display error message
dog 2003-02-25 12:36:54 我要在java中定义自己的error message,比如文件不存在
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
if (in == null)
{
throw new IllegalArgumentException(
"File: " + inputFileName + " not found");
}
运行时,我的error message没有显示。应该如何定义自己的error message,遇到错误后,如何调用?