抛出和抓获异常

抛出异常 抓获异常
异常处理的五个关键字：
try 、catch、finally、throw、throws
System.out.println("000000000000000000000000000000000000000000000000000000000000000000000000000000");
public class Demo01 {
public static void main(String[] args) {
int a=1;
int b=0;
//假设要捕获多个异常，从小到大！
try{//try监控区域
System.out.println(a/b);
}catch(Error e){//catch(想要捕获的异常类型！)捕获异常
System.out.println("Error");
}catch(Exception e){
System.out.println("Exception");
}catch(Throwable e){
System.out.println("Throwable");
}finally{//处理善后工作
System.out.println("finally");
}
//finally 可以不要finally，假设IO，资源，关闭
}
public void a(){
b();
}
public void b(){
a();
}
}
System.out.println("000000000000000000000000000000000000000000000000000000000000000000000000000000");
运行结果：
Exception
finally
System.out.println("000000000000000000000000000000000000000000000000000000000000000000000000000000");
public class Test {
public static void main(String[] args) {
try{
new Test().test(1,0);
}catch(ArithmeticException e){
e.printStackTrace();
}
}
//假设这个方法中，处理不了这个异常，方法上抛出异常
public void test(int a,int b) throws ArithmeticException{
if(b==0){
throw new ArithmeticException();//主动的抛出异常，一般在方法中使用
}
}
}
运行结果：
at Test.test(Test.java:12)
at Test.main(Test.java:4)