public static void main(String[] args) {try {System.out.println("Hello world");} catch(IOException e) {System.out.println("抓到一个IO 异常!");}}

It is a compile-time error if a method or constructor body can throw some exception class E when E is a checked exception class and E is not a subclass of some class declared in the throws clause of the method or constructor.It is a compile-time error if a lambda body can throw some exception class E when E is a checked exception class and E is not a subclass of some class declared in the throws clause of the function type targeted by the lambda expression.It is a compile-time error if a class variable initializer (§8.3.2) or static initializer (§8.7) of a named class or interface can throw a checked exception class.It is a compile-time error if an instance variable initializer (§8.3.2) or instance initializer (§8.6) of a named class can throw a checked exception class,
unless the named class has at least one explicitly declared constructor and the exception class or one of its superclasses is explicitly declared in the throws clause of each constructor.It is a compile-time error if a catch clause can catch checked exception class E1 and it is not the case that the try block corresponding to the catch clause can throw a checked exception class that is a subclass or superclass of E1,
unless E1 is Exception or a superclass of Exception.It is a compile-time error if a catch clause can catch an exception class E1 and a preceding catch clause of the immediately enclosing try statement can catch E1 or a superclass of E1.

import java.io.IOException;
public class TryCatchException {public static void main(String[] args) {try {System.out.println("Hello world");throw new IOException();//或者子异常，如throw new FileNotFoundException();} catch(IOException e) {System.out.println("抓到一个IO 异常!");}}
}

public class TryCatchException {public static void main(String[] args) {try {System.out.println("hello world!");} catch(Exception e) {System.out.println("捕获到异常");}}
}

public interface FileNotFound {void run() throws FileNotFoundException;
}public interface CloneNotSupported {void run() throws CloneNotSupportedException;
}public class TryCatchException implements FileNotFound,CloneNotSupported {public static void main(String[] args) {TryCatchException e=new TryCatchException();e.run();}@Overridepublic void run() {System.out.println("Hello world");        }
}