import java.io.IOException; import java.sql.SQLException; //java异常处理 //异常 public class test82 { //定义方法声明定义异常,在满足条件时抛出异常对象,程序转向异常处理 public double count(double n, double m, Connection conn)throws ArithmeticException,SQLException { if (m == 0) {//如果除数等于0.则抛出异常实例 throw new ArithmeticException("对不起。除数不能等于0"); } if(conn==null||conn.isClosed()){ throw new SQLException( "数据库连接失败" ); } return n/m; } }测试类 import java.io.IOException; import java.sql.Connection; import java.sql.SQLException; import java.util.Collection; public class test83 { public static void main(String[] args){ test82 com1=new test82(); Collection conn=null; try { double t = com1.count( 78, 2, (Connection) conn ); }catch (ArithmeticException| SQLException e){ System.out.println( e.getClass().getName()); e.printStackTrace(); } } }