Exception?in?thread?"main"?java.lang.IllegalArgumentException:?D:\eclipse-workspace\project01\src\package1不是目錄
????at?com.javaio.test.FileUtils.listDirectory(FileUtils.java:11)
????at?com.javaio.test.FileUtilTest1.main(FileUtilTest1.java:8)

package?com.javaio.test;

import?java.io.File;
import?java.io.IOException;

public?class?FileUtils?{
????public?static?void?listDirectory(File?dir)?throws?IOException{
????????if(!dir.exists())?{
????????????throw?new?IllegalArgumentException("目錄"?+?dir?+?"不存在。");????????}
????????if(dir.isDirectory())?{//用于判斷file類的對(duì)象是否是目錄
????????????throw?new?IllegalArgumentException(dir?+?"不是目錄");
????????}
????????//list方法用于列出當(dāng)前目錄下的子目錄和文件。
????????String?fileNames[]?=?dir.list();
????????for(String?str?:?fileNames)?{
????????????System.out.println(str);
????????}
????????//如果要遍歷子目錄下的內(nèi)容就需要構(gòu)造成file對(duì)象做遞歸操作，F(xiàn)ile提供了返回對(duì)象的API.
????????File[]?files?=?dir.listFiles();//返回的是直接子目錄(文件)的抽象
????????for(File?file?:?files)?{
????????????System.out.println(file);
????????}
????????if(files?!=?null?&&?files.length?>?0)?{
????????????for(File?file?:?files)?{
????????????????if(file.isDirectory())
????????????????????listDirectory(file);//遞歸
????????????????else
????????????????????System.out.println(file);
????????????}
????????}
????}

}

package?com.javaio.test;

import?java.io.File;
import?java.io.IOException;

public?class?FileUtilTest1?{
????public?static?void?main(String[]?args)?throws?IOException?{
????????FileUtils.listDirectory(new?File("D:\\eclipse-workspace\\project01\\src\\package1"));
????????
????}

}

測(cè)試的時(shí)候?qū)懥撕枚嗄夸浂际钱惓ｏ@示該目錄不存在我都是直接從e盤copy的路徑