为何我把main()函数里的System.err.println("xxxx");换成自定义的fail("xxxx");就出错了呢?? public static void main(String[] args) throws IllegalArgumentException 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 System.err.println("Usage: java Delete <file or directory>");改为:Delete.fail("Usage: java Delete <file or directory>");import java.io.*;public class Delete { public static void main(String[] args){ if(args.length!=1){ Delete.fail("Usage: java Delete <file or directory>"); System.exit(0); } try{ delete(args[0]); }catch(IllegalArgumentException e){ System.err.println(e.getMessage()); } } public static int delete(String filename){ File file = new File(filename); if(!file.exists()){ fail("Delete: no such file or directory:"+filename); return 0; } if(!file.canWrite()){ fail("Delete:Write protected:"+filename); return 0; } if(file.isDirectory()){ String[] files = file.list(); if(files.length>0){ fail("Delete:directory not empty:"+filename); return 0; } } boolean success = file.delete(); if(!success){ fail("Delete:deletion failed"); return 0; } return 1; } protected static void fail(String msg) throws IllegalArgumentException{ throw new IllegalArgumentException(msg); }} 因为你的fail会抛出异常,而你的 if(args.length!=1){ System.err.println("Usage: java Delete <file or directory>"); System.exit(0); }没有在捕获异常的范围内 SWT中浏览器对象调用HTML文件 相对路径怎么给? 一个学习中发现的问题,请明白人来解答 android setAdapter出错 谁能帮忙说一下API文档的具体查找方法 JavaBean中catch到的错误如何显示在页面上? 在线等待:这个类偶在JSP里不会调用了,求肋。。。。(这是个加密的类) classpath 的问题!!! 初学者装EditPlus时遇到程序无法运行问题 ■■ 为什么要有Statement ■■ 疑问求答,谢30分 请问 初学者的疑惑!
改为:
Delete.fail("Usage: java Delete <file or directory>");
import java.io.*;public class Delete {
public static void main(String[] args){
if(args.length!=1){
Delete.fail("Usage: java Delete <file or directory>");
System.exit(0);
}
try{
delete(args[0]);
}catch(IllegalArgumentException e){
System.err.println(e.getMessage());
}
}
public static int delete(String filename){
File file = new File(filename);
if(!file.exists()){
fail("Delete: no such file or directory:"+filename);
return 0;
}
if(!file.canWrite()){
fail("Delete:Write protected:"+filename);
return 0;
}
if(file.isDirectory()){
String[] files = file.list();
if(files.length>0){
fail("Delete:directory not empty:"+filename);
return 0;
}
}
boolean success = file.delete();
if(!success){
fail("Delete:deletion failed");
return 0;
}
return 1;
}
protected static void fail(String msg)
throws IllegalArgumentException{
throw new IllegalArgumentException(msg);
}
}
if(args.length!=1){
System.err.println("Usage: java Delete <file or directory>");
System.exit(0);
}
没有在捕获异常的范围内