What are the basic annotations in java

1. java.lang.Override is a tag type annotation, which is used as annotation method. It shows that this method inherits the method of the parent class, that is, it overrides the method of the same name in the parent class.

@Override
public void onCreate(Bundle savedInstanceState)
 
{…….}
这种写法是正确的，如果你写成：
 
@Override
public void oncreate(Bundle savedInstanceState)
{…….}
编译器会报如下错误：The method oncreate(Bundle) of type HelloWorld must override or
implement a supertype method，以确保你正确重写onCreate方法（因为oncreate应该为onCreate）
而如果你不加@Override，则编译器将不会检测出错误，而是会认为你为子类定义了一个新方法：oncreate

2. SuppressWarnings tells the compiler to ignore possible warnings.

There are actually many parameters in it, and different parameters set different warnings.

-  deprecation，使用了过时的类或方法时的警告
-  unchecked，执行了未检查的转换时的警告
-  fallthrough，当 switch 程序块直接通往下一种情况而没有 break 时的警告
-  path，在类路径、源文件路径等中有不存在的路径时的警告
-  serial，当在可序列化的类上缺少serialVersionUID 定义时的警告
-  finally ，任何 finally 子句不能正常完成时的警告
-  all，关于以上所有情况的警告

The above is the detailed content of What are the basic annotations in java. For more information, please follow other related articles on the PHP Chinese website!