package j2se;
import java.util.Scanner;
public class DM002 {
public static void main(String[] args) {
DT d=new DT();
try{//这里去处理,这里不想处理，就在主函数上边第5行再往上抛，抛给jre
d.qq();
}
catch(Exception e){
System.out.println("输入有误");
}
finally{
System.out.println("程序继续运行中");
}
}
}
class DT{
Scanner in=new Scanner(System.in);
public void qq() throws Exception{//抛给调用这个方法的地方去处理，向上抛
int a=in.nextInt();
int b=in.nextInt();
int c=a%b;
System.out.println("余数为"+c);
}
}
======
package j2se;
import java.util.*;
class DM{
Scanner in=new Scanner(System.in);
public void qy(){
try{
int a=in.nextInt();
int b=in.nextInt();
int c=a%b;
System.out.println("余数为"+c);
}
catch(Exception e){
System.out.println("输入有误");
}
finally{//finally最后一定会执行
System.out.println("程序运行中");
}
}
}
public class DM001 {
public static void main(String[] args) {
DM d=new DM();
d.qy();
}
}
=====手动一个新的异常
package j2se;
public class MyException extends Exception {
public MyException(){
}
public MyException(String message){
super(message);
}
}
==============================
package j2se;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class TestReadFile {
public static void main(String[] args) {
String str=new TestReadFile().openFile();
System.out.println(str);
}
String openFile(){
try{
System.out.println("aaa");
FileInputStream fis=new FileInputStream("d:/a344.txt");
int a=fis.read();
System.out.println("bbb");
return "step1";//先确定返回的值，并不会直接结束运行
}catch(FileNotFoundException e){
System.out.println("catching!!!!!!!");
return "step2";
}catch(IOException e){
e.printStackTrace();
return "step3";
}finally{
System.out.println("finally");
//return "fff";//不要在finally是使用return
}
}
}
try catch finally return 执行顺序
1.先执行try catch ，给返回值赋值
2.执行finally
3.return