStuff() {
 ^
</code></pre>
</blockquote>

Can an interface method have a body?

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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我知道接口就像一个100%纯抽象的类。因此，它不能在其中包含方法实现。但是，我看到了一个奇怪的代码。有人能解释一下吗？代码片段： interface Whoa {        public static void doStuff() {            System.out.println("This is n...

问接口方法可以有主体吗？
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问接口方法可以有主体吗？
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