public class NullPointerException
extends RuntimeException
| java.lang.Object | ||||
| ↳ | java.lang.Throwable | |||
| ↳ | java.lang.Exception | |||
| ↳ | java.lang.RuntimeException | |||
| ↳ | java.lang.NullPointerException | |||
当应用程序尝试在需要对象的情况下使用null时抛出。 这些包括：
Android开发手册null object. null object. null as if it were an array. null as if it were an array. null as if it were a Throwable value. 应用程序应该抛出此类的实例来指示null对象的其他非法使用。 NullPointerException对象可以由虚拟机构造，就像suppression were disabled and/or the stack trace was not writable一样 。
Public constructors |
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|---|---|
NullPointerException() 构造一个没有详细信息的 |
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NullPointerException(String s) 用指定的详细信息构造一个 |
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Inherited methods |
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|---|---|
 From class java.lang.Throwable
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From class java.lang.Object
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NullPointerException ()
构造一个没有详细信息的 NullPointerException 。
NullPointerException (String s)
用指定的详细信息构造一个 NullPointerException 。
| Parameters | |
|---|---|
s |
String: the detail message. |