Java 常見(jiàn)異常lllegalArgumentException

lllegalArgumentException

java.lang.lllegalArgumentException是非法參數(shù)異常，迪常是調(diào)用方法時(shí)引發(fā)的異常。當(dāng)給一個(gè) 方法傳遞的參數(shù)與實(shí)際定義不相符時(shí)，會(huì)拋出lllegalArgumentException異常。

import java.io.File;

//NumberFormatException

public class Demo {

public static String createFilePath(String parent, String filename) throws IllegalArgumentException{ 

if (parent == null)

throw new IllegalArgumentException("文件路徑不能為空！ "); 

if(filename == null)

throw new IllegalArgumentException("文件名稱(chēng)不能為空！ ");

return parent + File.separator + filename;

}

public static void main(String[] args) {

System.out.println(Demo.createFilePath("dir1" ,"file1"));

System.out.println();

System.out.println(Demo.createFilePath(null, "file1"));

}

}