赣90J601 围墙大门图集.pdf

异常处理
Java异常处理的基础知识
错误与异常
异常处理机制

异常类的产生、捕获与处理
异常的分类
抛出异常
自定义异常类
异常类的产生、捕获与处理

-catch-finally语句捕获与处理异常
3. Exception异常类的方法
public class Try1
{
public static void main (String args[])
{
int i=0;
int a[] = {5,6,7,8};
for(i=0;i<5;i++)
(" a["+i+"]="+a[i]);
("3/0="+(3/0));
}
}
ArrayIndexOutOfBoundsException
D:\myjava>javac
D:\myjava>java Try1
a[0]=5
a[1]=6
a[2]=7
a[3]=8
Exception in thread "main"
at (:8)
D:\myjava>javac
D:\myjava>java Try1
Exception in thread "main" : / by zero
at (:9)
使用try-catch-finally语句捕获与处理异常
try
{
<语句1>
}
catch(ExceptionType e)
{
<语句2>
}
finally
{
<语句3>
}
public class Try2
{ public static void main (String args[])
{ int i=0;
int a[] = {5,6,7,8};
for(i=0;i<5;i++)
{ try
{ ("a["+i+"]/"+i+"="+(a[i]/i));
}
catch(ArrayIndexOutOfBoundsException e)
{ ("捕获数组下标越界异常!");
}
catch(ArithmeticException e)
{("捕获算术异常!");
}
catch(Exception e)
{ ("捕获"+()+"异常!");
} //显示异常信息
finally
{ (" finally i="+i);
}
}
("继续!");
}
}
捕获算术异常! finally i=0
a[1]/1=6 finally i=1
a[2]/2=3 finally i=2
a[3]/3=2 finally i=3
捕获数组下标越界异常! finally i=4
继续!
public class Try2
{ public static void main (String args[])
{ int i=0;
int a[] = {5,6,7,8};
for(i=0;i<5;i++)
{ try
{ ("a["+i+"]/"+i+"="+(a[i]/i));
}
/*catch(ArrayIndexOutOfBoundsException e)
{ ("捕获数组下标越界异常!");
}
catch(ArithmeticException e)
{ ("捕获算术异常!");
}*/
catch(Exception e)
{ ("捕获"+()+"异常!");
} //显示异常信息
finally
{ (" finally i="+i);
}
}
("继续!");
}
}
D:\myjava>java Try2
捕获/ by zero异常! finally i=0
a[1]/1=6 finally i=