Java-源代码-简单例外捕获演练1

最新推荐文章于 2025-10-30 16:56:01 发布

原创最新推荐文章于 2025-10-30 16:56:01 发布 · 618 阅读

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CC 4.0 BY-SA版权

文章标签：

#exception #string #null #class

本文通过三个示例演示了如何在Java中正确地处理NullPointerException和Exception。强调了catch子句中异常参数的声明应遵循从具体到抽象的原则，即先声明特定异常类型再声明其父类型。

public class BadString
{
public static void main(String[] args)
{
  System.out.println("Hello World!");
  String name=null;
  try
  {
   if(name.equals("exception"))
    System.out.println("My name is "+name);
  }
  catch (ArithmeticException e)
  {
   System.out.println("catch an Arithmetic Exception!");
  }
  catch (NullPointerException e)
  {
   System.out.println("catch a Null Porinter Exception !");
  }
}
}

public class catchNullString
{
public static void main(String[] args)
{
  System.out.println("Hello World!");
  String name=null;
  try
  {
   if(name.equals("exception"))
    System.out.println("My name is "+name);
  }
  catch (Exception e)
  {
   System.out.println("catch an Exception!");
  }
  catch (NullPointerException e)
  {
   System.out.println("catch a Null Porinter Exception !");
  }
}
}

public class catchNullString
{
public static void main(String[] args)
{
  System.out.println("Hello World!");
  String name=null;
  try
  {
   if(name.equals("exception"))
    System.out.println("My name is "+name);
  }
  catch (NullPointerException e)
  {
   System.out.println("catch an Null Pointer Exception!");
  }
  catch (Exception e)
  {
   System.out.println("catch a Exception !");
  }
}
}